NINJA NERD LIPIDS - MOBILISATION, ACTIVATION, BETA OXIDATION

where are fats stored

within tissue cells - adipose

what is the mobilisation of triacylglycerols

the breakdown of triacylglycerols into glycerol and fatty acids

when does mobilisation occur

in the fasting state when blood glucose levels are low

what happens when the blood glucose levels are low

alpha cells in the pancreas release a hormone called glucagon

epinephrine and norepinephrine is also released

MOBILISATION STEP 1

The hormones bind to GPCR which activates adenelate cyclase

cAMP is then produced which activates PKA

MOBILISATION STEP 2

PKA phosphorylates perilipin and CGI dissociates

MOBILISATION STEP 3

CGI activates adipose triglyceride lipase - cuts the ester bond and releases a fatty acid

MOBILISATION STEP 4

Hormone sensitive lipase cuts the diacylglycerol and another FFA is released

MOBILISATION STEP 5

Monoglyceride lipase cuts final ester bond - glycerol and last FFA are released

what happens to the FFA

they bind to albumin and are released into the blood

what happens to glycerol

transported into the blood where it can be taken up into the liver and converted to glucose through gluconeogenesis

what inhibits this process

insulin

ACTIVATION STEP 1

FFA enters the cell and is acted on by fatty acyl synthetase

gets converted into fatty acyl coA so that it cant escape cell

ACTIVATION STEP 2

Carnitine acyl transferase I combines carnitine with fatty acyl coA → fatty acyl carnitine which enters the mitochondria

ACTIVATION STEP 3

Carnitine acyl transferase II adds coA back on → fatty acyl coA

We lose the carnitine which can get recycled

what inhibits this process

malonyl coA

BETA OXIDATION STEP 1

Acyl dehydrogenase converts fatty acyl coA → trans delta 2 enolcoA

FAD → FADH2

B OX STEP 2

Enol coA hydratase adds water and converts

trans delta 2 enolcoA → L-3 hydroxyacylcoA

B OX STEP 3

L3 hydroxyacylcoA hydrolase converts

L-3 hydroxyacylcoA → 3-ketoacyl coA

NAD → NADH

B OX STEP 4

Beta-ketothiolase cleaves bond between alpha and beta carbon

we get acetyl coA and acyl coA

what can happen to acetyl coA

go into kerbs cycle

what does each round of beta ox generate

acetyl coA

NADH

FADH2

How many ATP does each of those molecules form

NADH = 2.5

FADH2 = 1.5

Acetyl CoA = 10