amino acid biosynthesis

Question 1

how many amino acids can we produce (non-essential)

Answer 1

10

Question 2

list the 10 non-essential amino acids

Answer 2

alanine, glutamate, glutamine, proline, arginine, serine, glycine, cysteine, aspartate, asparagine

Question 3

list 3 ways in which amino acids are derived

Answer 3

glycolysis intermediates, CAC intermediates, PPP intermediates

Question 4

describe how amino acids can be derived from the PPP

Answer 4

Glucose-6-P can be converted to metabolites by donating electrons to NADP+, producing lots of NADPH

Question 5

what do aminotransferases do

Answer 5

move amino groups from one molecule to another

Question 6

what is the name of the leftover molecule when an aminotransferase removes it’s amino group

Answer 6

carbon skeleton

Question 7

which amino group was removed to create a carbon skeleton: backbone or R group

Answer 7

backbone (because not every a.a has an R group amine)

Question 8

what is another name (the chemical name) for an amino acid minus its R group

Answer 8

a-keto acid

Question 9

last class we saw that a-KG can make glutamate which can then make glutamine. List the other two derivatives of glutamate (aka a-KG derivatives)

Answer 9

proline and arginine

Question 10

describe how proline is made from glutamate

Answer 10

glutamate is reduced by dehydrogenase and NADPH, The resulting molecule is spontaneously (non-enzymatically) cyclized. A final NADPH reduction = proline

Question 11

to make proline: what enzyme is used

Answer 11

glutamate dehydrogenase

Question 12

to make proline: ATP cost?

Answer 12

1 ATP

Question 13

to make proline: NADPH cost?

Answer 13

uses 2 NADPH

Question 14

describe how you make arginine from glutamate

Answer 14

reduce glutamate with NADPH. Aminotransferase introduces a second amino group, leaving glutamate as a-KG. Resulting molecule = ornithine, which enters the urea cycle to form arginine

Question 15

to make arginine: enzymes used?

Answer 15

aminotransferase

Question 16

to make arginine: ATP cost?

Answer 16

2 ATP

Question 17

to make arginine: NADPH cost?

Answer 17

1 NADPH used

Question 18

to make arginine: what intermediate is produced

Answer 18

ornithine

Question 19

to make arginine: what happens to ornithine during the pathway

Answer 19

it enters the urea cycle to eventually form arginine

Question 20

how many amino groups does arginine have

Answer 20

4

Question 21

how many amino groups does urea have

Answer 21

2

Question 22

what amino acid is produced from 3-phosphoglycerate? what amino acids does that produce?

Answer 22

serine, which makes glycine and cysteine

Question 23

describe how we make serine from 3-phosphoglycerate

Answer 23

3-PG is oxidized by NAD+. Aminotransferase adds an amino group. Phosphatase removes the phosphate

Question 24

to make serine: enzymes used?

Answer 24

aminotransferase and phosphatase

Question 25

to make serine: ATP cost?

Answer 25

none

Question 26

to make serine: byproducts? (ie are the electron carriers oxidized or reduced)

Answer 26

NAD+ is used, NADH is produced

Question 27

describe how glycine is produced from serine

Answer 27

hydroxymethyltransferase removed OH and methyl group from serine

Question 28

to make glycine: enzymes used?

Answer 28

hydroxymethyltransferase

Question 29

to make glycine: ATP cost?

Answer 29

none

Question 30

to make glycine: and electron carriers?

Answer 30

none

Question 31

describe how to make cysteine from serine

Answer 31

plants uptake sulfates (SO4 2-) from the soil which are reduced by NADPH to sulfide (S2-). The sulfide is exchanged for the serine OH

Question 32

to make cysteine: enzymes used?

Answer 32

none that are mentioned (S is replaced with OH)

Question 33

to make cysteine: ATP cost?

Answer 33

none

Question 34

to make cysteine: electron carriers?

Answer 34

NADPH used

Question 35

which amino acid does OAA make

Answer 35

aspartate

Question 36

which amino acid does aspartate make (that we can synthesize)

Answer 36

asparagine

Question 37

which amino acid does pyruvate make (that we can synthesize)

Answer 37

alanine

Question 38

describe how alanine is made from pyruvate

Answer 38

pyruvate is transaminated via aminotransferase

Question 39

describe how aspartate is made from OAA

Answer 39

OAA is transaminated via aminotransferase

Question 40

describe how asparagine is made from aspartate

Answer 40

aspartate is amidated. Glutamine donates the NH4+. Enzyme used = asparagine synthetase

Question 41

to make asparagine: enzyme?

Answer 41

asparagine synthetase

Question 42

to make asparagine: ATP cost?

Answer 42

1 ATP used

Question 43

what does ALL stand for

Answer 43

acute lymphoblastic leukemia

Question 44

ALL produces an overabundance of _____________

Answer 44

immature lymphocytes

Question 45

what does "acute" mean in acute lymphoblastic leukemia

Answer 45

cancer progresses rapidly, developing within weeks and becoming possibly fatal within months

Question 46

which enzyme is produced in very little amounts in the malignant lymphocytes in ALL

Answer 46

asparagine synthetase

Question 47

synthesis of which amino is blocked during ALL? why? how do people with ALL get this amino acid?

Answer 47

synthesis of asparagine is blocked since very little asparagine synthetase is produced in the malignant lymphocytes. They must acquire it from the diet

Question 48

treatment for ALL involves which enzyme

Answer 48

asparaginase

Question 49

describe the actions of asparaginase enzyme in ALL treatment

Answer 49

the enzyme depletes asparagine in the blood serum, removing the extracellular source of it for these cancer cells = cuts off the asparagine source for the bad cells

Question 50

in ALL treatment, what happens to the cancerous cells once asparaginase removes the extracellular source of asparagine

Answer 50

without ability to synthesize Asn and no Asn to utilize from the surrounding serum, the cells die

Question 51

which amino acids are derived from PEP

Answer 51

the ringed amino acids: phenylalanine, tyrosine, tryptophan

Question 52

T or F: PEP is the only thing that can make tyrosine

Answer 52

false; it can also be made from phenylalanine

Question 53

before making the three ringed amino acids, what does PEP need to make?

Answer 53

chorismate

Question 54

describe how chorismate is made from PEP

Answer 54

2x PEP (3C) and erythrose 4-phosphate (4C) form 10C chorismate

Question 55

describe how tyrosine is made from chorismate (PEP)

Answer 55

a mutase swaps groups off the chorismate ring. the intermediate is then oxidized, decarboxylated, and transaminated

Question 56

describe how phenylalanine is made from chorismate (PEP)

Answer 56

a mutase swaps groups off the chorismate ring. The intermediate is then decarboxylated and transaminated

Question 57

formation of which amino acid involves oxidation: tyrosine or phenylalanine

Answer 57

tyrosine

Question 58

what amino acid is formed from ribose-5-phosphate

Answer 58

histidine

Question 59

what intermediate must be made from ribose-5-P before histidine formation

Answer 59

5-phosphoribosyl-1-pyrophosphate (PRPP)

Question 60

how many phosphates does PRPP have

Answer 60

3

Question 61

once PRPP is formed from ribose-5-P, describe how histidine is formed

Answer 61

histidine is formed from 5 PRPP carbons and 2 oxygens, a nitrogen and carbon from the adenine ring of ATP, a nitrogen from glutamine, and a nitrogen from glutamate

Question 62

list the molecules that contribute atoms to histidine

Answer 62

glutamine, PRPP, glutamate, adenine

Question 63

some of the byproducts from histidine synthesis can be used for ___ synthesis

Answer 63

purine

Question 64

what type of feedback inhibition regulates amino acid synthesis pathways

Answer 64

allosteric feedback inhibition

Question 65

why is allosteric feedback inhibition used to regulate amino acid synthesis pathways

Answer 65

to ensure amino acids aren't made when they're already in high concentrations

Question 66

why can negative feedback inhibition be problematic

Answer 66

problematic when the same intermediate is needed for multiple amino acids, but it's being inhibited by one product

Question 67

describe how enzyme multiplicity comes into play with a.a synthesis regulation

Answer 67

the enzymes in a pathway will have multiple isozymes, and isozymes are inhibited by different molecules in the pathway. This way, inhibition of A1 isozyme by one product reduces overall A activity, but A2 and A3 are still active to make the other products

Question 68

T or F: the effect of enzyme multiplicity inhibitors is cumulative

Answer 68

true

Question 69

list 6 amino acid derivatives

Answer 69

nucleotides, heme, lignin, auxin, alkaloids, neurotransmitters

Question 70

what is heme a derivative of

Answer 70

glycine

Question 71

heme is required for proper function of both ___ and ___

Answer 71

hemoglobin and cytochromes

Question 72

heme degrades into __ and __

Answer 72

Fe2+ and bilirubin

Question 73

where/in what conditions will heme be degraded into Fe2+ and bilirubin

Answer 73

occurs in damaged/dying RBCs in the spleen

Question 74

T or F: bilirubin is insoluble

Answer 74

true

Question 75

from the spleen, where does bilirubin travel to

Answer 75

liver

Question 76

how does bilirubin travel to the liver

Answer 76

bound to serum albumin

Question 77

what happens to bilirubin upon arrival to the liver

Answer 77

converts to a water soluble bile pigment in the liver and released into the small intestine

Question 78

what happens to bile pigment once it's made from bilirubin in the liver and enters the small intestine

Answer 78

some of it makes its way to the kidneys and a derivative helps make urine yellow

Question 79

T or F: bilirubin makes urine yellow

Answer 79

false; a derivative of bilirubin makes urine yellow

Question 80

T or F: bilirubin makes feces brown

Answer 80

false; a derivative makes feces brown

Question 81

describe what happens when you bruise

Answer 81

blood vessels in/near the skin burst and the damaged RBCs release heme

Question 82

why do bruises change color

Answer 82

occurs as heme loses oxygen

Question 83

describe what happens as bruises change from purple to yellow

Answer 83

heme loses oxygen = purple. Heme degrades into an intermediate biliverdin = green, and eventually bilirubin = yellow

Question 84

what happens if bilirubin is in the blood (caused by excess bilirubin)

Answer 84

leads to jaundice

Question 85

what is lignin a derivative of

Answer 85

phenylalanine and tyrosine

Question 86

what is the role of lignin

Answer 86

forms secondary cell walls in plants, large component of wood and bark

Question 87

what is auxin a derivative of

Answer 87

tryptophan

Question 88

role of auxin?

Answer 88

regulates shoot/fruit/lead growth and helps stems bend towards light

Question 89

what part of the plant secretes auxin

Answer 89

the tip of the plant shoot

Question 90

what are flavoured molecules derivatives of

Answer 90

phenylalanine and tyrosine

Question 91

what are alkaloids derivatives of

Answer 91

phenylalanine and tyrosoine

Question 92

what are alkaloids

Answer 92

nitrogenous chemicals formed in plants

Question 93

list 4 alkaloids

Answer 93

caffeine, capsaicin, morphine, nicotine

Question 94

what are neurotransmitters derivatives of

Answer 94

tyrosine, glutamate, tryptophan, histidine

Question 95

_____ is a key step in most pathways to synthesize NTs

Answer 95

decarboxylation

Question 96

list 5 NTs

Answer 96

epinephrine, norepinephrine, histamine, serotonin, GABA