Synthesis of AAs and Their Derivatives --

Question 1

All AAs can be derived from what?

Answer 1

Intermediates of metabolic pathways

Question 2

How many AAs do bacteria and plants synthesize?

Answer 2

All of them

Question 3

How many AAs can mammals synthesize from intermediates of metabolic pathways? Why can’t the rest be synthesized?

Answer 3

10

Missing enzymatic machinery

Question 4

What is the source of amino groups (NH3+)

Answer 4

Glutamate and glutamine

Question 5

How many essential AAs do we need to acquire through diet?

Answer 5

9

Question 6

List the 9 essential AAs:

Answer 6

1. Histidine
2. Isoleucine
3. Leucine
4. Lysine
5. Methionine
6. Phenylalanine
7. Threonone
8. Tryptophan
9. Valine

Question 7

What is a conditionally essential AA?

Answer 7

Required to some degree in young, growing animals, and/or sometimes during illness.

Question 8

How many conditionally essential AAs are there? List them.

Answer 8

1. Arginine
2. Cysteine
3. Glutamine
4. Glycine
5. Proline
6. Tyrosine

Question 9

How many non-essential AAs are there? List them.

Answer 9

1. Alanine
2. Asparagine
3. Aspartate
4. Glutamate
5. Serine

Question 10

What are non-standard AAs? Give 2 examples

Answer 10

Non protein-coding AAs. Not used in protein synthesis.

1. GABA
2. Homocysteine

Question 11

What is the 21st AA? How can it be classified among AAs?

Answer 11

Selenocysteine (selen from selenium).

Standard AA

Question 12

How did humans synthesize selenocysteine? How is this different from all other AAs?

Answer 12

synthesized from cysteine on tRNA. It was built on tRNA.

…compared to all other AAs that are metabolic intermediates.

Question 13

What is selenocystein coded by? What is UGA?

Answer 13

UGA which is a nonsense codon/stop codon (doesn’t code for any AA)

Question 14

What 2 enzymes is selenocystein involved in the synthesis of?

Answer 14

1. Glucose-6-phosphate

2. Glutathione peroxidase

Question 15

What is the 22nd AA? Where is it found?

Answer 15

Pyrrolysine. Only found in bacteria. Utilized in methane produced by bacteria)

Question 16

What is tyrosine derived from?

Answer 16

Phenylalanine in mammals

Question 17

What AAs is alpha-ketoglutarate a precursor of?

Answer 17

Glutamate –>(Glutamine / Proline / Arginine)

Question 18

What AAs is Pyruvate a precursor of?

Answer 18

Alanine / Valine / Leucine / Isoleucine

Question 19

What AAs is 3-phosphoglycerate a precursor of?

Answer 19

Serine –> (Glycine / Cysteine)

Question 20

What AAs is Oxaloacetate a precursor of?

Answer 20

Aspartate –> (Asparagine / Lysine / Methionine / Threonine)

Question 21

What AAs are Phosphoenolpyruvate & Erythrose 4-phosphate precursors of?

Answer 21

(Phenylalanine –> tyrosine)

Tyrosine (C.e)

Tryptophan

Question 22

What AAs is Ribose-5-phosphate a precursor of?

Answer 22

Histidine

Question 23

Is the pentose phosphate pathway important for AA synthesis in mammals?

Answer 23

No, doesn’t contribute to AA synthesis in mammals

Question 24

What AA is used in the production of heme in mammals? In plants/bacteria?

Answer 24

Glycine

Glutamate

Question 25

What metabolic intermediate is combined with glycine/(glutamate) in the 1st step of heme production? What compound does this form?

Answer 25

Succinyl-CoA. Delta-aminolevulinate

Question 26

What happen to the delta-aminolevulinate compounds once they are produced?

Answer 26

8 of them are brought together and form pairs via hydration reactions. 4 pairs then combine to make 4 porphobilinogen which forms a benzene ring structure.

Question 27

What do the 4 protoporphyrin in the benzene ring structure incorporate into their center to form heme?

Answer 27

Iron

Question 28

What does the accumulation of porphyrin intermediates lead to in heme production?

Answer 28

"Porphyria diseases" | Abnormality of enzymes leads to accumulation

Question 29

What is heme called without the iron center?

Answer 29

Protoporphyrin

Question 30

What enzyme interacts with heme once it is released? What does this create? Biproducts?

Answer 30

Heme oxygenase Biliverdin CO2 and Iron released

Question 31

What is biliverdin transformed into afterwards? Enzyme? What is this reaction dependent on?

Answer 31

Bilirubin Biliverdin reductase NADPH

Question 32

What is an important characteristic of bilirubin? How is it transported to the liver?

Answer 32

Hydrophobic. Transported in blood via serum albumin

Question 33

What is bilirubin converted to in the liver? Enzyme?

Answer 33

Bilirubin diglucuronide. Glucuronyl-bilirubin transferase

Question 34

Where is Bilirubin diglucuronide transported to after its stop the liver? What color is bilirubin in the bile?

Answer 34

Intestine (in bile) Now bilirubin Green!

Question 35

What is bilirubin converted to in bile? Via what?

Answer 35

--> Urobilinogen --> Stercobilin via bacteria!!

Question 36

Where can Urobilinogen be transported after it's time in the liver?

Answer 36

Kidney where it is converted to urobiln

Question 37

What color is bilirubin? What does a blue wound indicate? What does a green/yellow wound indicate?

Answer 37

Green Fresh punch. Recovering.

Question 38

What does the accumulation of bilirubin lead to? What enzyme is disfunctional?

Answer 38

Jaundice Glucuronyl-bilirubin transferase

Question 39

What neurotransmitter does tyrosine help create?

Answer 39

Epinephrine. Fight or flight

Question 40

What neurotransmitter does glutamate help create? What is this neurotransmitter needed for? This neurotransmitter send inhibitory signals where?

Answer 40

GABA Muscle tone maintenance Central Nervous System

Question 41

What neurotransmitter does histadine help create? When is this neurotransmitter released? This neurotransmitter stimulates the secretion of what?

Answer 41

Histamine Released during allergic reactions HCl secretion in stomach

Question 42

What do anti-histamine medications reduce?

Answer 42

acid-refflux

Question 43

What neurotransmitter does tryptophan help create?

Answer 43

seretonin