protein study questions

what is each strand of DNA composed of?

4 nucleotides (building blocks of DNA): adenine (A), guanine (G), cytosine (C), and thymine (T) Each of the nucleotides is complementary to (binds to) another nucleotide; A and T are complementary, as are C and G.

what is the last step of protein digestion?

Amino acids then travel via the portal vein to the liver for use in protein synthesis, energy needs, conversion to carbohydrate or fat, or release into the bloodstream for transport to other cells.

what are the nonessential amino acids?

alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, tyrosine

how is RDA calculated?

amount of weight in kilograms times 0.8

15.Which of the following nutrients would most likely be low in a vegan diet? a.vitamin C b.thiamin c.vitamin B-12 d.dietary fiber

b-12

6.Which of the following is a rich source of protein? a.citrus fruits b.dark, leafy greens c.enriched grains d.barbequed chicken

barbequed chicken

Why can't essential acids be synthesized in the body?

because body cells cannot make the carbon skeleton of the amino acid, cannot attach an amino group to the carbon skeleton, or cannot do the whole process fast enough to meet the body's needs.

How are the amino acids in a protein linked together?

by peptide bonds

13.Which of the following is associated with excessive protein intakes? a.dehydration b.anemia c.diarrhea d.diabetes

dehydration

alteration of a protein's 3 dimensional structure is called what and occurs by what?

denaturation of a protein happens by exposure to heat, acid or alkaline solutions, enzymes or agitation

12.Which of the following is not a usual characteristic of marasmus? a.edema b.severe weight loss c.impaired growth d.muscle wasting

edema

4.Which of the following is classified as a complete protein? a.kidney beans b.fat-free milk c.whole-grain bread d.corn tortillas

fat free milk

the release of pepsin is controled by what hormone?

gastrin, is released whenever we think about food or chew food

what are the essential amino acids?

histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine

where does protein synthesis take place?

in the ribosomes, which are located in the cytosol of the cell

where does protein digestion begin?

in the stomach with hydrochloric acid, Once proteins are denatured by stomach acid, pepsin, a major enzyme produced by the stomach, begins to break the long polypeptide chains into shorter chains of amino acids through hydrolysis reactions

how is a food's BV determined?

nitrogen retention in the body is compared with the nitrogen content of the food protein

5.The sequential order of amino acids in a polypeptide chain is called the . a.primary structure b.secondary structure c.tertiary structure d.quaternary structure

primary structure

9.Proteins are involved in all of the following functions except . a.providing energy b.aiding in immune c.promoting bowel health d.providing cell structure function

promoting bowel health

what hormones in the small intestine does chyme trigger?

secretin and cholecystokinin (CKK)

what does secretin and CKK stimulate in the small intestine?

stimulate the pancreas to release the protease or protein-splitting enzymes trypsin, chymotrypsin, and carboxypeptidase into the small intestine. Together, these enzymes digest the polypeptides into short peptides and amino acids that are actively absorbed into the cells of the small intestine

what is the RDA for protein for most individuals?

the RDA for protein is 0.8 g/kg body weight. The recommended percentage of energy that should come from protein is 10 to 35%

how is a chemical score determined?

the amount of each essential amino acid in a gram of the food protein being tested is divided by the "ideal" amount for that amino acid in a gram of the reference protein (usually egg protein). The lowest (limiting) amino acid ratio that is calculated for the essential amino acids of the test protein is the chemical score of that protein. Chemical scores range from 0 to 1.0.

protein quality is determined primarily by what?

the food's digestibility (amount of amino acids absorbed) and amino acid composition compared with a reference protein (e.g., egg white protein) that provides the essential amino acids in amounts needed to support growth

what part of the amino acid makes it unique(determines its structure)?

the side chain

2.A process involved in the synthesis of nonessential amino acids is called . a.ketogenesis b.gluconeogenesis c.transamination d.supplementation

transamination

1.Essential amino acids must be supplied by the diet because the body cannot synthesize them in adequate amounts. a.true b.false

true

11.Many children with kwashiorkor maintain some muscle and subcutaneous fat. a.true b.false

true

3.The carbon skeleton of an amino acid is the portion remaining after an amino group has been removed. a.true b.false

true

8.Hospitalized patients recovering from illness or trauma usually need additional protein to attain positive nitrogen balance. a.true b.false

true

what is the most widely used measure of protein quality?

Protein Digestibility Corrected Amino Acid Score (PDCAAS)

how is a food's protein efficiency ratio (PER) determined?

The PER compares the amount of weight gain by a growing laboratory animal consuming a standardized amount of the protein being studied with the weight gain by an animal consuming a standardized amount of a reference protein, such as casein (milk protein)

How is PDCAAS determined?

This score is derived by multiplying a food's chemical score by its digestibility

what are amino acids composed of?

a central carbon bonded to 4 groups of elements: a nitrogen (amino) group, an acid (carboxyl) group, hydrogen, and a side chain (often signified by the letter R)