Lecture 39: Nitrogen fixation-amino acid biosynthesis Flashcards Preview

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Flashcards in Lecture 39: Nitrogen fixation-amino acid biosynthesis Deck (19)
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1

Amino Acid Biosynthesis

-Plant and microorganisms can make all 20 amino acids
-all others need nitrogen metabolites. In these organisms glutamate is the source of nitrogen via transamination reactions
-Mammals can only synthesize 10 of the amino acids.
-the other 10 are called essential amino acids and must be obtained through the diet

2

Where do plants and microorganims obtain the 20 amino acids?

they synthesize all 20 amino acids from metabolic precursors that originate in the glycolysis, TCA cycle, or pentose phosphate pathay

3

Name 5 of the essential amino acids?

Lysine
Valine
Leucine
Isoleucine
Methionine

4

What are some conditional amino acids?

Glutamine
Proline
Arginine
Glycine
Cysteine

5

conditional amino acids

amino acids that synthesis are limited in young, illness, growing animals

6

Negative Nitrogen Balance

happens when dietary intake of even one essential amino is not enough to meet demand. Thus more protein is broken down than is synthesize and more nitrogen is excreted than is ingested

7

What does the complexity of an amino acid biosynthetic pathway depends on?

the number of moles of ATP required

8

Phenylketonuria

PKU
1) results from deficiencies in phenylalanine hydroxylase
2)Important for conversion of phenylalanine
-PKU-Phe accumulates in the blood
-Tyrosine is a building block for neutransmitters, dopamine, noradrenaline, and adrenaline
-Phenylalanin also blocks the transporter that transfers large neutral amino acids into the brain
3)Effects of PKU: mental retardation
4)Treatment: diet
5)PKU is detected by detecting phenylketones in the urine

9

Roles of Glutathione

-leads to reducing intracellular enviroment
-involved in drug metabolism conjugation to drug for elimination in feces/urine)

10

Degradation of Amino Acids

1. The 20 amino acids are degraded to produce TCA intermediates mostly
2.Energy requirements
-90% from oxidation of carbohydrate and fats
-10% from oxidation of amino acids
3. primary physiological purpose of amino acids is to serve as building blocks for protein synthesis
4. Amino acids are either glycogenic or ketogenic

11

Glutogenic Amino Acids

-the amino acids that are converted to precursors for glucose synthesis such as a-ketogluterate, saucily-CoA, fumarate, oxaloacetate, and pyruvate

12

Ketogenic Amino acids

-the amino acids that are converted to acetyl-CoA or acetoacetate which are precursors for synthesis of fatty acids and ketone bodies

13

what amino acids are glucogenic due to pyruvate?

-Ala
-Ser
-Cys
-Gly
-Thr
-Trp

14

What amino acids are glucogenic due to oxaloacetate?

Asp
Asn

15

What amino acids are glucogenic due to fumarate?

Asp
Phe
Tyr

16

What amino acids are glucogenic due to a-ketogluterate

-Glu
-Gln
-Arg
-Pro
-His

17

What amino acids are glucogenic due to Succinyl-CoA

-ile
-Met
-Val
-Thr

18

What amino acids are ketogenic due to acetoacetate

-Phe
-Tyr
-ile
-leu
-lys
-trp
-thr

19

what amino acids are ketogenic due to Acetyl-CoA

-Phe
-Tyr
-Leu
-Lys
-Trp