Topic 5 Protein

Question 0

Functions of proteins. What is protein sparing?

Answer 0

Providing adequate energy from cho & fat so protein can do its job.

E.g. Gym/toning/building muscle
Oatmeal/milk
Depends on carbs & fats for energy, so the protein can help build the muscles or it will use the protein for energy.

Question 1

What are proteins?

Answer 1

Large complex molecules composed of amino acids.
Lego amino acids/city make up protein
Contain carbon, hydrogen, oxygen, nitrogen
Primary source of nitrogen in our diets from proteins
20 different amino acids are used to make proteins

Question 2

Functions of proteins (know 2)

Answer 2

Cell growth, repair, & maintenance
Enzymes
Component of hair & nails

Question 3

What are the 2 groups of Amino acids?

Answer 3

Essential amino acids (total of 9)
Cannot be produced by our bodies
Must be obtained from food ( need it but body doesn’t make it)

Nonessential amino acids (total of 11)
Can be made by our bodies
Made by transferring amino groups

Question 4

How are proteins made?

Answer 4

Proteins are long chains of amino acids

Amino acids are joined to each other by peptide bonds.

Question 5

What are the 3 types of peptides?

Answer 5

Dipeptide aa+aa (2)
Tripeptide aa+aa+aa (3)
Polypeptide many aa

Question 6

What are good sources of protein?

Answer 6

Animal sources
Meat, poultry, fish & seafood, eggs, milk & dairy, cheese

Plant sources
Legumes, nuts, rice, pasta, grains, seeds, soy, tofu

Question 7

What are high quality proteins?

Answer 7

Animal sources
Meat & alternative group
Milk & alternative group

Question 8

What is an incomplete protein?

Answer 8

Lacks one or more essential amino acids
Not sufficient for growth/health
Considered a low quality protein e.g. Plant proteins
Banana carrots rice

Question 9

What is a complete protein?

Answer 9

Contains sufficient amounts of all 9 essential amino acids.
Considered a high quality protein
E.g. Animal proteins and soy chicken

Question 10

What are complementary proteins?

Answer 10

2 or more proteins whose amino acid assortments complement each other in such a way that the essential amino acids missing from one are supplied by the other. Also called mutual supplementation
E.g. Rice & beans peanut butter & toast barley & lentil soup

1 doesn’t have something that the other has together they are complete amino acids to make a complementary protein

Question 11

What are the 2 factors that determine protein quality?

Answer 11

Amount of essential amino acids

Protein digestibility
Animal foods are highly digestibility
Soy foods are highly digestibility
Other plant foods are less digestible

Question 12

What is the gold standard food item in terms of protein quality is..

Answer 12

Egg whites

Question 13

What is protein denaturation?

Answer 13

Altering shape or stability of the protein

Destroying the protein/changing

Question 14

What 3 things are denaturation caused by?

Answer 14

Heat cooking
Acid stomach juices when you eat it
Force whipping egg whites

Question 15

Why is denaturation important?

Answer 15

It’s important to the digestion of food protein

Stomach acids open up a protein’s structure- allows digestive enzymes to make contact w/ the peptide bonds and cleave them

Question 16

What are potential risks of too much protein?

Answer 16

High cholesterol
Bone loss
Kidney disease