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Flashcards in Amino Acids Deck (36):
1

Which is the smallest amino acid? What is it needed for?

Glycine
- Inhibitory neurotransmitter for the spinal cord

2

What does tetanus toxin do?

- Blocks the release of glycine from spinal cord
- Makes muscle contractions much stronger because there is no inhibition by glycine.
- Diaphragm locks up and patients can not breathe.

3

Which are the aromatic amino acids and what do they do?

- Phenylalanine, Tryptophan and Tyrosine
- Are recognized and cleaved to the right by chymotrypsin in proteolysis.

4

Which are the basic amino acids, what do they do?

- Lysine and Arginine
- Are big and bulky
- They have en extra NH3+ (positive charge)
- Are recognized and cleaved to the right by trypsin in proteolysis

5

Which are the acidic amino acids?

- Aspartic Acid and Glutamic Acid
- Have an extra COO- (negative charge)

6

Which is the main amino acid used for reinforcement of behavior in the NMDA pathway? Which medication blocks glutamate inhibition of the NMDA pathway?

- Aspartate
- Used in reinforcement of gambling/addictions
- Memantine blocks glutamate inhibition therefore you have more activity in the pathway

7

Which amino acids contain Sulphur? What are they used for?

- Cysteine and Methionine
- Disulfide bonds
- 4 main hormones with lots of disulfide bonds "PIGI"
1. Prolactin
2. Insulin
3. Growth Hormone
4. Inhibin

8

Which hormones are involved in N-bonds?

- Asparagine and Glutamine
- End in "-ine" and have extra amine group (NH2)

9

Which amino acid is found in elastin? What does it do?

Lysine residues are found in Desmosine which is found in soluble elastin, its positive charges allow for it to recoil.

10

Which amino acids are involved in -O bonds?

Serine, Threonine and Tyrosine
They have an extra -OH group

11

Where is serine found?

On the active site of many enzymes such as serine proteases (Trypsin and Chymotrypsin)

12

Which are the branched chain amino acids?

Leucine, Isoleucine and Valine

13

Which amino acid is used to make catecholamines and melanin?

Tyrosine
- Dopamine => Norepinephrine => Epinephrine

14

Which amino acid is used to make serotonin?

Tryptophan
- Carcinoid syndrome can lead to Tryptophan deficiency
- Because all the Tryptophan is used to make serotonin
- Without tryptophan, can not make Niacin

15

Acidic amino acids will migrate towards?

The anode (positive charge)
- Where anions (negative charge) go

16

Basic amono acids will migrate towards?

The cathode (negative charge).
- Where cations (positive charge) go.

17

Dehydrogenases other than BCAA Dehydrogenase that require 5 vitamins?

Pyruvate dehydrogenase
Alpha-ketoglutarate dehydrogenase
Vitamins are:
Thiamine, Riboflavin, Niacin, Lipoic Acid and Pantothenic Acid

18

Which amino acids are ketogenic?

Lysine and Leucine
- They are made from and broken back into acetyl coA which is used to make ketones.

19

Which amino acids are both Glucogenic and Ketogenic?

Phenylalanine, Isoleucine, Threonine and Tryptophan

20

Which disease causes tryptophan to spill in the urine? What are the signs?

Hartnup's disease
- Presents like pellagra (Diarrhea, dermatitis, dementia and death)
- Defective renal transport of tryptophan
-Tryptophan def => Niacin/Serotonin def.

21

In which patients would you not want to give lysine or leucine?

Type 1 diabetics because they are ketogenic and can lead to diabetic ketoacidosis. Ketones are too acidic leading to an increase in ammonium (NH4) which in turn produces more GABA.

22

Which are the essential amino acids?

PVT TIM HALL
Phenylalanine
Valine
Tryptophan
Threonine
Isoleucine
Methionine
Histamine
Arginine
Leucine
Lysine

23

How does the body utilize energy during starvation?

1. Plasma glucose (2-4 hrs)
2. Liver glycogen (24-48 hrs)
3. Proteolysis (starts at 2 days)
4. Lipolysis (starts at end of day 2
5. Ketogenesis (last resort)

24

If a baby is born with a problem breaking down proteins, when will it manifest?

At 2 days because thats when proteolysis begins.

25

Which cell type relies solely on glucose?

RBC's
Will lead to hepatomegaly and jaundice

26

What amino acid is tyrosine made from?

Phenylalanine, if deficient then tyrosine becomes essential.

27

What amino acid is cysteine made from?

Methionine, if deficient then cysteine becomes essential?

28

What is phenylketonuria?

Phenylalanine hydroxyls deficiency
1. Unable to make Tyrosine
- Therefore can not make dopamine, norepinephrine and epinephrine
- Leads to mental retardation
- Unable to handle stress
2. Unable to make melanin
- Leads to blonde hair, blue eyes, fair skin
- Can lead to skin cancer
3. Build up of phenylacetate and phenylpyruvate
- Phenylalanine attaches to acetyl-coa and pyruvate to make these
- Both are toxic to the brain
- Have a musty odor
- Must have strict diet (avoid aspartame)

29

How are enzyme deficiencies usually transmitted?

Autosomal recessive
- 25% chance of getting it with family hx
- 67% chance of carrying it with family hx

30

How do you test for phenylketonuria?

Guthrie test
- Looks for phenylacetate and phenylpyruvate in the urine.

31

What is the newborn screen?

PKU - Guthrie test
Hypothyroidism - TSH, Asymptomatic in first month
Congenital Adrenal Hyperplasia - 17 hydroxyprogesterone
Biotinidase deficiency -
Galactosemia - Can not breakdown milk
Transglutaminase - Celiac sprue (common)
Immunoreactiive Trypsin - Cystic fibrosis

32

What is albinism?

Tyrosinase deficiency
Predisposes to skin cancer becasue there is no pigment to block the suns rays
Tx: SPF 30 blocks 96% of suns rays

33

What is vitiligo?

Autoimmune antibodies against melanocytes
Predisposes to skin cancer
Usually starts in the face

34

What is Alkaptonuria (ochronosis) ?

Homogentisic acid oxidase deficiency
Tyrosine builds up because no homogentisic acid to oxidize it.
Tyrosine backs up and enters melanin pathway.
Leads to black nasal septum, tendons and ears.
Can lead to arthritis
Urine turns black when exposed to air.

35

What is maple syrup urine

Defective transport of BCAA's
Defective transport in collecting duct of the kidney.
Leucine, Isoleucine, Valine
Urine tastes like maple syrup or smells like burnt sugar.

36

What is Cystinuria?

Defective renal transport of COLA
Cysteine, Ornithine, Lysine and Arginine
Hexagonal, enveloped shaped or coffin shaped crystals in the urine.