BMS07-1031 Energy Release from Fat Flashcards
Name 3 common fatty acids and how many C they have
Linoleic acid
Liolenic acid
Stearic acid
All have 18 and 0 2 and 3 double bonds
Where do we break down triglycerides?
Adipose tissue
Describe the breakdown of triglycerides
Triacylglycerol lipase removes a FA
DAG lipase removes a FA
MAG lipase removes a FA
What 2 things activate lipase?
Adrenaline
Glucagon
How and where do FA travel to?
Bound to albumin to enter the plasms
Why do we want to make glycerol?
It is water soluble and can be taken up by all tissues to be used in glycolysis
Why can glycerol be fed into glycolysis?
Its only 3C so can be easily changed into pyruvate
How is glycerol used in glycolysis?
Converted to glucose in gluconeogenesis
What are intermediates of FA metabolism?
CoA thioesters
How are FA activated? Where does this occur?
Enzyme acyl-CoA synthetase
ATP used
CoASH added
To form fatty acyl-CoA in cytosol
What do we do with the fatty acyl CoA?
Transported from the cytosol into the mitochondria by…
Added to carnitine to form CoA and a carnitine molecule using the protein carnitine palmitoyl transferase 1
What happens after this?
Carnitine palmitoyl transferase 2 returns everything to its original form
Describe reaction 1
Fatty acyl CoA has 2 H removed by FAD using the enzyme acyl-CoA dehydrogenase to form enoyl-CoA hydratase
Describe reaction 2
Enoyl-CoA hydratase is used to convert enoyl-CoA to hydroxyacyl CoA by adding water
Describe reaction 3
Hydroxyacyl CoA is converted to beta ketoacyl CoA by adding 2H to NAD and using the enzyme hydroxyacyl CoA dehydrogenase
Describe reaction 4
Beta ketoacyl CoA is converted to fatty acyl CoA and acetyl CoA using the enzyme beta ketoacyl CoA tholase and adding CoA SH
How many C will have been lost after the process?
2
How do we metabolise odd numbered fats?
A carbon dioxide is added using ATP and propionyl CoA carboxylase enzyme
Methylmalonyl CoA mutase then converts this to succinyl CoA
When does ketogenesis occur?
When fat is the main source of energy e.g. in starvation and type 1 diabetes
What is converted to ketone bodies?
Acetyl coA
How are ketone bodies used?
Converted back to TCA intermediates like acetyl CoA and succinate
Why cant the liver use keton bodies?
It doesn’t have the enzymes to convert it to anything else so it would be pointless
