A.AS #2

Question 1

What are essential amino acids?

Answer 1

Amino acids that can’t be synthesized by the body.

Must be supplied in the diet (e.g., Phe, Trp, Val, Leu, Ile, etc.).

Question 2

What are semi-essential amino acids?

Answer 2

Amino acids synthesized but insufficient during high demand.

Examples: Arg, Cys during growth, illness, or pregnancy.

Question 3

What are non-essential amino acids?

Answer 3

Amino acids synthesized sufficiently by the body.

Examples: Glu, Asp, Ala, Pro, Ser, etc.

Question 4

Which amino acids are purely ketogenic?

Answer 4

Lysine and Leucine.

Produce only ketone bodies.

Question 5

What are glucogenic and ketogenic amino acids?

Answer 5

Amino acids that produce both glucose and ketone bodies.

Examples: Trp, Ile, aromatic AAs.

Question 6

What is the function of pepsin in protein digestion?

Answer 6

Breaks down proteins into smaller peptides.

Activated in the stomach by HCl.

Question 7

What enzymes are secreted by the pancreas for protein digestion?

Answer 7

Trypsin, chymotrypsin, elastase, carboxypeptidase.

Activated in the small intestine.

Question 8

What is acute pancreatitis?

Answer 8

A condition where pancreatic enzymes activate prematurely.

Damages pancreatic tissue and can be fatal.

Question 9

How are amino acids absorbed in the intestine?

Answer 9

By sodium-dependent active transport and diffusion.

Small neutral and aromatic AAs use specific transporters.

Question 10

What is the gamma-glutamyl cycle’s role in amino acid transport?

Answer 10

Facilitates absorption of amino acids using glutathione.

Requires ATP and glutathione.

Question 11

What are the main sources of free amino acids in the body?

Answer 11

Diet, body synthesis, and protein degradation.

Maintain the amino acid pool for various uses.

Question 12

What is the largest use of the amino acid pool?

Answer 12

Protein synthesis in the body.

Also used for synthesizing compounds like GABA, histamine, etc.

Question 13

What is histamine synthesized from?

Answer 13

Histidine by decarboxylation.

Question 14

What are histamine blockers used for?

Answer 14

To treat allergies and acid reflux.

Examples: Diphenhydramine (allergy), Cimetidine (acid reflux).

Question 15

What is nitric oxide synthesized from?

Answer 15

Arginine.

Question 16

What is the function of nitric oxide (NO)?

Answer 16

Acts as a signaling molecule in the body.

Regulates vasodilation, neurotransmission, and blood clotting.

Question 17

What are the neurotransmitters derived from tyrosine?

Answer 17

Dopamine, epinephrine, norepinephrine, and thyroxine.

Question 18

What is the cause of maple syrup urine disease?

Answer 18

Defect in branched-chain ketoacid dehydrogenase.

Leads to accumulation of Val, Leu, Ile and metabolic acidosis.

Question 19

What is the main symptom of albinism?

Answer 19

Lack of melanin synthesis.

Caused by a defect in tyrosinase or tyrosine-3-monooxygenase.

Question 20

What is homocystinuria caused by?

Answer 20

Deficiency of cystathionine beta-synthase.

Results in high homocysteine and methionine, low cysteine levels.

Question 21

What is the defect in phenylketonuria (PKU)?

Answer 21

Phenylalanine hydroxylase deficiency.

Causes phenylalanine accumulation; managed by dietary restriction.

Question 22

What is the function of GABA?

Answer 22

Acts as an inhibitory neurotransmitter.

Question 23

What are the nitrogen derivatives of glycine?

Answer 23

Heme, purines, creatine.

Question 24

What enzyme is deficient in alkaptonuria?

Answer 24

Homogentisate-1,2-dioxygenase.

Leads to dark urine and ochronosis (pigment accumulation).

Question 25

What are the symptoms of methylmalonic acidemia?

Answer 25

Metabolic acidosis, lethargy, and failure to thrive.

Caused by defect in methylmalonyl-CoA mutase.

Question 26

What is the treatment for homocystinuria?

Answer 26

Methionine restriction and vitamin B6/folate supplementation.

Aims to reduce homocysteine levels.

Question 27

What is histamine synthesized from?

Answer 27

Histidine by decarboxylation.

Question 28

What are histamine blockers used for?

Answer 28

To treat allergies and acid reflux.

Examples: Diphenhydramine (allergy), Cimetidine (acid reflux).

Question 29

What is nitric oxide synthesized from?

Answer 29

Arginine.

Question 30

What is the function of nitric oxide (NO)?

Answer 30

Acts as a signaling molecule in the body.

Regulates vasodilation, neurotransmission, and blood clotting.

Question 31

What are the neurotransmitters derived from tyrosine?

Answer 31

Dopamine, epinephrine, norepinephrine, and thyroxine.

Question 32

What is the cause of maple syrup urine disease?

Answer 32

Defect in branched-chain ketoacid dehydrogenase.

Leads to accumulation of Val, Leu, Ile and metabolic acidosis.

Question 33

What is the main symptom of albinism?

Answer 33

Lack of melanin synthesis.

Caused by a defect in tyrosinase or tyrosine-3-monooxygenase.

Question 34

What is homocystinuria caused by?

Answer 34

Deficiency of cystathionine beta-synthase.

Results in high homocysteine and methionine, low cysteine levels.

Question 35

What is the defect in phenylketonuria (PKU)?

Answer 35

Phenylalanine hydroxylase deficiency.

Causes phenylalanine accumulation; managed by dietary restriction.

Question 36

What is the function of GABA?

Answer 36

Acts as an inhibitory neurotransmitter.

Question 37

What are the nitrogen derivatives of glycine?

Answer 37

Heme, purines, creatine.

Question 38

What enzyme is deficient in alkaptonuria?

Answer 38

Homogentisate-1,2-dioxygenase.

Leads to dark urine and ochronosis (pigment accumulation).

Question 39

What are the symptoms of methylmalonic acidemia?

Answer 39

Metabolic acidosis, lethargy, and failure to thrive.

Caused by defect in methylmalonyl-CoA mutase.

Question 40

What is the treatment for homocystinuria?

Answer 40

Methionine restriction and vitamin B6/folate supplementation.

Aims to reduce homocysteine levels.