Protein 3

Question 1

1. List the sulfer containing amino acids.

Answer 1

methionine

Cysteine

Question 2

2. Describe the biological utility of Cys in regard to its oxidative state (alone or within GSH).

Answer 2

Cysteine is reduced inside oxidized outside
Cysteine plus glycine + glutamate= glutathione
glutathione is reduced by NADPH and used to:
-fight free radicals
-keep proteins in there reduced form
-control how proteins form (chaperones
-regulate hemoglobin, keeps in them in ferrous state

Question 3

3. Describe Met, its relation to SAM and the energy provided in SAM.

Answer 3

Methione makes Sam by SAM synthase and ATP

SAM also called ado met (activated sulfur)

Question 4

4. Describe diseases related to Cys and Met metabolism including hyperhomocysteinemia, homocystinuria, cysteinuria, and vascular disease.

Answer 4

homocysteinuria- defect in CBS enzyme

• Mental retardation
• osteoporosis
• vascular disease
• makes cysteine essential
• a certain subset u can treat with vit b6

Hyper homocysteinuria (from low folate b6 b12)
-treat with B vitamins

Cysteinuria- kidney stones (renal failure), due to defective in transporter of cysteine ( Ornithine, Lysine, Arginine) that leads to crystallization (in kidneys), treat with acetazolamide that makes cysteine more soluble

Vascular disease- (from low folate b6 b12)
-treat with B vitamins

Question 5

5. Describe where vitamins are used in Cys and Met metabolism including folate, B6, and B12.

Answer 5

folate and B12 are used in taking homocysteine back to methionine in the methionine synthetase rxn

b6 takes homocysteine to cystathione and cystathione to cysteine

Question 6

6. List biologically important molecules derived from Trp metabolism.

Answer 6

seratonin
niacin
melatonin

dependent on BH4

Question 7

7. Describe diseases related to Phe, Tyr metabolism including phenylketonuria (PKU), tyrosinemia, Parkinson’s disease (PD), and the use of monoamine oxidase (MAO) inhibitors.

Answer 7

Parkinson’s Disease (PD)

1. Degenerative disorder of central nervous system (loss of motor skills).
2. Loss of neurons–>Low Dopamine–>Parkinson’s
3. Treatment
   - Treat with Dopa
   - Treat with Monoamine oxidase (MAO) inhibitors.
   - Treat with catacholamine Mtase inhibitors.