Brainscape's Knowledge GenomeTM

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


See full index

Nutrition and Metabolism > Amino Acid Metabolism > Flashcards

Amino Acid Metabolism Flashcards

1
Q

Name the 10 essential amino acids.

A

PVT TIM HALL
Phenylalanine
Valine
Threonine

Tryptophan
Isoleucine
Methionine

Histidine
Ariginine
Leucine
Lycine

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

What is the importance of dietary protein?

A

Required for synthesis of neurotransmitters, creatine, carnitine, haem, purines and pyrimidines.

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

What causes gout?

A

High uric acid released from metabolism of creatine, purines and pyrimidines

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

What is the average protein turnover in adults?

A

300-400g

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

What is the amino acid pool?

A

Free amino acids - there is no storage form of protein so high protein diet in excess is wasteful.

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

What is positive nitrogen balance? When does it occur?

A

Nitrogen intake is greater than nitrogen excretion.
During normal growth in children.
In convalescence after illness
In pregnancy

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

What is negative nitrogen balance? When does it occur?

A

When nitrogen intake is lower than nitrogen excreted.
Occurs during starvation.
During serious injury or trauma
If not corrected will lead to irreversible loss of body tissue - ultimately leading to death.

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

What is an amino acid?

A

Single unit of protein made up of amino group, carboxyl group and H-C-R variable group.
Amino acid = keto acid + amino group

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

How does pyruvate relate to alanine?

A

Pyruvate (keto acid) = HOOC-C=O-CH3
Alanine (amino acid) = HOOC-C(NH2)H-CH3

In alanine =O is replaced with NH2.

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

What is transamination?

A

Transfer of an amino group from one molecule to another.
Amino acid1 + keto acid2 > keto acid1 + amino acid2
Catalysed by aminotransferase enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What enzymes catalysed transamination reaction?

A

Aminotransferase enzymes.

All contain prosthetic group derived from vitamin B6 - pyridoxal phosphate or pyridoxamine.

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

How is are amino acids used in gluconeogensis?

A

Carbon-skeleton of the amino acid will form part of the TCA cycle.

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

What is deamination?

A

Removal of an amino group from an amino acid to form a keto acid and ammonia.
Requires a co-enzyme.
amino acid + H2O + coenzyme > keto-acid + ammonia + reduced-coenzyme

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

What enzyme catalyses the deamination of L-glutamate to 2-oxo-glutarate?

A

Glutamate dehydrogenase

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

What are glucogenic amino acids?

A

13 amino acids

Their carbon-skeleton can be converted back to glucose by the liver

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

What are ketogenic amino acids?

A

Amino acids which can be degraded directly into acetyl CoA
Leucine and lysine are only degraded to acetyl CoA
Phenylalanine and tyrosine are both glucogenic and ketogenic.

17
Q

Give 5 roles of the liver in nitrogen metabolism.

A

Removal of amino acids from portal blood supply
Absorption of amino acids for synthesis of cellular proteins and plasma proteins
Synthesis of haem, purines and pyrimidines for DNA and RNA
Degradation of amino acids by transdeamination
Conversion of NH3 to urea for excretion

18
Q

How are amino groups transported to the liver?

A

Via glutamine in the blood.

Glutamine > Glutamate + NH3

19
Q

What enzyme converts glutamine to glutamate?

A

Glutaminase

Uses H2O

20
Q

What enzyme converts glutamate to glutamine?

A

Glutamine synthetase

Uses ATP

21
Q

How many amino groups does urea have and where do these groups come from in the urea cycle?

A

2 groups
1st from glutamine metabolism
2nd from aspartate

22
Q

Outline the urea cycle.

A

NH4+ + CO2 +2ATP > NH2COP(carbamoyl phosphate) + 2ADP + Pi
Carbamoyl phsophate + ornithine > citrulline
Citrulline + aspartate > arginosuccinate > fumarate + arginine
Arginine > UREA + ornithine

23
Q

What are the 4 end products of nitrogen metabolism?

A

Urea - protein breakdown
Creatinine - creatine phosphate breakdown
Uric acid - DNA and RNA breakdown
Ammonia - control of body pH

24
Q

What is hyperammonaemia?

A

Excess ammonia is neurotoxic.
Caused by impaired conversion of NH3 to urea due to liver failure or genetic defects (X-linked inheritance of ornithine transcarbamoylase deficiency).
Leads to cerebral oedema, coma and death.

Nutrition and Metabolism (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions