Final: fatty acid oxidation Flashcards
how can we fast for up to 2 weeks at a time?
we can store dietary fuels and break them down into ATP
how do fatty acids generate ATP?
transfer of electrons in form of hydrogens to molecules can generate ATP
where does fatty acid oxidation occur?
mitochondria of heart, liver, skeletal muscle cells
where is fat stored?
in adipocytes as triglycerides
triglyceride
3 fatty acids attached to glycerol
what enzyme breaks down triglycerides?
Hormone sensitive lipase breaks triglycerides down into 3 fatty acids + glycerol
starvation state
blood glucose decreases, pancreas secretes glucagon which increases activity of hormone sensitive lipase
what hormone increases activity of hormone sensitive lipase?
increase in glucagon!
once broken down by hormone sensitive lipase, what happens
fatty acids can leave fat cell and enter blood stream and bind to albumin
albumin does what with fatty acids?
takes them to target cells, such as liver cells that can perform fatty acid oxidation
also makes them more soluble
fatty acid oxidation getting into the cell
fatty acid dissociates from albumin and diffuses into cell
carnitine shuttle purpose
carnitine can go back and forth through mitochondrial matrix to bring in more fatty acids
carnitine shuttle regulation
malonyl-CoA (from fatty acid synthesis) can inhibit CAT1 and slow down fatty acid oxidation
beta oxidation 1 cycle energy payoff
1 NADH, 1 FADH2, 1 acetyl-CoA
where do NADH and FADH2 go?
ETC! bc they are electron rich
they can make ATP
1 NADH = 3 ATP
1 FADH2 = 2 ATP
where does the 1 acetyl-CoA go?
citric acid cycle to yield NADH and FADH2 which then enter ETC and yield 12 ATP per acetyl-CoA
1 palmitoyl-CoA yields
7 NADH
7 FADH2
8 acetyl-CoA
131 ATP - 2 ATP = 129 ATP
what does propionyl-CoA get converted to
succinyl-CoA
a TCA cycle intermediate
where does succinyl-CoA go (2 options)
1) enter TCA cycle and become oxaloacetate (extra oxaloacetate can be used in gluconeogenesis)
2) succinyl-CoA can be fully oxidized to CO2
what triggers release of fatty acids from TAGs?
adrenaline, glucagon, and ACTH can activate lipases that release fatty acids from TAGs
what happens to glycerol when fatty acids are broken down?
glycerol goes back to liver and can be converted to DHAP for gluconeogenesis
how many ATP per NADH or FADH2
- 5 ATP per NADH
1. 5 ATP per FADH2
fatty acid oxidation: anaerobic or aerobic?
aerobic: requires oxygen!
when do we use more fatty acids as fuel
long duration = use more fats
higher intensity = more carbs as fuel
