### substance | pigment:

Natural pigment
* Most natural pigment uses in food products.
* can come from just about anything.
* make exquisite, mellow colors.
* seem to provide some protection against sun-induced skin damage.
+ Pigment: Color :: Materials :: Chemical synthesis
  * A 'pigment' is something that is added to something else to give it color. Natural pigments can come from just about anything. Pigments can be made from animals, plants, rocks and minerals or even the ground itself, for example clay plus salts. Pigments can also be created by people.

Photosynthetic pigment
* Most photosynthetic pigment absorbs light
  - includes chlorophyll
* Some photosynthetic pigment gives chloroplasts.
* absorb in the visible range of the electromagnetic spectrum.
* use primarily the visible light portion of the electromagnetic spectrum.

Phycocyanin
* enhances the immune system.
* is known as a natural blue-colored pigment and consists of proteins and pigments

Pink pigment
* Some pink pigment is produced by plants.
* fade considerably in adults at end of breeding season.

Plant pigment
* are basically simple lipids containing many isoprenoid units.
* exist in a wide variety of forms, some with highly complex and large structures.
* have different functions.
* play a very important role in the autumnal coloration of leaves.

### substance | pigment:

Porphyrin
* absorb visible light strongly.
* are an important component of enzymes, such as the hemoglobin that renders our blood red
  - at the core of many biologically important chemical reactions
  - cyclic tetrapyrroles of tremendous importance in biology and chemistry
  - dyes which react with light to close abnormal blood vessels
  - fascinating compounds with biological significance
  - important in making the red blood cells and carrying oxygen throughout the body
  - one of the precursors of heme
  - organic ring compounds like haeme , the pigment in red blood cells
  - pigments found in both animal and plant life
  - red and green pigments that are produced by cells in the feather follicle
  - stable, ring-shaped molecules with a strictly planar structure
  - the conjugate acids of ligands that bind metals to form complexes
* fluoresce under UV light, a trait that readily differentiates it from blood.
* have intense absorption maxima in the visible region.
* is pigment
* then accumulate to high levels, making the weeds fatally hypersensitive to light
  - build up in the body
+ Abelsonite: Minerals

Pure pigment
* Most pure pigment absorbs blue light
  - red light
  - reflects light
* allows very little white light to escape, producing a highly saturated color.

Red pigment
* All red pigments lift off more than other pigments.
* Most red pigment absorbs green light
* Some red pigment absorbs heat
  - has effects
* reflects quality of diet.

Respiratory pigment
* Some respiratory pigment includes hemoglobins.
* increase the oxygen-carrying capacity of the blood.

Rhodopsin
* absorbs and reacts to light entering the eye and begins the visual process.
* works best in dim light.

White pigment
* All white pigments have positive and negative characteristics.
* absorbs none of the colored rays, and black absorbs all of the colors of the spectrum.
* show almost no drying shift in watercolors.

Yellow pigment
* Most yellow pigment absorbs blue light
* Some yellow pigment has effects
  - irritant effects
* is absent in the agouti band of some hairs.
* range from yellow to brown.
* tends to fade.

Piperine
* are alkaloids
  - chemical compounds
* chemical found in black peppers.
* component of black pepper which causes sneezing.
* has a long history of use in some types of traditional medicine.
* is extracted from black pepper using dichloromethane.
* offers the extra benefit of assisting the body in nutrient absorption.
* potent inhibitor of drug metabolism.