Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IBMS SR > Amino Acid Metabolism > Flashcards

Amino Acid Metabolism Flashcards

1
Q

how many naturally occurring amino acids are there

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how many naturally occurring amino acids are essential

A

9/20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

which amino acids need to be obtained from the diet

A 
histidine 
valine
leucine 
isoleucine 
lysine 
methionine 
threonine 
phenylalanine 
tryptophan
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are amino acids used for

A

building blocks for protein and peptide synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

which amino acid needs to be obtained in the diet in childhood but not adulthood

A

arginine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

which element is found in amino acids

A

nitrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what can amino acids also form

A

fatty acids
ketone bodies
glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are amino acids also used as

A

metabolic fuels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

where does protein degradation occur

A

in the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how do proteins become degraded

A
  1. transported into the lumen where they are broken down into oligopeptides and dipeptides/tripeptides by amino peptidases
  2. transported into the intestinal cell by diffusion and then into the blood where they can be transported to where necessary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

why do we need a lot of argentine in childhood

A

necessary for growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

which enzyme denatures in the stomach

A

pepsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where are excess amino acids stored

A

they cannot be stored and are excreted through the urea cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is transamination

A

the switching of one amino group to another on the same amino acid eg valine to tryptophan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is oxidative deamination

A

the removal of the amino group off the amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is transdeamination

A

transamination + oxidative deamination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

which enzymes are essential for the transamination stage

A

aminotransferases and pyridoxal phosphate as a COFACTOR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

which cofactor is used in transamination

A

pyridoxal phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is PLP

A

aminotransferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how is pyridoxine attached

A

it is attached to an amino acid by a schiff base linkage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is internal aldimine

A

the pyridoxine attached to the amino acid is membrane bound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is external aldimine

A

the pyridoxine attached to the amino acid is not membrane bound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how do we form and remove a ketoacid in our examine using aldimine

A

in the example: aldinmine forms a quinonoid intermediate then a ketimine and the pyridoxamine phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the general formation and removal of a ketoacid

A

PLP accepts the amino group which forms a ketoacid and then an intermediate PMP. then PMP donates the amino group to an incoming alpha ketoacid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what do all the amino groups of all the different amino acids end up forming

A

glutamate- as then we only need one processing pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how is glutamine formed

A

from the amino acid + a ketogluterate to form oxaloacetate + glutamate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what form do amino acid groups from muscle protein degredation arrive in the liver from the blood

A

alanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what form do amino acid groups from non liver tissues arrive in the liver from the blood

29
Q

can amino acids be stored

A

no they’re excreted as urea

30
Q

how much nitrogen should we have a day in our diet

A

35-55g per day

31
Q

what does the breakdown of amino acids lead to

A

a net loss of nitrogen

32
Q

what does the rate of protein turnover depend on

A

the protein type-
regulatory
structural
haemoglobin

33
Q

how does the body know which proteins to break down

A

by ubiquitin tags

34
Q

how does a ubiquitin tag form

A

at the carboxyl end, a glycine residue attaches to a lysine residue to form a ubiquitin C glycine-lysine target protein

35
Q

what determines whether the protein needs to be degraded or not

36
Q

how does E3 determine which protein gets degraded

A

by the N end rule

lysosomal pathway

37
Q

what is the N end rule

A

divides proteins into long or short liver species based on the N terminal amino acid
stabilising residues or non stabilising residues

38
Q

what are stabilising residues

A

serine
alanine
glycine
don’t tag

39
Q

what are destabilising residues

A

arginine
tryptophan
phenylalanine
does tag and is depredated

40
Q

what is the PEST rule

A

speeds up degradation- proline glutamic acid serine and threonine

41
Q

when is the lysosomal pathway used

A

breaks down long lived proteins/membrane/organelles

42
Q

describe the lysosomal pathway for an external protein

A

1.the protein enters via endocytosis
2. fuses with a lysosome and forms an endolysosome
3. lysosomal proteases degrade proteins
IF the protein is already in the cell

43
Q

describe the lysosomal pathway for an internal protein

A

engulfed by the endoplasmic reticulum to form autophagosomes and then lysosomal proteases degrade proteins

44
Q

how is toxic ammonia formed

A

from the amino group of the amino acid being removed

45
Q

what does the urea cycle produce

A

ammonia is converted into urea by the urea cycle and removed in our urine

46
Q

when does amino acid degradation occur

47
Q

describe the steps of the urea cycle

A

forms urea from 2 compounds of C02 and NH4
first reactions occur in the mitochondria
3 in the cytosol

48
Q

what is urea made up from

A

one nitrogen atom from ammonia from the transdeamination of AA
one nitrogen atom from aspartate

49
Q

describe step 1 of the urea cycle

A

bicarbonate + ammonia + 2ATP forms carbamoyl phosphate with the enzyme carbomyl phosphate synthetase 1

50
Q

how is carbomyl phosphate synthetase 1 activated

A

by N acetyl glutamate

51
Q

describe step 2 of the urea cycle

A

carbamoyl phosphate interacts with ornithine is converted into citruline by the enzyme ornithine transcarbamoylase

52
Q

describe step 3 of the urea cycle

A

condensation reaction of citrulline and aspartate to form arginosuccinate

53
Q

describe step 4 of the urea cycle

A

cleavage of arginosuccunate to form arginine using arginosuccinase

54
Q

describe step 5

A

cleavage of arginine to ornithine and the formation of urea via anginase

55
Q

what can happen to fumarate

A

converted into malate by fumerase

can be transported into the mitochondria and enter the TCA cycle

56
Q

what is hyperammonaemia

A

elevated symptoms of ammonia intoxication

57
Q

what are the symptoms of hyperammonaemia- ammonia intoxication

A

blurred vision
slurred speech
tremors

58
Q

what are the symptoms of hyperammonaemia in extremely high concentration

A

coma
brain damage
death

59
Q

how does ammonia toxicity work

A

depletion in alpha ketoglutarate and reduction in the TCA cycle

60
Q

what is a common genetic deficiency seen in the TCA cycle

A

ornithine transcabamoylase

61
Q

what do genetic deficiencies lead to

A

hyperammonaemia and irreversible mental retardation due to toxicity

62
Q

where is ammonia toxicity also seen

A

in patients with liver damage due to cirrhosis

63
Q

how do we treat urea cycle failure

A

benzoate- forms hippurate
phenylbutyrate- forms phenylacetylglutamine
both forms are excreted

64
Q

what are the two stages of amino acid breakdown

A

removal of amino groups

the catabolism of the carbon skeleton

65
Q

what are the classes of amino acids

A

ketogenic

glucogenic

66
Q

what are ketogenic AA

A

broken down in either acetyl coA or acetoacetyl coA

67
Q

what are glucogenic Aa

A

amino acids broken down into pyruvate or one of the intermediates

68
Q

what does phenylketonuria mean

A

deficiency of phenylalanine hydroxylase

IBMS SR (38 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions