Answer the following question given this paragraph: The smallest particle of an element that still has the properties of that element is an atom. Atoms are extremely tiny. They can be observed only with an electron microscope. They are commonly represented by models, like the one Figure below . An atom has a central nucleus that is positive in charge. The nucleus is surrounded by negatively charged particles called electrons. Q: What is the smallest particle of an element that still has the properties of that element is called? Choices: - nucleus - neutron - proton - atom A:
atom
Answer the following question given this paragraph: 6O 2 + C 6 H 12 O 6 6CO 2 + 6H 2 O Photosynthesis produces oxygen as a byproduct, and respiration produces carbon dioxide as a byproduct. In nature, there is no such thing as waste. Every single atom of matter is conserved, recycling indefinitely. Substances change form or move from one type of molecule to another, but never disappear (Figure 5.18). CO2 is no more a form of waste produced by respiration than oxygen is a waste product of photosynthesis. Both are byproducts of reactions that move on to other reactions. Photosynthesis absorbs energy to build carbohydrates in chloroplasts, and aerobic cellular respiration releases energy by using oxygen to break down carbohydrates. Both organelles use electron transport chains to generate the energy necessary to drive other reactions. Photosynthesis and cellular respiration function in a biological cycle, allowing organisms to access life-sustaining energy that originates millions of miles away in a star. Q: Photosynthesis produces oxygen as a byproduct, and respiration produces what as a byproduct? Choices: - carbon monoxide - nitrogen - ozone - carbon dioxide A:
carbon dioxide
Q: Answer the following question given this paragraph: Tundra is found near the poles and up on high mountains. Q: What kind of biome or climate might you find very close to the earth's poles, as well as up on high mountains? Choices: - tropical - desert - taiga - tundra A:
A: tundra
Question: Answer the following question given this paragraph: Ribosomes are cellular substructures where proteins are synthesized. They contain about 65% rRNA and 35% protein, held together by numerous noncovalent interactions, such as hydrogen bonding, in an overall structure consisting of two globular particles of unequal size. Molecules of tRNA, which bring amino acids (one at a time) to the ribosomes for the construction of proteins, differ from one another in the kinds of amino acid each is specifically designed to carry. A set of three nucleotides, known as a codon, on the mRNA determines which kind of tRNA will add its amino acid to the growing chain. (For more information on sequences, see Section 19.4 "Protein Synthesis and the Genetic Code". ) Each of the 20 amino acids found in proteins has at least one corresponding kind of tRNA, and most amino acids have more than one. The two-dimensional structure of a tRNA molecule has three distinctive loops, reminiscent of a cloverleaf (Figure 19.11 "Transfer RNA"). On one loop is a sequence of three nucleotides that varies for each kind of tRNA. This triplet, called the anticodon, is complementary to and pairs with the codon on the mRNA. At the opposite end of the molecule is the acceptor stem, where the amino acid is attached. Figure 19.11 Transfer RNA Saylor URL: http://www. saylor. org/books. Q: Ribosomes are cellular substructures where what are synthesized? Choices: - Molecule - cells - acids - proteins A:
Answer: proteins
*Question*
Answer the following question given this paragraph: Oil is a thick, dark brown or black liquid. It is found in rock layers of the Earth's crust. Oil is currently the most commonly used source of energy in the world. Q: What is the most commonly used source of energy in the world? Choices: - electricity - wind - water - oil A:
**Answer**
oil
*Question*
Answer the following question given this paragraph: Enzymes Enzymes, catalysts that occur naturally in living organisms, are almost all protein molecules with typical molecular masses of 20,000100,000 amu. Some are homogeneous catalysts that react in aqueous solution within a cellular compartment of an organism. Others are heterogeneous catalysts embedded within the membranes that separate cells and cellular compartments from their surroundings. The reactant in an enzyme-catalyzed reaction is called a substrate. Because enzymes can increase reaction rates by enormous factors (up to 10 17 times the uncatalyzed rate) and tend to be very specific, typically producing only a single product in quantitative yield, they are the focus of active research. At the same time, enzymes are usually expensive to obtain, they often cease functioning at temperatures greater than 37C, have limited stability in solution, and have such high specificity that they are confined to turning one particular set of reactants into one particular product. This means that separate processes using different enzymes must be developed for chemically similar reactions, which is time-consuming and expensive. Thus far, enzymes have found only limited industrial applications, although they are used as ingredients in laundry detergents, contact lens cleaners, and meat tenderizers. The enzymes in these applications tend to be proteases, which are able to cleave the amide bonds that hold amino acids together in proteins. Meat tenderizers, for example, contain a protease called papain, which is isolated from papaya juice. It cleaves some of the long, fibrous protein molecules that make inexpensive cuts of beef tough, producing a piece of meat that is more tender. Some insects, like the bombadier beetle, carry an enzyme capable of catalyzing the decomposition of hydrogen peroxide to water (Figure 14.28 "A Catalytic Defense Mechanism"). Enzyme inhibitors cause a decrease in the reaction rate of an enzyme-catalyzed reaction by binding to a specific portion of an enzyme and thus slowing or preventing a... Q: What are the catalysts that occur naturally in living organisms and are primarily protein molecules? Choices: - carbohydrates - hormones - acids - enzymes A:
**Answer**
enzymes