Lecture 4 (2B) - Amino Acid Biosynthesis Flashcards

Question

3-phosphoglycerate to... (picture)

Answer 1

A

known as essential amino acids

Answer 2

A

made by humans

Answer 3

A

from phenylalanine that’s essential
disease of last lecture (alkaptonuria, phenylketonuria)
can’t make it if no phenylalanine comes from outside

Answer 4

A

from outside

Answer 5

A

pyruvate
oxaloacetate
α-ketoglutarate

(associated with citric acid cycle)

3-phosphoglycerate

(glycolysis - toward citric acid cycle but not associated)

Answer 6

A

pyruvate (ketone) → alanine (amino acid)
oxaloacetate (ketone) → aspartate → asparagine
α-ketoglutarate (ketone) → glutamate → glutamine

Answer 7

A

remove amide group from 1 amino acid → forms α-ketoacid
place amide group on another α-ketoacid → forms another amino acid
also similar for side chains
amide through ketone to another

Answer 8

A

catabolism of amino acids (to make others)

biosynthesis of other small molecules

Answer 9

A

glutamate **→* **glutamate-5-phosphate → glutamate-5(γ)-semialdehyde → Δ’-pyrroline-5-carboxylate → proline

* = steps between

activation in the form of acyl-phosphate intermediate
not seen because highly unstable (highly reactive)
channels unstable intermediate between sites → can’t be seen (keep from doing side reactions)

Answer 10

A

glutamate-5-phosphate is unstable
- not seen, only implied
multi-enzyme system
kept within structure

Answer 11

A

get to glutamate-5(γ)-semialdehyde (2 steps through intermediate)
from there branch to ornithine

OR

GLUTAMATE to ARGININE

Answer 12

A

glutamate

→

N-acetylglutamate

(in control of urea cycle)

(activation)

→

N-acetylglutamate-5-phosphate

→

N-acetylglutamate-5-semialdehyde

→

N-acetylornithine

→

ornithine

→

urea cycle

→

arginine

Answer 13

A

forms:

serine
cysteine
glycine

Answer 14

A

to serine → 3 steps

(oxidation to activate, transamination, hydroxyl comes in)

(makes amino acid backbone)

from serine to cysteine → 2 steps

(methionine breakkdwon, add H₂O, remove H₂O)

(serine = mainchain backbone to make cysteine)

from serine to glycine

serine + THF → Glyine + N⁵-methyl-THF + H₂O

similar processes are linked to different molecules

Answer 15

A

the aspartate family
the pyruvate family
the aromatic amino acids

Answer 16

A

lysine
methionine
threonine

Answer 17

A

leucine
isoleucine
valine
valine and isoleucine have same pathways EXCEPT for the first step
leucine from valine pathway

Answer 18

A

phenylalanine
tyrosine
tryptophan
all have common precursor - CHORISMATE

Answer 19

A

shared first step
chorismate → prephenate
- chemical makeup identical
from prephenate → tyrosine
- through 4-hydroxy phenylpyruvate
- oxidation/reduction + decarboxylation (keep hydroxyl) → transamination
from prephate to phenylalanine
- through phenylpyruvate
- decarnboxylation (lose hydroxyl) → transamination

Answer 20

A

prephenate → tyrosine

through 4-hydroxyplenylpyruvate
oxidation/reduction + decaroxylation (keep hydroxyl) → transamination

Answer 21

A

prephenate → phenylalanine

through phenylpyruvate
decarboxylation (lose hydroxyl) → transamination

Answer 22

A

6 step process by tryptophan synthase
- must channel molecules through sites to ensure it doesn’t drift off for something else

removing pyruvate, adding amide
adding a sugar
sugar ring cleavage
new ring fromed
indole formed

indole ring very reactive
precursor to sidechain of tryptophan

serine added
* to make main chain carbons (like cysteine)

→ tryptophan formed

Answer 23

A

most concerned with catabolism (breakdown) of amino acids

Answer 24

A

feeding = missing low concentrations in testes
2 diseases form
3-phosphoserine phosphatase deficiency
- for phosphate activation
- exceptionally rare - only a single case
- rare because nonessential so very detrimental so usually die in womb