Protein digestion/absorption and within the diet.

Question 1

Where does protein digestion occur?

Answer 1

NOT IN MOUTH

1. Stomach
2. Proteases and proenzymes
   - Pepsin from pepsinogen
3. Small Intestine

Question 2

Protein breakdown in stomach?

Answer 2

• Proteins are denatured by hydrochloric acid
• Pepsin begins digestion
• 10–20% of digestion

Question 3

Where does Undigested protein go?

Answer 3

-Feces

Question 4

Problems with digestion

Answer 4

1. Celiac disease (Gluten from wheat, rye and barley)

2. Cystic fibrosis

Question 5

Is pepsinagin active or inactive?

Answer 5

Inactive

Question 6

Protein digestion in small intestine?

Answer 6

Proteases and intestinal lining cells

Question 7

Where are Amino acids and peptide absorbed?

Answer 7

Small intestine

Question 8

What are Pancreatic Proteases?*

Answer 8

Arginine + lysine+ Phenylalanine + Tyrosine

Specific to individual bonds. Made in pancreas- used in small intestine.

Question 9

What is the first step of pepsin when digesting proteins?

Answer 9

1. break down the chains of amino acids
2. Trypsin breaks the bonds of arginine and lysine.
3. Chymotrypsin breaks the bond of Phenylalanine and tyrosine.

Question 10

Carboxpeptidase?*

Answer 10

Phenylalanine + Arginine+ Lysine+ tyrosine

ability to clean off/slip off the terminal Amino Acids

Question 11

Dipeptidase?*

Answer 11

Arginine+ lysine+ phenylalanine

comes from small intestine

Question 12

Tyrosine is connected to?*

Answer 12

Arginine

Question 13

Chymotrypsin is connected?*

Answer 13

Phenylalanine

Question 14

Protein synthesis

Answer 14

-Directed by cellular DNA
Amino Acid assembled in specific sequence
Draws on Amino Acid pool as needed

Question 15

Synthesis of nonprotein molecules

Answer 15

Precursors:

• Neurotransmitters
• Vitamins (niacin (nonessential)
• DNA
• RNA
• melanin
• histamine
• glucose

Question 16

Protein turnover?

Answer 16

Constant recycling of protein

Question 17

Amino Acid Pool?

Answer 17

Available AA:

-Protein synthesis; produce energy and glucose

Question 18

Protein and nitrogen excretion in the body?

Answer 18

Breakdown of amino acids:

• Removes nitrogen (amino) group
• Converts amino group to ammonia
• Ammonia to liver for conversion to urea
• Urea excretion via urine

Goes from liver ->urea -> excreted through urine.

Question 19

Nitrogen balance

Answer 19

Nitrogen intake vs. nitrogen output

Question 20

Nitrogen equilibrium

Answer 20

Nitrogen intake = nitrogen output

-Healthy grown adults

Question 21

Positive nitrogen balance

Answer 21

Nitrogen intake > nitrogen output

Growth; recovery from illness

Question 22

Negative nitrogen balance

Answer 22

Nitrogen input is less then Nitrogen Output

ACUTE Injury + Illness

Question 23

T/F: During the acute phases of injury and illness you are in the first phases of negative nitrogen balance.

Answer 23

TRUE

Question 24

T/F: During recovery you want to be in a Negative nitrogen balance.

Answer 24

FALSE a positive nitrogen balance

Question 25

Recommended protein intake for adults?

Answer 25

0.8 gram per kilogram body weight

Question 26

Recommended protein intake for infants?

Answer 26

1.5 grams per kilogram body weight

Question 27

Physical Stress

Answer 27

Infection, burns, fevers, surgery, and intensive weight training

Question 28

Recommended protein intake for elderly?

Answer 28

1.0 grams per kg body weight.

Question 29

T/F: Consumption in the United States;

Generally protein intake > protein needs

Answer 29

TRUE

Question 30

Complete Proteins?

Answer 30

Supply all indispensable amino acids

Animal proteins; soy proteins

Question 31

Incomplete Proteins?

Answer 31

Missing one or more indispensable amino acids
Most plant proteins
Two incomplete proteins = one complete

Question 32

Complimentary Proteins?

Answer 32

Beans and rice. Together they give you all of the indespensible AA.

Question 33

Evaluating protein quality has to have what?

Answer 33

1. Amino acid composition has to be there.
2. Needs to be Digestible
3. Protein Digestibility-Corrected Amino Acid Score (PDCAAS)

Question 34

What is Protein Digestibility-Corrected Amino Acid Score (PDCAAS)?

Answer 34

• Looks at your proteins and what will actually be in your body and bloodstream
• This is Used to determine %DV

Question 35

Protein and Amino Acid additives

Answer 35

Structure, texture, and taste of foods

Question 36

Protein and Amino Acid supplements

Answer 36

Generally not needed
Risks unknown

*Most individuals don’t need protein supplements.
(RARE) Too many of these ill result in kidney failure. *