Chapter 6: Protein: Amino Acid

What element is found in proteins but not in carbohydrates and fats? a. Carbon b. Oxygen c. Calcium d. Nitrogen

In comparison to the composition of carbohydrates and fats, which element found in proteins makes them unique? a. Carbon b. Oxygen c. Nitrogen d. Hydrogen

Which of the following is the primary factor that differentiates one amino acid from another? a. The side group b. The central carbon atom c. The number of oxygen atoms d. the number of nitrogen

Which of the following elements is found in certain amino acids? a. Iron b. Sulfur c. Calcium d. Potassium

Terms used to classify amino acids in the diet include all of the following except a. essential b. nonessential c. partially essential d. conditionally essential

How many different kinds of amino acids make up proteins?

All of the following are contained in an amino acid except? a. an acid group b. an amino group c. an aldehyde group d. a central carbon atom

Approximately how many different amino acids are used in the synthesis of body proteins? a. 5 b. 10 c. 20 d. 35

What is the simplest amino acid? a. valine b. glycine c. alanine d. methionine

Which of the following is not an essential amino acid in human nutrition? a. Proline b. Threonine c. Methionine d. Tryptophan

Any of the following can be used by the body for the synthesis of nonessential amino acid except: a. a fragment of fat b. an essential mineral c. an essential amino acid d. a fragment of carbohydrate

What amino acid is classified as conditionally essential when dietary intake of phenylalanine is insufficient or the body cannot normally metabolize phenylalanine? a. cysteine b. tyrosine c. glutamine d. isoleucine

Which of the following is a feature on an essential amino acid? a. It is not necessary in the diet b. It must be supplied by the diet c. It can be made from fat in the body d. It can be made from glucose in the body

What type of reaction is required to bind two molecules of glycine together and release a molecule of water? a. Hydrolysis b. Deamination c. Denaturation d. Condensation

When two amino acids are chemically joined together, the resulting structure is called a a. dipeptide b. diglyceride c. polypeptide d. disaccharide

What is the composition of a tripeptide?

What is meant by the amino acid sequence of a protein? a. number of side chains in the protein b. folding arrangement of the peptide chain c. order of amino acids in the peptide chain d. order of only the essential amino acids in the protein

A dispensable amino acid is one that a. is not needed by the body b. can be synthesized by the body c. can be used to synthesize an indispensable amino acid d. cannot be synthsized by the body because of a genetic defect

In comparison to the well-defined structure of starch, which of the following is the most important factor that allows for the synthesis of thousands of different proteins? a. number of cell ribosomes b. number of different amino acids c. availability of amino acids containing sulfur d. availability of amino acids containing hydroxyl groups

Which of the following would be classified as a polypeptide? a. 1 amino acid b. 3 amino acids bonded together c. 9 fatty acids bonded together d. 20 amino acids bonded together

The following amino acids are linked together: glycine- lysine- valine. This compound is a a. dipeptide b. tripeptide c. polypeptide d. oligopeptide

The weak electrical attractions within polypeptide chains account for the protein's a. primary structure b. secondary structure c. tertiary structure d. quaternary structure

Which of the following is a feature of hemoglobin? a. It has not tertiary structure b. It holds the mineral calcium c. It is constructed of 4 polypeptide chains d. It has no primary or secondary structure

An example of a protein with quaternary polypeptide structure is a. insulin b. typtophan c. hemoglobin d. disulfide bridges

what is the process by which heat or acidity disrupts the noral shape of the protein chain? a. digestion b. condensation c. denaturation d. hydrogenation

The application of heat or acid to a protein that causes its shape to change is known as a. stiffening b. condensation c. denaturation d. destabilization

What process results in the hardening of an egg when it is exposed to heat? a. solidification b. denaturation c. condensation d. protein interaction

After a hamburger is eaten, in what organ is the hydrolysis of its proteins initiated? a. mouth b. stomach c. small intestines d. large intestines

What is the name of the inactive form of the protein- splitting enzyme in the stomach? a. peptidase b. propepsin c. pepsinogen d. propeptidase

In what organ is pepsin active

What digestive enzyme would be most affected in people who are unable to produce hydrochloric acid? a. pepsin b. transaminase c. pancreatic protease d. intestinal peptidase

Protein-hydrolyzing ensymes are commonly known as a. proteases b. hydrolyzers c. prodigestins d. denaturases