Week 4

Question 1

What are organic substances containing amino and carbonyl groups?

Answer 1

Amino acids

Exist as L- and D-isomers
Every amino acid has a side chick, a carboxyl group, and an amino group

Question 2

Protein digestion begins in the

Answer 2

stomach

Parietal cells secrete HCl
Chief cells secrete pepsinogen

HCl converts pepsinogen into pepsin

Pepsin breaks the peptide bond into proteins and converts them into smaller proteins (peptides)

Question 3

___ is preferred major fuel for rapidly dividing cells, including enterocytes, lymphocytes, macrophages, and tumors

Answer 3

Glutamine

Question 4

AA that are inadequately synthesized de novo by the body relative to needs and which must be provided by the diet

Answer 4

Essential AA

Question 5

AA that normally can be synthesized in adequate amounts by the organism, but which must be provided from the diet to meet optimal needs under conditions where rates of utilization (reproduction/disease prevention/injuries/burns) are greater than rates of synthesis (e.g., glutamine, proline, cysteine, tyrosine).

Answer 5

Conditionally essential AA

Question 6

AA that can be

synthesized de novo in adequate amounts by the body to meet optimal requirements.

Answer 6

Non-essential AA

Question 7

some AA are important regulators of key metabolic pathways that are necessary for maintenance, growth, reproduction, and immunity in organisms, therefore maximizing efficiency of food utilization, enhancing protein accretion, reducing adiposity, and improving health.

Answer 7

Functional AA

Question 8

What AA are precursors of epinephrine, norepi, dopamine, thyroid hormones?

Answer 8

Tyrosine

Phenylalanine

Question 9

What is the major antioxidant in cells and regulates homeostasis of free radicals?

Answer 9

Glutathione

Question 10

Glutathione is formed from

Answer 10

Cysteine
Glutamate
Glycine

Question 11

How does protein deficiency impair the immune function?

Answer 11

Glutamine, arginine, methionine, and cysteine enhance the immune system by:

• mTOR activation (mTOR is a protein that regulates cell growth, motility, survival)
• NO and glutathione synthesis (NO is cytotoxic to bacteria and viruses; glutathione serves as an antioxidant)
• H2S signaling (endogenously produces; serves a signal in cardiovascular, immune, endocrine systems)

Also, end products of tryptophan and proline metabolism are needed for proper immune functioning

Question 12

___-deficient diets contribute to decrease sperm counts

Answer 12

Arginine

Involved in spermatogenesis and sperm viability

Question 13

Dietary supplementation with ___ or ___ reduce plasma levels of glucose and homocysteine

Answer 13

Arginine

Watermelon (citrulline)

Question 14

__ reduces fat mass

Answer 14

Arginine

Question 15

___ reduces fat accretion and promotes protein deposition

Answer 15

Arginine