FA Degredation Flashcards
What types of FA’s do not require a carrier protein?
Short and medium FA’s can diffuse into mito.
What are the four enzymes in the cartitine shuttle?
Fatty Acyl CoA Synthetase
Carnitine palmitoyltransferase I
Carnitine-acylcarnitine translocase
Carnitine palmitoyltransferase II
What are the four steps to FA degredation?
- Oxidation - Acyl CoA Dehydrogenase (ACAD)
- Hydration - Enoyl CoA Dehydratase
- Oxidation - 3-Hydoxyacyl CoA Dehydrogenase:
- Thiolysis - Acetyl CoA Acetyltransferase (b-keto
thiolase) aka cleavage of Acetyl Co A
If have an odd number of FA’s how do you degrade?
Same till 3 Carbon:: proponyl Co A then Propionyl CoA Carboxylase adds a carbon to make Methylmalonate Co A, mutase to Succnyl Co A enters CAC
What are the extra steps to deal with unsaturated FA’s?
Have to use an Reductase (enol Co A isomerase) and Isomerase (enol Co A reductase)
What are some differences associated with VLCFA and peroxiosomal degredation?
- First step uses: acyl-CoA oxidase
- NADH oxidized cannot be re-oxidized
- Peroxisomal carnitine acyltransferase used for transport
- Peroxisomal β-ketothiolase has altered substrate specificity
MCFA deficency
Caused by autosomal recessive
The excess MCFA’s causes issues with urea cycle in liver so buildup of Ammonia poisonous
Leads to secondary carnitine deficiency by excretion of CA carnitine in urine
Where is the only place Ketone bodies are made? What is the purpose?
Liver; purpose is to provide energy for peripheral tissues in fasting and starvation
Fasting time and the energy source used
within the day glycogen broken to glucose
Day 1 TAG broken down
Day 3 ketone bodies produced and muscles broken
Glycerol and glucogenic AA’s used in gluconeogenesis
1-2 weeks brain use ketone bodies
2-3 months TAG used up proteins main source
Physiological ketosis vs Pathological ketoacidosis
Physiological due mild/moderate increase in ketone bodies
Pathological ketoacidosis when glucagon/Insulin ratio favors FA breakdown
