U.S. DEPARTMENT OF 

HEALTH AND HUMAN SERVICES

National Institutes of Health

National Institute of General Medical Sciences
Written by Alison Davis under contract HHSN263200800496P

Produced by the Office of Communications and Public Liaison

National Institute of General Medical Sciences

National Institutes of Health

U.S. Department of Health and Human Services

To learn more about NIGMS or to order free 

educational resources about science and medicine, 

visit http://www.nigms.nih.gov.

On the Cover

1 Ocean 

2 Foxglove

3 Rainforest

4 Cone snail, Kerry Matz

5 Blood vial

6 Virginia Cornish, Virginia Cornish

7 Head scan

8 Adrenergic receptor

9 Ram Sasisekharan, L. Barry Hetherington

10 Tiny points of light, Sandra Rosenthal,

James McBride, Stephen Pennycook

11 Lola Eniola-Adefeso, Scott Galvin

12 Plant cells

13 Periodic table

14 Medications

15 GFP froglet, Jonathan Slack

16 Multi-well plate

17 Nano rainbow, Shuming Nie

18 Hen egg lysozyme crystals, Alex McPherson

19 Golden gene chips, Hao Yan, Yonggang Ke

20 Plant cells

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2 3

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6 7

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10 11

12

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14 15

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Much of the science described in The Chemistry of Health has been funded

through U.S. tax dollars invested in biomedical research projects at universities.

The National Institute of General Medical Sciences, which funded most of these

research projects, is unique among the components of the National Institutes of

Health in that its main goal is to promote basic biomedical research that at first

may not be linked to any particular body part or disease. In time, however, these

scientific studies on the most fundamental of life’s processes—what goes on

inside and between cells—can shed light on important health issues, including

what causes certain diseases and how to treat them safely and effectively.
Disease...

Pollution... 

Hunger... Global warming... 

Did you realize that chemistry plays a key role in helping us solve some of 

the most serious problems facing our world today?

Chemists want to know. They want to find the building blocks of the chemical

universe—the molecules that form materials, living cells and whole organisms.

Chemists want to create. They want to make useful substances, including 

some that don’t even exist in the natural world.

Many chemists are medical explorers looking for new ways to maintain and

improve our health. Others are helping to preserve our planet by developing 

safe, cheap and efficient ways to make the materials we use every day.

Explore more @ http://www.nigms.nih.gov/ChemHealthWeb

• Meet Today’s Chemists

• Get a Free Poster

• Play Interactive Games and Solve Puzzles

• Check Out Our Molecule Gallery
2 National Institute of General Medical Sciences

Chemists want to know about

matter and its properties—the

density, acidity, size and shape 

of molecules. Biologists want 

to understand living things and

how they interact with their 

environment.

And chemistry and biology are

more connected than you might think.

Using knowledge about atoms,

forces and molecules, chemists

learn about unfamiliar substances,

but they also learn about organisms

and body processes.

One of the most amazing 

triumphs of the human body is the

fact that all we really need to do to

keep it running is to eat and sleep.

The rest seems to take care of itself.

But a lot of chemical reactions are

going on 24/7 to make this happen.

Metabolic factories recycle the

components of digestion back into

basic building blocks from which 

our tissues and organs are built.

Using proteins, the genetic 

material DNA and RNA, sugars 

and fats, chemical reactions let 

a sprained ankle heal properly, 

make our hair and fingernails grow 

a little bit every day and give us

energy to text our friends or ace a

geometry test.

The main players in metabolism

are enzymes, molecules that speed

up the chemical reactions in our

bodies. Because they make reactions

go faster than they would on 

their own, enzymes are biological

catalysts.

Consider this: Without the help 

of enzymes, the conversion of 

nutrients and minerals into usable

biological molecules such as proteins, DNA and RNA might take

weeks, even years! Enzymes are

essential to life, since our bodies

Millions of chemical reactions in our bodies help us stay active.

cannot afford to wait that long to

receive the important products of

chemical reactions.

In speeding up reactions, enzymes

act like the accelerator pedal of a car.

But they also play the role of matchmaker, bringing together starting

materials (substrates or reactants)

and converting them into finished

materials (products). 

Most enzymes reside inside cells.

If cells get damaged, they break

apart and spill their contents into

neighboring body fluids, like blood.

That is why higher-than-normal levels

of enzymes in blood—revealed in 

a simple blood test—can signify

trouble in tissues or organs where

those cells normally live.

When enzymes are not working

properly, they can cause disease.

For example, cancer can develop

Actions & Reactions

when the enzymes that copy DNA

make mistakes. These errors can

produce a misspelled gene that

makes a defective protein or no 

protein at all. If that protein is the

one that keeps a set of cells from

multiplying out of control, you can

imagine how its absence could

bring about serious problems.

Inside the body, enzymes are

never lonely. They link together,

forming vibrant networks and pathways. And so our metabolism is

really just a collection of enzymecatalyzed reactions that build and

break down organic molecules in

food, producing or consuming

energy in the process. But to be

effective, the reactions need to work

together in a coordinated way.

The chemical reactions of metabolism occur over and over again.

The main players in metabolism are enzymes, molecules that

speed up the chemical reactions in our bodies.

ANDY COMBS
http://www.nigms.nih.gov/ChemHealthWeb 3

that every woman of childbearing age

supplement her diet with 400 micrograms of this vitamin.

Folic acid does its good deeds 

by improving the fit between various

enzymes and their substrates. One 

of these enzymes speeds up the 

conversion of a potentially harmful

molecule called homocysteine to

methionine, a nontoxic amino acid 

that the body needs. Thus, folic acid

lowers blood levels of homocysteine,

which in excess is a risk factor for

heart attacks and strokes. 

Folic acid helps

enzymes and 

substrates get 

together.

Much like a cascade of dominoes,

the product of one chemical reaction

becomes the substrate for another.

By understanding the language of

the body’s metabolic communication

systems, scientists can find ways to

patch the circuits when they become

broken from injury and disease.

One secret to an enzyme’s success is its three-dimensional shape.

An enzyme is shaped so that it 

can hug its substrate tightly. This

molecular embrace triggers chemical

changes, shuffling attractive forces

and producing new molecules. 

Only enzymes that have an exact 

fit with their substrates do a 

decent job of speeding up 

chemical reactions.

Many proteins need help from

one or more other proteins to

perform their jobs well. Proteins

that interact often change their

shape as a result of the encounter.

The differently shaped protein is

better able to capture its substrate

and make a chemical reaction

happen. Sort of like rearranging

seats in a room to accommodate

more guests, the reshaping of 

proteins can make extra space for

substrates and products to fit.

In addition to proteins, other

helper molecules called cofactors 

are necessary ingredients for many

enzyme reactions. Folic acid, a 

B vitamin, is one of them.

Researchers have known for

decades that folic acid can protect

against certain birth defects—such

as spina bifida—that develop during

the first few weeks after conception.

For this reason, the U.S. Food and

Drug Administration recommends

Explore more @ http://www.nigms.nih.gov/ChemHealthWeb

“Chemistry is my favorite science because it’s

rooted in creativity—inventing new

molecules with unanticipated functions.”

—Virginia Cornish

Meet...

Virginia Cornish

CHEMICAL BIOLOGIST, New York City

Cornish uses genetic engineering methods to mix 

and match natural substances in new ways.

BORN IN:

Savannah, Georgia

FAVORITE KIND OF MUSIC:

College music stations that 

play everything

BEST THING TO DO ON A SNOW DAY:

Go sledding with my young kids

JOB SITE: Columbia University

FAVORITE SUBJECTS IN HIGH SCHOOL:

Chemistry and poetry
4 National Institute of General Medical Sciences

Lipids and carbohydrates are 

the scientific names for fats and

sugars. These natural substances

do a lot to keep us healthy. Along

with giving us energy, they help

cells move around the body and

communicate.

FATS

Eating healthy means that you need

to be careful about the amount of fat

in your diet. But a certain amount of

fat is really necessary: All humans

need lipids, called essential fatty

acids, from food because our bodies

can’t make them from scratch. Some

body fat is also necessary as insulation to prevent heat loss and to

protect vital organs from the strain

of routine activities.

Lipids in adipose tissue (fat cells)

are a major form of energy storage

in animals and people. The “fatsoluble” vitamins (A, D, E and K) are

essential nutrients stored in the liver

and in fatty tissues. Triglycerides,

another type of lipid, are especially

suited for stockpiling energy because

of their high caloric content. When

we need energy, our bodies use

enzymes called lipases to break

down stored triglycerides into smaller

pieces that participate directly 

in metabolism.

The mitochondria in our cells 

ultimately create energy from these

reactions by generating adenosine

triphosphate, or ATP, the main currency of metabolism.

In addition to providing and 

storing energy, lipids do many other

things. They act as messengers,

helping proteins come together in 

a lock-and-key fashion. They also

start chemical reactions that help

control growth, immune function,

reproduction and other aspects of

basic metabolism.

The lipid molecule cholesterol 

is a key part of the plasma membrane, a coating that wraps around

every cell in the human body. 

Although it does act as a protective barrier, the plasma membrane 

is less like a rigid wall and more 

like a pliable blanket. In addition to

lipids, the plasma membrane contains sugars that stick out from its

surface and proteins that thread

through it.

It is an orderly arrangement 

of ball-and-stick molecules called

glycolipids (lipid chains with sugars

attached) and phospholipids 

(lipids marked with cellular tags

called phosphates).

When aligned “tail-to-tail,” these

fat-containing molecular assemblies

resemble a double array of matchsticks lined up perfectly end-to-end.

The membrane forms more or

less automatically when the lipid 

end of each glycolipid or phospholipid matchstick is attracted to oily

substances: other lipids. The other

matchstick end, containing a sugar

or phosphate molecule, drifts naturally toward the watery environment

typical of the areas inside or

between cells.

Membranes are a hallmark of

how organisms evolved the ability 

to multitask. Membranes allow cells

to keep proteins and other molecules in different compartments so

that more than one set of reactions

can occur at the same time.

In addition to the plasma membranes around cells, organelles

inside cells are wrapped by similar,

lipid-containing membranes that

encase specialized contents.

Membranes are a hallmark of how organisms evolved 

the ability to multitask.

The plasma membrane is a perfect example of the rule that oil and water don’t mix.

Inside the Cell

Carbohydrate

Plasma 

membrane

Glycoprotein

Glycolipid

Cholesterol

Phospholipid

Protein

Outside the Cell

You Are What You Eat!
have a tough time forcing them to

connect one way instead of another.

One reason chemists want to

make sugars from scratch is to

design vaccines that target the

surfaces of bacteria and viruses.

Sugars attached to proteins, called

glycoproteins, are an important part

of cell membranes. Jutting out from

the surface of nearly all cells, these

sugary signposts are a cell’s identification. They are sort of like cellular

address labels.

Also called glycans, these

branched molecules serve as

specialized receptors that act 

as docking stations for proteins

on other cells. Each organ and

tissue has its own special

glycans, which grant access

only to those molecules 

that know the proper 

molecular “code.”

Every type of virus we

encounter can only grip a

certain set of glycans with

precisely the right connections at their tips. In this

manner, the types of glycans that a virus latches

onto can determine how

it will make you sick. For

example, some viruses

prefer glycans in the

lungs, while others like 

the intestines or the throat.

Explore more @ http://www.nigms.nih.gov/ChemHealthWeb

“I volunteer to teach in Asia 

every summer. I enjoy sharing 

my experiences with the next

generation of world health 

sleuths!” —Ram Sasisekharan

Meet...

Ram 

Sasisekharan

BIOENGINEER, Cambridge, Massachusetts

Sasisekharan researches carbohydrates—

indispensable natural molecules used by 

all life forms.

L. BARRY HETHERINGTON

http://www.nigms.nih.gov/ChemHealthWeb 5

BORN IN: Chennai, India

FAVORITE FOOD: Pasta

PLAN A: When I was young, I always 

imagined I’d be a medical doctor

JOB SITE: MIT, Singapore, Bangkok...

anywhere the need arises

FAVORITE WEEKEND PASTIMES: Jogging, 

spending time with family, enjoying

and creating art, and being outdoors

Simple sugars link in many orientations 

to make oligosaccharides.

Amino acids link head-to-tail to 

make proteins.

SUGARS

In chemistry, a polymer is a substance that contains repeating units:

Polyester and many plastics are

examples of synthetic polymers.

Proteins, nucleic acids and carbohydrates are natural “biopolymers”

that consist of chains of amino acids,

DNA, RNA or sugar molecules.

How do our bodies make biopolymers? You guessed it: enzymes.

Scientists can also make some

biopolymers in the lab. DNA, RNA

and proteins are fairly simple to 

construct—so simple that scientists

today routinely synthesize thousands

of different versions at once on

wafer-like chips similar in size to

those used in computers.

But complex carbohydrates—

chains of sugars—are a different story.

Why is making sugar chains so

hard? The answer lies in their fundamental structure.

Proteins are strings of amino

acids that can only fit together one

way, head-to-tail. In contrast, long,

branched chains of sugars called

oligosaccharides can fit together in

dozens of different ways. Chemists
6 National Institute of General Medical Sciences

tubes and columns, each only as big

as a fraction of a drop of water.

Chemists want to use tiny devices

to deliver drugs to specific sites in

the body, allowing for highly targeted treatments with minimal 

side effects. Other devices could

measure cholesterol, sugar and

electrolytes in blood, saliva, urine 

or tears.

Small tools also allow scientists 

to watch biology happen in real time.

Bright, rainbow-colored dyes and a

green fluorescent protein (GFP) that

comes from jellyfish let scientists

track how molecules move around in

living organisms. Often, these experiments are done in simple organisms

like bacteria and yeast, which consist 

of only a single cell but have inner

workings with a striking degree of

similarity to human biology.

In studies with human cells,

researchers have tagged cancer

cells with GFP to watch how they

spread to other parts of the body.

They mark insulin-producing cells 

in the pancreas to see how they’re

made and gain insights into new 

diabetes treatments.

Using another technology, called

quantum dots, scientists use 

Cool Tools

Quantum dots are nanocrystals that radiate brilliant colors when exposed to ultraviolet light.

SHUMING NIE

microscopic semiconductor crystals

to label proteins and genes. Quantum

dots enable the study of molecules

in a cell as a group, rather than 

in isolation.

Dots of slightly different sizes

glow in different fluorescent colors—

larger dots shine red, while slightly

smaller dots shine blue, with a whole

spectrum in between. Researchers

can create up to 40,000 labels by

mixing quantum dots of various

colors and intensities, much like an

artist mixes paint.

Another group of modern chemistry tools includes sensors, devices

that measure a physical quantity and

convert it into a signal that can be

read by an observer or instrument.

We use sensors all the time in

our daily lives. A simple example is 

a thermometer, which transforms 

a measured temperature into the expansion and contraction of a liquid

that can be read on a calibrated

glass tube. Another is a touchsensitive elevator button.

Scientists and doctors use sensors all the time, too. Biosensors

can scan a wide range of biological

materials, from microbes, enzymes

and antibodies to pollutants. The

output, or signal, varies widely as

well, ranging from color to light 

to electricity. 

One of the most common 

examples of a health-related biosensor is a blood glucose monitor.

This miniature device uses the

enzyme glucose oxidase to break

down blood glucose and produce 

a readable signal, which indicates

how much sugar is present in a

person’s blood. It is a vital tool for

people with diabetes who must

check their blood sugar several

times a day.

Chemists are masters of materials,

and they often work in the world 

of the very small. Using tools made

from the building blocks of life,

chemists can spy on the movements of single molecules and

make miniature devices that pick

up trace levels of contaminants in

food and the environment.

The space between two carbon

atoms within a molecule is about

one-tenth of a nanometer. The DNA

double helix has a diameter of about

two nanometers. The smallest bacteria, on the other hand, are much

bigger: a few hundred nanometers

in length.

A nanometer is one-billionth 

the length of a meter—or about 

the circumference of a marble in

comparison to that of the Earth!

And nanotechnology is the study

of the control of matter on an atomic

and molecular scale. Some say it is

chemistry by a different name. 

Fittingly, some entire modern

chemistry “labs” are extremely

small—cramming all the necessary

tools and molecules onto a rectangular wafer smaller than a business

card. Such mini-machines contain 

an expansive network of miniature
http://www.nigms.nih.gov/ChemHealthWeb 7

Explore more @ http://www.nigms.nih.gov/ChemHealthWeb

“I never took a formal cell biology

class, but I’ve been surrounded by 

talented cell biologists who taught

me most of what I know.” —Jack Taunton

Taunton custom-makes molecules in his lab to

figure out how cells do so many amazing things. 

BORN IN: Houston, Texas

BEST WAY TO SPEND A WEEKEND: Playing and

listening to music, reading chemistry and cell

biology papers, designing small molecules on

the backs of discarded envelopes

JOB SITE: University of California, San Francisco

FAVORITE MUSICIANS/COMPOSERS: Sonic Youth, 

Béla Bartók, Ornette Coleman, Jimi Hendrix, 

Charles Mingus, J.S. Bach, Tom Waits, 

The Beatles, John Coltrane, Lee Morgan

Meet...Jack Taunton

CHEMIST AND CELL BIOLOGIST,

San Francisco, California

How Small Is Small?

Nanotechnology is the study of the control of matter on an

atomic and molecular scale. 

Some biosensors rely on modified microorganisms that detect

toxic substances at very low levels.

They can give us early warning of

environmental contaminants, poisonous gases and even bioterror

agents, such as ricin or anthrax.

Chemistry also plays a central 

role in making biomaterials such 

as artificial joints, implants, heart

valves and skin patches filled with

hormones or other medicines.

Efforts to engineer artificial

organs—like a liver, pancreas or

bladder—also hinge on chemistry.

Researchers have made test

versions of many artificial organs.

And some, like artificial skin for 

the treatment of severe burns 

and traumatic injuries, are already 

in wide use.

10-1 1 10 102 103 104 105 106 107 108 

Nanometers

Water Glucose Antibody Virus Bacterium Cancer cell A period Tennis ball

NIH

Nanodevices

Nanopores

Dendrimers

Nanotubes

Quantum dots

Nanoshells
What He’s Doing

Sometimes, a drug doesn’t work like it’s meant to

because it isn’t absorbed properly or it doesn’t reach

the correct spot in the body. These adverse drug

reactions are one of the leading causes of hospitalization and death in the United States. 

Gus Rosania thinks that the precise location of a

drug within a cell is a key clue to its effectiveness 

and safety. And so he is using powerful microscopic

techniques to track where drugs go inside cells and what

they do when they get there. 

To do this efficiently and on a large scale, Rosania is

using “machine vision.” This technique joins imaging to

computer methods that can screen large collections of

molecules for their locations inside cells. 

His Findings

Rosania treated human cells growing in lab dishes with a

huge collection of molecules that glow in different colors

in response to certain wavelengths of light. Computerized

microscopes scanned the treated cells, analyzing more

than 15,000 individual molecular pictures.

The experiment was a test to see if such a “highthroughput” approach—beginning with thousands of

different potential molecules—could be used in the

process researchers use to look for would-be medicines.

Rosania concluded that his machine-vision technique was

successful in automatically analyzing where the dye molecules traveled inside cells.

One advantage this technique has over manual labor—

a person sitting at a microscope—is scale. The process

can be done quickly and efficiently, saving time and money

and enabling many more molecules to be tested in the

search for new and safer medicines.

8 National Institute of General Medical Sciences

“My dream is to develop technologies for 

making better and safer medicines. I want to

help people live longer, healthier and happier.”

PHARMACEUTICAL SCIENTIST, Ann Arbor, Michigan 

Meet more chemists @ http://www.nigms.nih.gov/ChemHealthWeb

BORN IN

Barranquilla, Colombia

DREAM CAR 

A large, purple van that seats 

eight and runs on air and sunlight

FAVORITE SEASON

The one we’re in! I live in the present

JOB SITE 

University of Michigan, Ann Arbor

FAVORITE PASTIME

Laughing until my belly aches

Meet...

Gus Rosania
http://www.nigms.nih.gov/ChemHealthWeb 9

“I started my career as a high school science

teacher, but I wanted to learn more about

research, so I went to graduate school.”

What She’s Doing

Our bodies, like nearly all living things on 

the planet, run chemical reactions in watery

fluids at a neutral pH. Naturally occurring

metals help these processes occur safely

and efficiently.

Cathy Drennan studies how these metals do

such important jobs in biology. Since metals are

key components of many enzymes, cell proteins

and even medicines, this work is really important for 

our health.

Metals also act as molecular helpers in chemical

reactions that rid the atmosphere of pollutants like carbon

monoxide. So Drennan’s work goes toward protecting the

environment, too.

Her Findings

Using physics and computer science approaches, Drennan

pieces together the three-dimensional shapes of proteins.

She did this recently with an iron, nickel and sulfurcontaining enzyme that converts carbon dioxide first into

carbon monoxide, then into acetyl CoA, a key molecule 

in energy production.

Drennan was quite surprised to find that metals help this

enzyme twist itself in a way that creates a molecular tunnel

for the carbon monoxide to travel through. For this experiment, she used an inventive approach that substituted

xenon for carbon monoxide. Both are gases of about the

same molecular size, but xenon can be used more readily 

in a freeze-frame molecular snapshot of the enzyme.

Why did nature create such an extremely long tunnel 

in a protein? Drennan thinks it’s an elegant design for an

assembly line-like structure that assures the quick and

efficient production of the vital molecule acetyl CoA.

Meet more chemists @ http://www.nigms.nih.gov/ChemHealthWeb

Meet... 

Cathy Drennan CHEMIST AND BIOPHYSICIST, Cambridge, Massachusetts

BORN IN

Newton, Massachusetts

FAVORITE TEAM 

Boston Red Sox

ALTERNATE CAREER CHOICE

Politician

JOB SITE 

MIT

BEST READING

Murder mysteries 
10 National Institute of General Medical Sciences

Our world is full of molecules with

natural healing power. Chemists

examine substances produced for

self-defense by microbes, algae,

plants and animals to learn how 

to make powerful antibiotics,

painkillers, cancer treatments and

other medicines.

Snakes, spiders and sea snails 

use venom to kill their prey. Poisonous dart frogs, wasps and hemlock

trees protect themselves with

poison. Penicillin is a bacterial poison

made by a mold. The process of 

evolution has shaped inventive ways

for organisms to keep themselves

safe from predators. 

The enzymes in our bodies are

also shaped by millions of years of

evolution. Because all living things

share the same basic biochemistry,

natural products frequently interact

with the same molecules in people

as they do in other organisms.

So chemists want to understand

much more about natural products,

and a key step in doing that is figuring out how the molecules are made.

That information is important for two

reasons. First, it can uncover related,

and sometimes even more desirable,

molecules. Second, understanding

natural processes helps chemists

learn how to make and refine chemicals in the lab.

Human use of microorganisms

extends back to prehistoric times,

when people began making wine and

leavened bread. Recently, in an area

of chemistry called metabolic engineering, researchers have used the

tools of molecular biology to produce

chemical substances that, in many

cases, never before existed in nature.

Sometimes, these are referred to as

“unnatural” natural products.

Metabolic engineers use living

systems to turn simple sugars and

other small molecules into promising

new antibiotic medicines, biofuels

and other agricultural and veterinary products.

Unlike a factory production

scheme, metabolic “labs” carry 

out multiple chemical reactions in 

a single pot—a cell—without the

need for time- and labor-intensive

separation and purification steps.

To work their magic, chemists

need to understand and be able to

reproduce the biochemical circuits

these organisms routinely use to

break down food and produce

energy, as well as those pathways

that re-use the building blocks to

make bigger molecules. The products of metabolism are called

metabolites.

More than a hundred metabolites are currently used as common 

medicines for people and animals.

Examples include the antibiotics

erythromycin and tetracycline, 

a cholesterol-lowering drug called

lovastatin (Mevacor®) and a fleabusting pet medicine called 

avermectin. All of these are polyketides, a class of metabolites 

that soil bacteria manufacture 

naturally and abundantly.

Chemicals from nature have also

proven effective against not-soobvious conditions like heart disease,

Nature’s Products

Conus geographus (“geography cone”) is one 

of the few snails that can kill a human. Scientists

have retooled cone snail poisons to make the

painkiller Prialt ®

.

KERRY MATZ

Tropical rainforests are often rich sources of chemical diversity.
http://www.nigms.nih.gov/ChemHealthWeb 11

depression and epilepsy. Sometimes,

a natural substance will inspire medicines for two or more diseases.

There are also many natural

products that look good but simply

can’t be made in the lab. Many have

very complex structures that are too

difficult and expensive to manufacture on an industrial scale. One

example is the painkiller morphine.

Another is the cancer drug paclitaxel (Taxol ®). An entire Pacific yew

tree would have to be cut down to

extract enough active ingredient

from the bark to make a single dose

of this medicine. But this slowgrowing tree is an environmentally

threatened species.

Thankfully, synthetic chemists

have figured out a way to make the

drug from a readily available ingredient that is abundant in the more

plentiful European yew tree. 

Chemists also get creative by

inventing techniques unavailable 

to woodland or jungle creatures.

Using lab tools and tricks—

changing reaction conditions or

adding catalysts—chemists can

make huge quantities of molecules

whose structures are slight variations of a natural product.

Researchers travel the world 

to obtain natural samples to analyze

and evaluate for the purposes of

drug discovery. Collecting natural

materials can involve harvesting

reptile venom, diving for poisonous

marine life and hiking through

jungles to identify rare plants.

Scientists have already found 

lots of promising substances, but

they think that many more are still

out there.

Having an appreciation for

different cultures is really important

for this kind of work. Often, talking

with locals gives key insights about

potential uses for natural products.

Such “bioprospecting” has to be

thoughtful and respectful. Many of the

areas of rich biodiversity are in tropical

forests and coral reefs in some of the

poorest parts of the world, and these

ecosystems must be protected.

One way to do this is through

chemistry that synthesizes natural

products and helps minimize the 

use of natural resources.

BORN IN: Harvard, Nebraska

FAVORITE FOOD: Beef, but with 

guilt because of the high energy cost 

(8 pounds of corn are needed to produce 

1 pound of beef)

JOB SITES: Lawrence Berkeley National

Laboratory and University of California, Berkeley

FAVORITE TEAM: Nebraska Cornhuskers, football

BEST VACATION: On the beach in Hawaii!

The process of evolution has shaped inventive ways for

organisms to keep themselves safe from predators.

Explore more @ http://www.nigms.nih.gov/ChemHealthWeb

“We could potentially turn any plant—

grass, weeds, even paper waste—into

energy.” —Jay Keasling

Keasling uses bacteria or yeast as factories to make

medicines, plant-based fuels and other products that people

want and need.

Meet...

Jay Keasling

CHEMICAL ENGINEER, Berkeley, California
Enzyme Reaction

12 National Institute of General Medical Sciences

of which can be hazardous—and

less waste.

Harnessing biology’s magic

through chemistry underlies the field

of biotechnology—the use of biological systems or living organisms to

make useful products and processes.

Biotechnology has applications in a

wide range of areas that benefit the

United States and the world.

Examples include genetically

engineered medicines and agricultural processes that reduce farmers’

dependence on herbicides and

insecticides. 

Other applications of biotechnology include biodegradable plastics

and environmental cleanup tools. 

For example, fatty acids are used as

detergents and as biofuels, which

are less damaging to the environment than many coal-based fuels. 

Taking advantage of microbes’

innovative metabolism and defense

mechanisms can help us preserve

our environment, as well. This is the

case for methane, the main component of natural gas that is used in

industrial chemical processes and is

second only to carbon dioxide as a

greenhouse gas that contributes to

global warming. 

Methane is chemically inert, meaning it does not break down easily. But

for some bacteria that live in extreme

environments like hot springs, chewing up methane is a way of life (see

diagram, above). Understanding how

enzymes in these bacteria convert

methane into methanol and water

could possibly spur more efficient use

of the world’s supply of natural gas.

Some chemists study the role 

of metal-containing molecules in

biological systems (see page 9). Many

processes in our bodies—like respiration and reproduction—depend on

metals like iron, zinc and copper.

Iron, for instance, helps the protein

hemoglobin transport oxygen to

organs throughout the body. Many

metals act to stabilize the shapes 

of enzymes.

Since metals are elements, the

building blocks of all chemical compounds, they are already in their

simplest form and our bodies cannot

break them down.

Chemistry...For a Healthier

In some countries, biodiesel is less expensive 

than conventional diesel.

H

C

H

H H

H

C

H

H OH

2H O2

H2O

2 Hydrogens

Methane (Gas) Water Methanol (Liquid)

1 Oxygen

The enzyme methane monooxygenase converts methane into methanol, producing water 

as a byproduct. Methanol is a liquid that can be transported much more easily than methane, 

a gas that is hard to keep contained.

BOB TUBBS, WIKIMEDIA COMMONS

Chemists want to understand 

how biology works so they can

manipulate it. Inventing environmentally friendly approaches that

make reactions more efficient 

and produce minimal toxic byproducts is an important goal of

modern chemistry.

Whether inside the body or in 

the lab, all chemical reactions do 

the same thing. They convert starting materials, or reactants, into

products. Catalysts make these 

reactions go faster. 

A catalyst works by providing a

route for the reaction pathway to

make its product using less energy.

Catalysts are facilitators—they

are not used up in the reaction and

can be recycled. Researchers are

continually looking for catalysts

that are more efficient and friendlier to the environment. Such

catalysts are an important aspect

of “green chemistry.”

One recent advance in this area 

is the development of “click chemistry,” which allows chemists to tailor

reactions very precisely. Thus, they

can generate substances quickly 

and reliably. Click chemistry also

produces fewer byproducts—some
BORN IN: Hong Kong

JOB SITE: University of Arizona,

Tucson

ALTERNATE CAREER: Medical doctor

LAST MOVIE YOU SAW: The Bourne 

Ultimatum and Ocean’s Thirteen

BEST THINGS TO SEE OR DO IN TUCSON: Desert

Museum, Gem Show, hiking at Sabino Canyon

and Saguaro National Park, bird watching, Kitt 

Peak National Observatory, Mt. Lemmon, Old

Tucson Studios and the Tombstone Epitaph

http://www.nigms.nih.gov/ChemHealthWeb 13

Thus, our bodies take great care

to make sure metals go only where

they need to go, and in exactly the

proper amount. In many cases that

means one or two atoms in an individual cell. That’s in contrast to

thousands to millions of proteins 

or other molecules.

Some toxic metals aren’t good 

in any amount. They can poison

important enzymes, preventing

them from doing their jobs and

keeping the body healthy. Lead

from the environment, for instance,

World

Explore more @ http://www.nigms.nih.gov/ChemHealthWeb

“Don’t just sit in the dark and wonder what

comes next. Instead of panicking, get more

information.” —Serrine Lau

Meet...

Serrine Lau

TOXICOLOGIST, Tucson, Arizona

Lau studies the ways in which tiny variations in human 

DNA influence whether we get sick when we’re exposed 

to chemicals in the environment.

Researchers are continually

looking for catalysts that are

more efficient and friendlier

to the environment.

can mess up the body’s synthesis 

of a vital component of hemoglobin

called heme, disabling the blood’s

oxygen transport system.

Certain forms of mercury can 

be deadly, causing irreversible damage in the brain. Other dangerous

metals, such as arsenic, cause

cancer in the skin and lungs. Recently,

scientists discovered single-celled

algae that thrive in Yellowstone

National Park hot springs and that

chemically change arsenic to make

it less hazardous. Such natural

cleansers may find use in reclaiming

mine waste or creating safer foods

and herbicides.

Scientists are working to

eliminate these and other harmful

substances from the environment

and also to detect and reduce

human exposure to such substances.

The medical researchers who 

study the harmful effects of chemicals on living organisms are 

called toxicologists.

Some focus on forensics,

combining toxicology, chemistry,

pharmacology and medicine to 

help criminal investigations of 

death, poisoning and drug use.

These researchers record

symptoms reported by a victim 

as well as any evidence collected

that could narrow the search for 

a perpetrator. This evidence could

include pill bottles, powders and

trace residues of chemicals. Since 

it is rare for a chemical to remain 

in its original form after being

ingested, toxicologists rely on a

solid understanding of metabolism

and of chemical reactions to get 

the job done right.
14 National Institute of General Medical Sciences

Lots of could-be medicines look

good on paper—or on a computer

screen—but a drug can only do 

its intended job of treating a symptom or fighting a disease if it gets

to the right place in the body to 

do its job. That’s where chemistry

plays such a big role, in tweaking

molecules to interact appropriately

with the body.

A lot of the most important medical progress in recent history has

come from the development of

powerful antibiotics and vaccines to

treat infectious diseases caused by

bacteria, viruses and parasites. But

those breakthroughs have come

with a cost—microorganisms have

learned how to fight back, and with

a vengeance.

The misuse of antibiotics is the

most common reason why antibiotic

resistance is such a significant

public health problem. These drugs

are sometimes overprescribed by

doctors, and many people fail to

finish a full prescription.

What’s the problem? An antibiotic

drug treats infection by knocking out

hundreds of strains of “sensitive”

bacteria in the body. But left behind

are many nonsensitive, or resistant,

strains. With no stops in place, 

the resistant microbes repopulate

themselves rapidly.

MRSA, or methicillin-resistant

Staphylococcus aureus, is a 

bacterium that causes difficultto-treat infections in humans, and 

its prevalence has been on the 

rise. Making matters worse, 

MRSA has become resistant to

most disinfectants and antiseptics

used in hospitals.

Chemists are well aware of 

the public health danger posed 

by MRSA and other resistant

organisms. They are working hard

to outwit microbes that develop

resistance. New forms of antibiotic

drugs are currently being developed, and researchers are trying to

design them to target vulnerable

molecular regions of enzymes

within bacteria.

As the name suggests, medicinal

—also called pharmaceutical—

chemistry is an area of research 

that focuses on designing and

making drugs of all sorts. The first

step in this process is identifying

new molecules.

Years ago, medicinal chemists

spent most of their time isolating

interesting molecules from living

organisms, mainly plants. Today,

however, chemists working in this

area are equally concerned with 

finding good ways to make these

molecules in the lab. Medicinal

chemists also work out the best 

way to deliver the new drug: as a

capsule, tablet, aerosol or injection.

Identifying a molecule with a 

specific medicinal effect—like

lowering cholesterol or killing only

tuberculosis bacteria—takes time

and patience. But a strategy called

combinatorial chemistry can help a

lot. In this process, chemists create

and then sift through immense collections, or “libraries,” of molecules.

The newly identified molecules, or

“leads,” are then tested for their

usefulness in treating disease in 

animals and people. 

Just like an online catalog helps

you find books in the library or in a

bookstore, combinatorial chemistry

helps find molecules in a chemical

library. It also usually involves computers to help a chemist find

molecular matches that meet

defined criteria.

Chemical libraries consist of a

diverse matrix of thousands or even

millions of different molecules made

from just a few starting chemical

building blocks. Each chemical has

associated information about its

chemical structure, purity or other

characteristics stored in some kind

of database.

Chemistry Meets Medicine

Staphylococcus aureus bacteria are normal residents of our skin. However, MRSA is a strain of these 

bacteria that has become resistant to antibiotics like methicillin.

Synthesizing new molecules

or drugs involves much more

than following a simple recipe.

JANICE HANEY CARR, CDC
companies used to produce

medicines that contained equal

portions of the left- and righthanded versions. That is because 

it is usually much less efficient and

more expensive to produce only 

one enantiomer of a drug. Over 

time, however, chemistry research

has taught us the importance 

of making single-handed

compounds.

This solves two problems.

The first is eliminating

enantiomers that are

dangerous. And in the

vast majority of cases,

most drugs produced

as left- and righthanded mixtures are

only half as strong 

as they could be,

because one hand

does nothing more

than dilute the 

final mixture.

http://www.nigms.nih.gov/ChemHealthWeb 15

Many properties help determine a

molecule’s potential as a drug. These

include its chemical makeup and

stability, and its solubility (how well

it dissolves in water or body fluids).

Synthesizing new molecules 

or drugs involves much more than

following a simple recipe. That’s

because chemical reactions turn out

two, mirror-image results: a “left”

and a “right” version of a molecule. 

The molecular building blocks of

proteins, sugars and DNA and RNA

all have this property, which is called

chirality. The term stems from the

Greek word for “hands,” the most

familiar chiral objects.

Chemists call the two mirror

images of a molecule enantiomers.

Many chemical reactions generate 

a mixture of equal amounts of the

two enantiomers. This matters when

it comes to making a small molecule,

such as a drug, that must fit precisely into a uniquely shaped cavity

of a body protein. Whereas the lefthanded version may fit perfectly into

the correct space inside the protein,

its right-handed counterpart couldn’t

squeeze in, no matter what.

To manufacture products quickly

and cost effectively, pharmaceutical

Hands are familiar chiral objects.

“Discovering new medicines is 

very exciting. It’s rewarding to be 

a chemist working in a field where

your research can possibly help so

many people. I can’t think of a career 

I would rather do.” —Andy Combs

Meet...

Andy Combs

MEDICINAL CHEMIST,

Wilmington, Delaware

An executive director at a biotech company, 

Combs designs and makes new molecules to 

suppress overactive enzymes that may cause cancer.

BORN IN: Argentia, Newfoundland. Then we moved

to Maryland, and I grew up in Wisconsin. My dad

was in the Navy

JOB SITE: Incyte Corporation

WHAT YOU WOULD BE IF NOT A CHEMIST:

I thought I was going to be an artist and 

a doctor

HOBBIES: Being outdoors, hiking, boating,

fishing, hunting and gardening. Wakeboarding on the lakes in Wisconsin and

New Hampshire

A RECENT VACATION: Scuba diving with

my family at Little Cayman Island and

seeing all the cool creatures

Explore more @ http://www.nigms.nih.gov/ChemHealthWeb
What Is

Chemistry? 

Better Health. Chemists make tools to explore biology, teaching us how disease

starts and finding ways to stop it. They study substances from nature to create 

new antibiotics, pain medicines and cancer drugs. 

Help for the Environment. Efficient and clean chemical reactions protect our 

planet while allowing us to enjoy the foods and other products we need and 

want. Chemists devise new methods to reduce or eliminate pollutants.

A Creative Pursuit. Making molecules is kind of like sculpting, painting or 

even composing. Chemists employ the design rules of nature to produce new 

materials, many of which become part of everyday life.

An Appealing Combination. Many chemists are drawn to the field because it

merges science, art and the beauty of nature in interesting ways that help people.

You Could

Be a Chemist!

Explore more @ http://www.nigms.nih.gov/ChemHealthWeb

• Meet Today’s Chemists

• Get a Free Poster

• Play Interactive Games and Solve Puzzles

• Check Out Our Molecule Gallery
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in the United States shall, on the grounds of race, color, national origin, handicap, or

age, be excluded from participation in, be denied the benefits of, or be subjected to

discrimination under any program or activity (or, on the basis of sex, with respect to

any education program or activity) receiving Federal financial assistance. In addition,

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subcontractors in the performance of Federal contracts, and Executive Order 11246

states that no federally funded contractor may discriminate against any employee 

or applicant for employment because of race, color, religion, sex, or national origin.

Therefore, the programs of the National Institute of General Medical Sciences must 

be operated in compliance with these laws and Executive Orders.

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This publication can be made available in formats that are more accessible to 

people with disabilities. To request this material in a different format or to order

additional copies, contact the NIGMS Office of Communications and Public Liaison 

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have questions about this publication, you can use the same contact information 

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