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Flashcards in Final: fatty acid oxidation Deck (27)
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1
Q

how can we fast for up to 2 weeks at a time?

A

we can store dietary fuels and break them down into ATP

2
Q

how do fatty acids generate ATP?

A

transfer of electrons in form of hydrogens to molecules can generate ATP

3
Q

where does fatty acid oxidation occur?

A

mitochondria of heart, liver, skeletal muscle cells

4
Q

where is fat stored?

A

in adipocytes as triglycerides

5
Q

triglyceride

A

3 fatty acids attached to glycerol

6
Q

what enzyme breaks down triglycerides?

A

Hormone sensitive lipase breaks triglycerides down into 3 fatty acids + glycerol

7
Q

starvation state

A

blood glucose decreases, pancreas secretes glucagon which increases activity of hormone sensitive lipase

8
Q

what hormone increases activity of hormone sensitive lipase?

A

increase in glucagon!

9
Q

once broken down by hormone sensitive lipase, what happens

A

fatty acids can leave fat cell and enter blood stream and bind to albumin

10
Q

albumin does what with fatty acids?

A

takes them to target cells, such as liver cells that can perform fatty acid oxidation
also makes them more soluble

11
Q

fatty acid oxidation getting into the cell

A

fatty acid dissociates from albumin and diffuses into cell

12
Q

carnitine shuttle purpose

A

carnitine can go back and forth through mitochondrial matrix to bring in more fatty acids

13
Q

carnitine shuttle regulation

A

malonyl-CoA (from fatty acid synthesis) can inhibit CAT1 and slow down fatty acid oxidation

14
Q

beta oxidation 1 cycle energy payoff

A

1 NADH, 1 FADH2, 1 acetyl-CoA

15
Q

where do NADH and FADH2 go?

A

ETC! bc they are electron rich
they can make ATP
1 NADH = 3 ATP
1 FADH2 = 2 ATP

16
Q

where does the 1 acetyl-CoA go?

A

citric acid cycle to yield NADH and FADH2 which then enter ETC and yield 12 ATP per acetyl-CoA

17
Q

1 palmitoyl-CoA yields

A

7 NADH
7 FADH2
8 acetyl-CoA
131 ATP - 2 ATP = 129 ATP

18
Q

what does propionyl-CoA get converted to

A

succinyl-CoA

a TCA cycle intermediate

19
Q

where does succinyl-CoA go (2 options)

A

1) enter TCA cycle and become oxaloacetate (extra oxaloacetate can be used in gluconeogenesis)
2) succinyl-CoA can be fully oxidized to CO2

20
Q

what triggers release of fatty acids from TAGs?

A

adrenaline, glucagon, and ACTH can activate lipases that release fatty acids from TAGs

21
Q

what happens to glycerol when fatty acids are broken down?

A

glycerol goes back to liver and can be converted to DHAP for gluconeogenesis

22
Q

how many ATP per NADH or FADH2

A
  1. 5 ATP per NADH

1. 5 ATP per FADH2

23
Q

fatty acid oxidation: anaerobic or aerobic?

A

aerobic: requires oxygen!

24
Q

when do we use more fatty acids as fuel

A

long duration = use more fats

higher intensity = more carbs as fuel

25
Q

ketone bodies

A

alternate source of fuel
produced in liver mitochondria (ketosis or ketogenesis)
can’t be used by liver!
transported in blood for use by other tissues

26
Q

ketone bodies unique facts

A

soluble form of fats
can cross blood-brain barrier (can be used by brain when glucose is unavailable)
EX: starvation/low carbs or Diabetes Mellitus

27
Q

ketoacidosis

A

caused by very high amounts of ketone bodies in blood
acidify blood, put strain on kidney
occurs during uncontrolled diabetes mellitus (without insulin, cells can’t use glucose in body)
fatty acids broken down and acetyl-CoA used to produce ketone bodies