E3 General Questions

What protein carries Fatty Acids through the blood stream to target tissues

Serum Albdumin

Which signaling molecule initiates catabolism of stored fats?

Glucagon

What proteins are located around fat in adipocytes and change orientation when FA need to be accessed?

Perilipin

What enzymes are required to transport FA from blood into the mitochondria? (3)

Fatty Acyl-CoA Synthase

CAT1 (CTP1)

CAT2 (CTP2)

What molecule is added to Fatty Acyl-CoA that allows it to be taken up into the mitochondria?

Carnitine

Why is Fatty Acyl-CoA introduced into Beta-Oxidation (instead of just a Fatty Acid)?

The acyl-CoA energizes the bond for B-Ox

What are the 4 major steps of Beta-Oxidation? (not enzymes)

Oxidation

Hydration

Oxidation

Cleavage

What are the enzymes of Beta-Oxidation?

Acetyl-CoA Dehydrogenase

Enoyl-CoA Hydratase

B-Hydroxyacyl-CoA Dehydrogenase

Acetyl-CoA Acyltransferase (Thiolase)

How many rounds does it take to fully oxidize Palmotyl-CoA in Beta-Oxidation?

7 rounds

How/Why is Propionyl-CoA (3C) generated by Beta-Oxidation

Its generated when a FA with an odd amount of carbons is oxidized by the pathway. It can still be used in the TCA, just like the Acetyl-CoA that’s normally produced.

What’s the overall reaction of Beta-Oxidation?

Palmitoyl-CoA + 7CoA + 7FAD + 7NAD+ + 7H2O → 8 acetyl-CoA + 7FADH2 + 7NADH + 7H+

How is acetyl-CoA that’s produced by the liver (in Beta-Oxidation) transported to target tissue?

Acetyl-CoA is transported in the form of ketone bodies

What is ketoacidosis

when ketones, produced by ketogenesis, make blood too acidic

key ketones: Acetone, Beta-Hydroxybutyrate

Fatty Acid synthesis general reaction

8 Acetyl-CoA + 14NADPH + 7ATP + 14H+ → Palmitate (C16) + 14NADP+ 8CoA + 7ADP + 7Pi + 6H2O

Acetyl-CoA Carboxylase is similar to what other enzyme and requires what cofactor to function?

Acetyl-CoA Carboxylase is similar to Pyruvate Dehydrogenase and requires the cofactor biotin.

What is the rate limiting step of Fatty Acid synthesis?

Acetyl-CoA Carboxylase

What is the reaction for Acetyl-CoA Carboxylase?

ATP + Acetyl-CoA + HCO3- (bicarbonate) → Malonly-CoA

What are the major steps of fatty acid synthesis? (7)

0 Formation of Malonyl-CoA

A Activation of ACP by Malonyl-CoA

1 Condensation of the malonyl and Acetyl groups (and release of CO2)

2 Reduction of keto group

3 Dehydration of hydroxyl group to ene

4 Reduction of bd with addition of H

5 The chain is transferred and the cycle continues

Where does fatty acid synthesis occur?

The cytosol

What’s the activator of Acetyl-CoA carboxylase

Citrate

What’s the inhibitor of Acetyl-CoA Carboxylase

Palmotyl-CoA or other long chain fatty acids

What’s the inhibitor of CAT1 (CPT1)

malonyl-CoA

What activates N-Acetylgkutamine Synthase (NAGs)

Arginine

What are the inhibitors of HMG-CoA Reductase

PKA

AMPK

Oxysterol

What reactions/Enzymes require PLP as a cofactor (3)

Aminotransferase

Glutathione-B-Synthase

Carboxylation RXNS in Neurotransmitter Synthesis

Where is glutamate dehydrogenase located

In the mitochondria

What’s the process of bulk degradation of cytoplasmic components

Autophagy

What amino acid is produced by skeletal muscles to detoxify ammonia

Alanine

(produced from PYR in the muscle tissue)

What does Glucagon Activate and Inactivate in Fatty Acid Metabolism

Glucagon Activates Hormone Sensitive Lipases (HSL)

Glucagon Inactivates Acetyl-CoA Carboxylase (ACC)

What does Insulin Activate and Inactivate in Fatty Acid Metabolism

Insulin Activates Acetyl-CoA Carboxylase (ACC)

Insulin Inactivates Hormone Sensitive Lipase (HSL)

What reduced cofactor is required in Fatty Acid Synthesis

NADPH

When are catecholamines released?

Released in response to emotional or physical stress

What is GABA

GABA is a major neurotransmitter INHIBITOR found in the CNS that reduces neural excitabiliy.

What is GABA synthesized from

GABA is synthesiszed from GLN in a PLP dependent carboxylation reaction

What are the Chatecholamines

Dopamine

Norepinephrine

Epinephrine

What neurotransmitter regulates mood, sleep, digestion, blood clotting and sexual desire?

Seratonin

When does (-) nitrogen balance occur?

Occurs when there are not enough AA in the body;

Disease state and starvation

When does (+) nitrogen balance occur?

When there is an increased incorporation of AA into the body

Growth, pregnancy, post-starvation, disease recovery

In what disease does Hyperammonemia Occur?

In orodic aciduria from UTD

In what disease does Severe Megaloblastic Anemia Occur

In Orodic Aciduria from a problem in Pyrimidine Synthesis

Can be from Orotidylate Decanoxylase/PLP defficency.

What is Bacterial ATCase inhibited by

CTP

What is Ribonucleotide reductase inhibited by?

dATP (feedback inhibition)

What is a CPS-II inhibitor?

UTP

What are glutamate dehydrogenase’s activators and inhiboters

Activators: ADP, GDP and free amino acids

Inhibiters: ATP, GTP, NADH

What are the essential amino acids?

Trp, Phe, Thr,

Val, Leu, Ile, Met

Lys, His

BH4 Tetrahydrobiopterin is required for what enzyme?

Phenylalanine Hydroxylase (creates TYR)