Brainscape's Knowledge GenomeTM

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


See full index

Metabolism > Nitrogen metabolism > Flashcards

Nitrogen metabolism Flashcards

1
Q

is there a store of nitrogen in the body

A
  • No significant store of nitrogen within the body, therefore the nitrogen has to be balanced in the body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

when does positive nitrogen balance happen

A

If intake exceeds output

  • Periods for growth
  • Pregnancy -
  • tissue repair
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

when does negative nitrogen balance happen

A

If output exceeds input

  • indicates body protein breakdown
  • Fasting
  • Trauma
  • Protein malnutrition
  • serious tissue wintry
  • fever
  • wasting diseases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are conditional essential amino acids

A
  • Some capacity to make ourselves but if the demand is particularly high then we have to make them from the diet as well
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are amino acids used for

A
  • Amino acids are essential and important
  • Used to make body proteins
  • Used to make purines, pyrimidines – nucleotides to make new DNA and RNA
  • Used to make thyroxine
  • Used as neurotransmitters – directed in the form of glutamate or indirectly to make noradrenaline
  • Used to make coenzymes and melanin
  • Amino acids are also used to make glucose and ketone bodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what amino acids can be used to make what neurotransmitters

A
  • Tyrosine – important in making melanin, dopamine, adrenaline, noradrenaline dn thyroxine, phenylalanine can compensate for low tyrosine
  • Tyrptophan- serotonin and melatonin
  • Arginine – nitric oxide
  • Histidine – histamine
  • Glycine, glutamate and aspartate – used directly as neurotransmitters
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

if you add an amine group on a Keto acid it..

A

becomes an amino acid

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

what amino acid does pyruvate become

A
  • Pyruvate (keto acid)becomes alanine (amino acids)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what amino acid does alpha ketoglutarate become

A
  • Alpha ketoglutarate (keto acid) becomes glutamate (amino acids)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what amino acid does oxaloacetate become

A
  • Oxaloacetate (keto acid) add an amino group becomes aspartate (amino acids)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what vitamins is required for Keto acids to turn into amino acids

A

B6

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

what sub goroup of amino acids are there

A

glutagenic amino acids and ketogenic amino acids

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

what are glutagenic amino acids used for

A

can be used in glyconeogensis to make glucose

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

name some glutagenic amino acids .

A
  • alanine
  • aspartate
  • glutamine
  • glutamate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what can glutagenic amino acids be used to make

A
  • Alanine can be used to make pyruvate
  • Asparate can be used to make oxaloacetate
  • glutamine and glutamate can be used to make alpha ketoglutarate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are ketogenic amino acids

A
  • these are amino acids that can be used to make ketone bodies
17
Q

describe how ketone amino acids are made

A
  • these ketone bodies are made from acetyl CoA, therefore if you can break the carbon skeleton of an amino acid down to acetyl – CoA then we can make ketone bodies
18
Q

what are the soles ketogenic amino acids

A

leucine

lysine

19
Q

what ketogenic amino acids can make acetoacetyl-CoA

A
  • leucine
  • lysine
  • phenylalanine
  • tyrosine
  • tryptophan
20
Q

what keotgneic amino acids can be used to make acetyl-CoA

A
  • isoleucine
  • leucine
  • tryptophan
21
Q

describe how phenylalanine can be converted to glucose

A
  • Phenylalanine changed to tyrosine
  • This is then broken down into p-hydroxyphenylpyruvate this is then converted to acetoacetate and fumarate which can be broken down to glucose
22
Q

what can phenylalanine compensate for

A
  • Phenylalaine can compensate for low levels of tyrosine
23
Q

what are the branched chain amino acids

A

leucine isoleucine and valaine

24
Q

how are branch amino acids broken down

A
  • Firstly they loose there amino group
  • Then they gain CoA
  • Then there is a dehydrogenation reaction
  • Valine is broken down to succinylCoA
  • Isoleucine to proionylCoA and acetyl CoA
  • And leucine to B-hydroxy-Bmethyl glutaryl CoA and then acetoacetate and acetyl-CoA
25
Q

what is isoleucine broken down into

A
  • Isoleucine to proionylCoA and acetyl CoA
26
Q

what is leucine broken down into

A

leucine to B-hydroxy-Bmethyl glutaryl CoA and then acetoacetate and acetyl-CoA

27
Q

what is valaine broken down into

A
  • Valine is broken down to succinylCoA
28
Q

why is ammonia converted to urea

A
  • Ammonia is basic and highly reactive, it can form neurotransmitters
  • Needs a large amount of water to excrete it
  • Ammonia is converted into urea
  • Urea is more water soluble and less toxic therefore it takes less water to excrete it
29
Q

what are the 3 different fates of glutamate

A
  • Glutamate can undergo a transamination reaction with pyruvate producing alanine and alpha ketoglutarate - alanine can go to the liver where it is converted back to pyruvate producing glutamate, pyruvate is also produced and turned to glucose
  • Or glutamate can be deaminated directly producing alpha ketoglutarate and ammonia – the ammonia can go straight to the kidney where it is disposed of
  • Or glutamate can be converted to glutamine by combining with one molecule of ammonia - this goes to the kidney where it is used for acid base balance
30
Q

what happens to excess amino acids in skeletal muscles

A
  • There is excess amino acids being converted into glutamate
31
Q

what are the enzymes involved in glutamate metabolism

A
  • Glutamate dehydrogenase
  • Glutamate adding an amino group to make glutamine is added by glutamate synthase
  • Glutmase converts glutamine to glutamate and produces ammonia as well
32
Q

what is the role of glutamate

A
  • Skeletal muscle – syntehsised, stored and released in fasting
  • Kidney – substrate for gluconeogenesis; formation of ammonia for buffering protons
  • Central nervous system; shuttle for the maintenance of glutamate as a neurotransmitter
  • Immune cells; fuel and enhances T lymphocyte response to infection; also supports phagocytosis by neutrophils and macrophages
33
Q

describe the urea cycle

A
  • Once in the liver
  • There is the amino acid glutamate this is converted into alpha ketoglutarate and free ammonia by GDH
  • The ammonia is converted to carboamyoyl phosphate by CPS this uses 2 molecules of ATP in the process
  • Carbonyl phosphate is converted to citrulline by combining with ornitihine
  • Then combined with aspartate to make arginosuccinate,
  • Converted to arginine
  • Releases urea and converted back to ornithine
34
Q

how is the urea cycle controlled

A
  • This is through control of CPS
  • It is sensitive to the levels of N-acetyl glutamate
  • This is made by glutamate binding to acetyl-CoA
  • This means that the urea cycle only occurs when the level of glutamate and acetyl-CoA are high
35
Q

what is nitrogen balance

A

Nitrogen balanceis a measure ofnitrogeninput minus nitrogen output.
Nitrogen Balance = Nitrogen intake - Nitrogen loss

36
Q

describe transamination

A
  • chemical reaction between two molecules
  • one is an amino acid which contains an amine group
  • the other is a keto acid which contains a Keto (=0) group
  • the amino group on one molecule is exchanged with the =O group on the other molecule, the amino acid becomes a Keto acid and the Keto acid becomes an amino acid
37
Q

what is the glucose alanine cycle

A
  • this is when the ammonium ion is transported from muscle cells to the liver in the from of alanine
  • through glycolysis glucose becomes pyruvate in the muscle
  • the particular ion of pyruvate in transmiantion reaction produces alanine
  • alanine is then transported into the liver
  • it is then transaminate again and produces pyruvate
  • this can be used for gluconeogensis yielding
  • glucose can be sent again to the muscle and produce energy
38
Q

what does glutamate act as

A
  • it acts as a collector of amino group of the amino acids

- all the amino nitrogen from amino acids that undergo transamination can be concentrated in glutamate

Metabolism (26 decks)

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