Amino Acids Flashcards

wk 10

1
Q

can essential amino acids be synthesised in the human body?

A

no

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2
Q

What are nonessential amino acids formed from?

A

metabolic intermediates or from other amino acids

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3
Q

What are Glucogenic classification of amino acids?

A

Used to synthesise glucose (using TCA/ Pyruvate)

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4
Q

What are ketogenic classification of amino acids?

A

Make acetyl-CoA

OR used to synthesis ketone bodies or fatty acids

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5
Q

What is the classification of phenylalanine?

A

Amino acids that re both glycogenic and ketogenic

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6
Q

How is Nitrogen removed from the amino group so can enter the urea cycle?

A

removing amino group and transferring to a-ketoglutarate = glutamate

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7
Q

What does pyruvate becomes after transamination (in muscle cells after glycolysis)

A

Alanine

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8
Q

What occurs in the Glucose-alanine cycle?

A

Ammonium ion in muscle cells –> liver as alanine –> secreted eventually as urea.

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9
Q

What is the most important ammonia-forming reaction?

A

oxidative deamination of glutamate via GDH in the liver.

reversible (synthesis and degrades glutamate)

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9
Q
A
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10
Q

Where is Glutamine formed and what is its major role?

A

from glutamate using glutamine synthease

goes to liver, kidney and intestines

removes a N and transports it to the liver.

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11
Q

How are amino groups of amino acids turned into ammonia?

A

By transamination and oxidative deamination

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12
Q

What is the purpose of the Urea cycle?

A

removal of excess NH4+

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13
Q

What is the Net Reaction of the Urea cycle?

A

NH4+ + HC03- + asparate + 3ATP –> urea + fumarate + 2 ADP + 2Pi + AMP + PPi

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14
Q

How many molecules of urea are produced per urea?

A

4 ATP

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15
Q

What is the key regulator of the urea cycle?

A

CPS-I

16
Q

What type of enzyme is CPS-I and when is it activated?

A

mitochondrial enzyme

activated by N-acetylglutanate when there are high levels of glutamate and arginine.

17
Q

What does an overproduction of dopamine result in?

A

Schizophrenia

18
Q

What does a genetic deficiency of phenylalanine Hydroxylase result in?

A

Phenylketonuria - mental retardation if not treated immediately after birth

19
Q

What part of Nitrogen is toxic?

A

NH2

20
Q

How can N be lost and what needs to happen?

A

Protein and nucleic acid degradation- needs to be replaced