Chapter 6 Smartbook

The population most vulnerable to sickle cell anemia in North America is people of ______.

African descent

How does denaturation of a protein affect its function?

The protein loses its normal biological activity.

Which of the following are examples of branched-chain amino acids?

Valine Isoleucine Leucine

As a proportion of total protein intake, essential amino acid requirements of an infant are ______ those of an adult.

higher than

An amino acid that can be synthesized by a healthy body in sufficient amounts is considered

nonessential

Which type of amino acid can be synthesized by the human body?

nonessential (dispensable) amino acids

Plant proteins are a heart-healthy alternative to animal proteins because they typically contain less or no ______ than animal sources of protein.

saturated fat phytochemicals

Pepsin can break a polypeptide chain into ______.

shorter chains of amino acids

The body links amino acids with peptide bonds in order to form

proteins

The amino acid patterns in plant proteins are ______ from human proteins.

quite different

Which of the following are functions of protein?

-blood clotting -production of enzymes and hormones -fluid balance

Leucine, isoleucine, and valine are examples of

-essential amino acids, -branched-chain amino acids

Inadequate intake of essential amino acids may lead to

-slow production of body proteins. -impaired growth. -muscle wasting.

There are ______ nonessential amino acids.

11

The typical diet provides about ______ percent of protein as essential amino acids, when only 11 percent is required.

50

How many amino acids are considered essential?

9

What is the term used for the building blocks of proteins?

Amino acids

Proteins serve which of the following functions?

Building block for muscles and bone Synthesis of enzymes and hormones Maintenance of fluid balance Aid in blood clotting

Which of the following elements can be found in amino acids?

Carbon Hydrogen Oxygen Nitrogen

Incorrect mRNA production and incorrect polypeptide chain production both result from an error in the ___________ code.

DNA

The nucleus is the storage site for ______ in the cell.

DNA

Lentils (a type of legume) supply ample amounts of all nine essential amino acids.

False

Protein synthesis takes place in the nucleus.

False

Which of the following are the two primary sources of fuel for cells?

Fats Carbohydrates

Which of the following are true statements about the functions of protein?

Proteins provide structure for bones. Protein supports immune function. Protein is necessary for fluid balance.

How do proteins contribute to acid-base balance of the blood?

Serve as buffers that resist changes in pH Pump ions into and out of cells

Which statements are true about nuts and seeds?

Some, such as chia and pumpkin seeds, are also a good source of amino acids. They should be consumed in moderation. They are a dense source of calories.

Adults need only about 11% of their total protein requirement to be supplied by essential amino acids.

True

Amino acids serve as a source of nitrogen for the human body.

True

If adequate amounts of essential amino acids are not consumed, a person's health will deteriorate.

True

Proteins serve in the regulation and maintenance of the human body by aiding in blood clotting, fluid balance, and visual processes.

True

Which of the following are potential causes of denaturation?

agitation exposure to acid exposure to heat

Complementary proteins are two incomplete sources of protein that together provide

all nine essential fatty acids

In extreme starvation, _____ from muscle tissue start to be converted to glucose, which wastes muscle and produces edema.

amino acids

Lower-quality (incomplete) proteins are dietary proteins that are low in, or lack, one or more essential

amino acids

Proteins are made up of one or more long chains of __.

amino acids

Sickle cell disease occurs when _____ are out of order on a protein.

amino acids

What helps to maintain body fluid balance?

blood proteins

The purpose of transfer RNA (tRNA) is to ______.

bring specific amino acids to the ribosomes for protein synthesis

What is it called when two sources of protein combine to form a complete protein, whereas by themselves, they supply an inadequate amount of essential amino acids?

complementary protein

When an egg is heated in a frying pan, the three-dimensional shape of the proteins in the egg white is altered, such that the egg white changes from a clear liquid to a white solid. This is an example of ______ of proteins.

denaturation

Stomach acid and heat can ______ a protein, changing its shape and altering its biological activity.

denature

______ involves a buildup of excess fluid in tissues.

edema

Indispensable amino acid is another term for a(n)

essential amino acid

Which of the following cannot be synthesized by humans in sufficient amounts and must be included in the diet?

essential amino acid

Amino acids are formed exclusively of carbon and hydrogen.

false

Most enzymes are lipids.

false

Proteins do not supply the body with energy.

false

The presence of proteins in the blood causes edema.

false

The protein needs of an infant and preschool age child are the same as an adult's.

false

tRNA is responsible for transferring DNA from the cell's nucleus to the cytoplasm.

false

In most circumstances, in what form are proteins absorbed from the GI tract into the bloodstream?

individual amino acids

A(n) ______ amino acid is the essential amino acid in lowest concentration in a food or diet relative to body needs and limits the amount of protein a body can synthesize.

limiting

The essential amino acid in lowest concentration in a food or diet relative to body needs is the

limiting amino acid

Increasing ______ intake has the greatest potential to provide satiety and improve appetite control.

protein

Which macronutrient is crucial to the regulation and maintenance of the body?

protein