Fatty Acid Oxidation Flashcards
(30 cards)
Mention 3 different lipases
ATGL(adipose triglycerides lipase)
HSL(hormone sensitive lipase)
MGL(mono glyceride lipase)
Which of these three lipases is rate limiting enzyme?
HSL
Perilipin: definition? Function? How it’s activated?
- coat of protein & is found on the surface of lipid droplets in adipocyte
- prevent access of lipolytic enzymes, which hydrolyze triglycerides inside them
- by PKA that phosphorylates it, leading to conformational change of the surface & HSL access (FAs oxidation)
When triglyceride is hydrolyzed, where do its parts go?
- glycerol to liver (included in gluconeogenesis)
- 3 fatty acids to muscles (included in FAs oxidation in mitochondrial matrix)
What is the function of glycerol in liver?
It is converted to Glycerol 3 phosphate by glycerol kinase
Function of G-3-P?
- converted to DHAP (used in gluconeogenesis)
- to synthesize TGL when needed
How do FAs go to myocytes? Although it is hydrophobic !
By binding FAs with serum albumin
What is the purpose of Beta-oxidation?
ATP synthesis
Where does beta-oxidation take place?
Mitochondrial matrix
What is activation of FAs?
Where does activation of FAs occur?
- adding CoA to fatty acids = fatty Acyl CoA
- in cytoplasm
How many ATP used in FA activation?
2 ATP
How many reaction occurs to transport Fatty Acyl CoA from muscle’s cytoplasm to mitochondria?
3 enzymatic reactions
CAT1, carnitine translocase, CAT2
From where do CAT1 bring carnitine to be replaced with CoA in fatty Acyl CoA?
From mitochondrial matrix
Function of carnitine translocase?
- transporting carnitineAcyl from mitochondrial space to mitochondrial matrix
- transporting the free carnitine from mitochondrial matrix to mitochondrial space to be added to fatty Acyl to make carnitineAcyl + free CoA
Function of CAT2?
باختصار يرجع كلٍ لأصله وينتج لي
Fatty Acyl CoA + free carnitine
What is carnitine shuttle?
The transport of fatty Acyl CoA from myocyte’s cytoplasm to mitochondrial matrix
Which is the rate limiting step for beta-oxidation?
Carnitine shuttle
What rate limits carnitine shuttle?
High level of Malonyl CoA
- if it’s high: FA synthesis occur
- if it’s low: FA oxidation occur
Fatty acid oxidation always occur between
Alpha and beta carbon of fatty Acyl CoA
What are the products of 1 cycle (first cycle) of oxidation of palmitic acid (16C)?
1 Myristoyl (14C)
1 Acetyl CoA (2C)
1 NADH
1 FADH2
How many ATP used to convert propoinyl CoA to mathylmalonyl CoA?
1 ATP
Which vitamin is involved in conversion of propionyl CoA to D-methylmalonyl CoA? Which is required to carboxylaze odd carbon?
Biotin
Which vitamin is involved in conversion of L-methylomalonyl CoA to succinyl CoA? Which is required to oxidize odd C?
Coenzyme of vitamin B12 (deoxyadenosyl cobalamin)
- Which molecule is converted to malonyl CoA?
- By which enzyme?
- why ?
1- Acetyl CoA
2- ACC (Acetyl CoA carboxylase)
3- لأن Maloney CoA مسؤول عن FA synthesis,
فكل ما يزيد Malonyl CoA راح يصير FA synthesis ويتثبط FA oxidation.
