Beta Oxidation II (Ch 30)

Question 1

An uncoupler does what?

Answer 1

seperates electron transport from ATP synthesis

Question 2

An uncoupler does what to the proton gradient? and making ATP ?

Answer 2

decreases; gets slower

Question 3

An uncoupler does what to the the rate of oxidative phosphorylation?

Answer 3

increases

Question 4

What happens to the rate of glycolysis under anaerobic conditions?

Question 5

Where does the first step of oxidation occur in the molecule in the beta oxidation spiral? what enzyme is used?

Answer 5

between the alpha and beta carbons; acyl coa dehydrogenase

Question 6

What happens in the alternative route of FA oxidatation in the peroxisome?

Answer 6

alpha or beta oxidation of Very Long chain fatty acids

Question 7

Why would a FA not get b oxidized in the mitochondria?

Answer 7

If it is not a LC FA, is xenobiotic with carboxyl group

Question 8

Peroxisome acyl coa synthetases recognize

Answer 8

VLCFA and phytanic acid (does it say lcfa because the chain gets shortened? ask)

Question 9

How is peroxisomal b oxidation different than mitochondrial b oxidation?

Answer 9

no carnitine, first e- acceptor is oxygen, regulate by substrate available or not

Question 10

What is the first step of peroxisomal b oxidation? (after the synthetase activated the VLCFA)

Answer 10

FAD oxidase transfers e- to O2-> H2O2 that is handlable in the peroxisome

Question 11

Oxidizing between carbons creates

Answer 11

a double bond

Question 12

What type of oxidation happensi n the ER?

Answer 12

omega (the end carbon) oxidation

Question 13

The second step in peroxisomal b oxidation

Answer 13

Adding water (hydration) to the double bond

Question 14

The third step in peroxisomal b oxidation

Answer 14

oxidation of the beta carbon to a ketone

Question 15

Any CoA derivative (SCFA CoA, MCFA, acetyl CoA, etc) is converted to carnitine derivatives in order to enter the mitochondria and finish oxidation, True or False?

Answer 15

TRUE

Question 16

Any CoA derivative (SCFA CoA, MCFA, acetyl CoA, etc) is converted to carnitine derivatives in the __ order to enter the mitochondria and finish oxidation. Which enzymes get used?

Answer 16

peroxisome; COT carnitine octanoyltransferase and CAT carnitine acetyl transferase

Question 17

You must complete oxidation to a SCFA in order to go from peroxisome->mitochondria- True or False?

Answer 17

FALSE- you can do partial oxidation (won’t get the max # of acetyl coAs)

Question 18

A single round of beta oxidation is enough for the oxidation of very long chain FA before entering mitochondria, True or False?

Answer 18

FALSE- multiple rounds happen until you get a MCFA or SCFA, and then those synthetases activate those FA’s

Question 19

How is peroxisomal beta oxidation regulated?

Answer 19

It is regulated by substrate availability

Question 20

What are the products(besides acetyl CoA) of peroxisomal beta oxidation?

Answer 20

NADH(n) and H2O2(n) which is hydrogen peroxide (normally dangerous but we ok since we are in this organelle that’s job is to purify)

Question 21

What happens to the peroxisomal NADH (n) product?

Answer 21

It will need a shuttle to go elsewhere, because it was NOT made in the mitochondria

Question 22

Herbivores eat plants, and the chlorophyll from them that gets turned into a product called ___ in their tissues. What else is this found in?

Answer 22

Phytanic acid; dairy products

Question 23

You cannot do beta oxidation on phytanic acid because __ . When does beta ox happen in the peroxisome besides the FAs (is phytanic acid a FA? ask,)

Answer 23

the beta carbon is occupied with a methyl ; after alpha oxidation pristanic acid is formed, and can do beta oxidation

Question 24

Why is phytanic acid dangerous

Answer 24

It is a neurotoxin

Question 25

All mammals make phytanic acid after eating plants, True or False?

Answer 25

FALSE- humans don't. only herbivores

Question 26

When pristanic acid makes products through beta oxidation, what are they?

Answer 26

some acetyl Coa, some propionyl coa, and 1 isobutryl coa

Question 27

When would ER oxidation be important?

Answer 27

When there are oxidation disorders, there are lots of FA that can't be broken down and ER oxidation is like a back up plan for them

Question 28

What enzyme is ER oxidation catalyzed by? What are its requirements?

Answer 28

ER oxidation is catalyzed by a mixed function oxidase; NADPH and O2

Question 29

When fatty acids are oxidized in the ER, what end they oxidized?

Answer 29

The methyl at the omega carbon is oxidized

Question 30

What enzymes are neededafter the mixed oxidase in ER oxidation?

Answer 30

alcohol dehydrogenase oxidizes, and next up is aldehyde dehydrogenase

Question 31

Very long chain acid accumulation is toxic,True or False?

Answer 31

True! but we won't talk about it

Question 32

What dietary therapy is helpful for those with Zellweger spectrum disorder? (ask about this!)

Answer 32

getting rid of beef, lamb, diary (why not mcfas and low fat?)

Question 33

What hormone regulates the amounts of free fatty acids available (they come from adipocytes)?

Answer 33

Hormone sensitive lipase

Question 34

What is acetyl coA turned into in the liver? Where do they go?

Answer 34

acetoacetate and beta hydroxybutyrate (both ketone bodies); into circulation and convert back to acetyl coa for TCA outside liver

Question 35

Would free fatty acids in the serum rise or fall the longer you go without food? Why?

Answer 35

The free fatty acid concentration rises; more breakdown of TAG in adipocytes

Question 36

As a fast progresses, __drops and ___ rises

Answer 36

glucose; fatty acids