Lipolysis, beta oxidation, transamination, and oxidative deamination

What is the process of lipolysis, what is the end result? What enzymes are involved?

Lipolysis is the process of breaking apart a triacylglycerol into into it’s glycerol backbone and Fatty acid chains

The first Enzyme is Adipose Triglyceride Lipase (ATGL): The “starter”. It performs the first and rate-limiting step, removing the first fatty acid to convert a triacylglycerol into a diacylglycerol

The second enzyme is Hormone sensitive lipase (HSL): The “middleman”. While it can act on various fats, it’s primary role in this context is removing the second fatty acid, converting DAG into a monoacyglycerol (MAG)

The final enzyme in lipolysis is Monoacyglycerol (MAGL): the “finisher”. It removes the final fatty acid from the MAG, leaving your with one glycerol and the last FFA

Explain the process of Beta oxidation

When FFAs are floating around CoA (co-enzyme A) can attach to the alpha and beta carbons on a FFA (done by the enzyme Fatty acyl-CoA synthetase) and turns it into Fatty Acyl-CoA and then is split into multiple 2 Carbon Acetyl-CoA which can travel to the krebs cycle to produce energy

Glycerol can then become glucose through gluconeogenesis

Explain the process of Transamination

• First step in amino acid catabolism

• Instead of removing a nitrogen, the body simple moves it from an amino acid to a keto acid (a-ketogluterate)

  • Result: the original amino acid becomes a a-keto-acid (which can enter the krebs cycle) and the reciever becomes Glutamate

Explain the process of oxidative deamination

• Takes the glutamate produced during transamination and strips off the nitrogen enitrely

• Result: The nitrogen is released as amonia (NH3), hydrogen is stripped off for NADH (1 per glutamate), and a-ketogluterate is regenerated to pick up more nitrogen

  • since amonia is toxic, the body quickly sends it to the urea cycle to be converted into urea and excreted in the urine