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