16. Fat Metabolism Flashcards
What is fat metabolism also known as?
b-oxidation
What is removed during the metabolism of a fatty acid?
2C fragments
What energy-rich sources are produce directly?
FADH2 and NADH
What is the first step to ensuring the metabolism of a fat molecule?
TAG -> FFA
Where does fat metabolism occur in the cell?
Forms acetyl coA in the cytoplasm, transferred into mitochondrial matrix
What enzyme catalyses the initial reaction?
Acyl CoA synthetase
Explain the significance of the initial reaction
Ensures the compound has a CoA to fix the compound in the cytoplasm
How do long chain acyl CoA’s enter the mitochondrial matrix given that CoA compounds can’t directly enter?
CAT-1 outside the mitochondria
Acyl CoA becomes Acyl Carnitine then allowed into mitochondria
What happens in response the Acyl CoA entering the mitochondria?
CAT-2 cleaves molecule at carnitine end of Acyl Carnitine after entry into mitochondria
Re-adds CoA to the Acyl molecule
Carnitine recycled
What kind of carrier is CAT?
Translocase
How is CAT-1 regulated?
Malonyl CoA and insulin
What is formed when carbohydrates are lacking?
Ketones
What happens when there is an accumulation of ketones?
Ketoacidosis; diabetes; trauma; starvation
Give examples of ketone bodies that accumulate as a result of lack of carbohydrates
Acetoacetic acid, b-hydroxybutyric acid, acetone
The build up of which products disturbs the acid-base balance?
AA acid and b-hydroxybutyric acid
What is ketoacidosis accompanied by in diabetics?
Insulin deficiency, hyperglycaemia and dehydration
LAck of insulin stops glucose absorption and can cause ketone body production; what is the result of hyperglycaemia?
Glucose overloading kidneys and spilling into urine
How does dehydration exacerbate ketoacidosis?
Osmotic movement into urine
Give and overview of Medium Chain Acyl CoA Dehydrogenase Deficiency
Blocks oxidation of fatty acyl CoA
Can’t produce sufficient acetyl CoA and in turn, enough ATP
Therefore, unable to compensate for hypoglycaemia
What kind of genetic disorder is MCADD?
Autosomal recessive
How is MCADD treated?
High carb, low fat diet
At what position does Lysine convert and to what?
304 - to Glutamic Acid
