Gradpoint Quarter 4 Chemistry Amino Acids and Their Polymers

What is the role of an enzyme?

Speeds up Biochemical reactions

What is a protein? A. A Polypeptide with simple sugars incorporated into the molecule B. A polypeptide with more than 100 amino acids *C. A polypeptide with between 10 to 100 Amino acids D. A polymer of simple sugars and amino acids

A. Polypeptide with more than 100 amino acids

Why are the amino acid sequences His—Gly—Ala and Ala—Gly—His chemically different from each other A. The free amino group and carboxylic acid group are located on different amino acids. B. One sequence is a tripeptide; the other sequence is a triglyceride. C. The two sequences are composed of different atoms and have different molar masses.

A. The free amino group and carboxylic acid group are located on different amino acids.

Which best describes the shape of myoglobin, which in many ways is a typical protein? *A. a complex three-dimensional shape formed from many twisted helixes B. A cylindrical shape that forms from a single twisted helix C. A straight chain, like beads on a straight piece of string D. A highly-branched chain, much like the branches of a maple tree

A. a complex three-dimensional shape formed from many twisted helixes

Which is generally true of enzymes in cells? A.Enzymes allow reactions to proceed at body temperature X B. Enzymes require co-enzymes to be effective. X C. Enzymes are changed by the reaction they catalyze

A.Enzymes allow reactions to proceed at body temperature

What is the active site of an enzyme? A.The place where the substrate binds X B. Either end of the polypeptide that forms enzyme X C. The outer surface of the enzyme's three-dimensional structure

A.The place where the substrate binds

As a general rule, how many specific substrates can bind to an enzyme? A. 2 *B. 1 C. About 100 D. 20

B. 1

When two amino acids join together with a peptide bond, what functional group is formed? A. Ether *B. Amide C. Ester D. Carboxylic Acid

B. Amide

A peptide bond is a bond between which functional groups? A. Carboxyl and Alcohol *B. Amino and Carboxyl C. Amino and Alcohol D. Carbonyl and Carbonyl

B. Amino and Carboxyl

In the human body, the cations of magnesium, iron, potassium, and zinc act as_____ to help speed up reactions. A. Inorganic catalysts *B. Coenzymes C. Enzyme Substitues D. Enzymes

B. Coenzymes

In which part of plants or animals are proteins especially common? A. Tough plant tissues, such as wood B. Skin, hair, nails, and muscle C. The soft fleshy parts of fruits D Tissues that store fat

B. Skin, hair, nails, and muscle

How many common amino acids are formed and used by living organisms ? A. About 100 B. 52 *C. 20 D. 4

C. 20

Enzymes are proteins that act as ____ for biological reactions. A. Reactants B. Substitutes *C. Catalysts D. Energy Sources

C. Catalysts

Differences between amino acids are normally due to differences in which part of the molecule? A. amino group B. carboxyl group C. central carbon D. side chain

D. Side Chain