Chapter 7.1: Proteins #1

Animal proteins contain all of the essential amino acids

true

Essential amino acids are obtained from diet while nonessential amino acids can be produced by the body

true

Excess protein intake is stored as fat

true

Denaturation

a change in the structure of a protein, resulting in an unfolded polypeptide chain that usually lacks biological activity

Vegetarians must consume complementary proteins at the same meal to obtain all of the essential amino acids

false

A well-planned plant-based diet will generally provide high-quality protein

true

Gout is more common in men than women

true

Which of the following is a conditional amino acid?

tyrosine

Which of the following lists of amino acids contain all essential amino acids?

valine, threonine, lysine, methionine

The RDA for protein is based on an individual's:

weight

Excellent sources of plant proteins include all of the following except:

corn

Proteases

enzymes that break down protein into peptides and amino acids

Muscle building depends on extra protein

false

Proteins that are altered on exposure to acid or alkaline substances, heat, or agitation are said to be _______

Denatured

Protein turnover

the constant synthesis and breakdown of proteins in the body

There are _____ nonessential amino acids

11

In Africa and East Asia, about ______ percent of the protein eaten comes from animal sources

20

Worldwide, approximately _____ percent of protein in the diet comes from animals

35

There are _____ conditionally essential amino acids

6

Approximately ______ percent of protein in the American diet comes from animals

70

pH

A scale, ranging 0-14, that measures the acidity or alkalinity of a substance; acids have a pH lower than 7, and bases have a pH higher than 7. The lower the pH, the stronger the acid, while the higher the pH, the stronger the base

The building blocks for protein are called:

amino acids

Nonessential Amino Acids

amino acids that the body can make if supplied with adequate amounts of nitrogen; they do not need to be supplied in the diet

Essential Amino Acids

amino acids that the body cannot make at all or cannot make enough of to meet physiological needs; they must be supplied in the diet

A carbon skeleton is left when the _____ -containing group is removed

nitrogen

Conditionally essential amino acids

nonessential amino acids that become essential under certain circumstances, such as during illness

Amino acid pool

the amino acids in body tissues and fluid that are available for new protein synthesis

Incomplete (low-quality) proteins

proteins that lack one or more amino acids

Complete (high-quality) proteins

proteins that supply all of the essential amino acids in the proportions the body needs

Which of the following is a nonessential acid?

serine

The plant source of protein that is considered a complete protein is:

soybeans

There are ______ essential amino acids

9

Complementary Protein

an incomplete food protein whose assortment of amino acids makes up for, or complements, another food protein's lack of specific essential amino acids; the combination of the two proteins provides sufficient amounts of all the essential amino acids