Beta Oxidation II (Ch 30) Flashcards
An uncoupler does what?
seperates electron transport from ATP synthesis
An uncoupler does what to the proton gradient? and making ATP ?
decreases; gets slower
An uncoupler does what to the the rate of oxidative phosphorylation?
increases
What happens to the rate of glycolysis under anaerobic conditions?
Where does the first step of oxidation occur in the molecule in the beta oxidation spiral? what enzyme is used?
between the alpha and beta carbons; acyl coa dehydrogenase
What happens in the alternative route of FA oxidatation in the peroxisome?
alpha or beta oxidation of Very Long chain fatty acids
Why would a FA not get b oxidized in the mitochondria?
If it is not a LC FA, is xenobiotic with carboxyl group
Peroxisome acyl coa synthetases recognize
VLCFA and phytanic acid (does it say lcfa because the chain gets shortened? ask)
How is peroxisomal b oxidation different than mitochondrial b oxidation?
no carnitine, first e- acceptor is oxygen, regulate by substrate available or not
What is the first step of peroxisomal b oxidation? (after the synthetase activated the VLCFA)
FAD oxidase transfers e- to O2-> H2O2 that is handlable in the peroxisome
Oxidizing between carbons creates
a double bond
What type of oxidation happensi n the ER?
omega (the end carbon) oxidation
The second step in peroxisomal b oxidation
Adding water (hydration) to the double bond
The third step in peroxisomal b oxidation
oxidation of the beta carbon to a ketone
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?
TRUE
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?
peroxisome; COT carnitine octanoyltransferase and CAT carnitine acetyl transferase
You must complete oxidation to a SCFA in order to go from peroxisome->mitochondria- True or False?
FALSE- you can do partial oxidation (won’t get the max # of acetyl coAs)
A single round of beta oxidation is enough for the oxidation of very long chain FA before entering mitochondria, True or False?
FALSE- multiple rounds happen until you get a MCFA or SCFA, and then those synthetases activate those FA’s
How is peroxisomal beta oxidation regulated?
It is regulated by substrate availability
What are the products(besides acetyl CoA) of peroxisomal beta oxidation?
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)
What happens to the peroxisomal NADH (n) product?
It will need a shuttle to go elsewhere, because it was NOT made in the mitochondria
Herbivores eat plants, and the chlorophyll from them that gets turned into a product called ___ in their tissues. What else is this found in?
Phytanic acid; dairy products
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,)
the beta carbon is occupied with a methyl ; after alpha oxidation pristanic acid is formed, and can do beta oxidation
Why is phytanic acid dangerous
It is a neurotoxin
All mammals make phytanic acid after eating plants, True or False?
FALSE- humans don’t. only herbivores
When pristanic acid makes products through beta oxidation, what are they?
some acetyl Coa, some propionyl coa, and 1 isobutryl coa
When would ER oxidation be important?
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
What enzyme is ER oxidation catalyzed by? What are its requirements?
ER oxidation is catalyzed by a mixed function oxidase; NADPH and O2
When fatty acids are oxidized in the ER, what end they oxidized?
The methyl at the omega carbon is oxidized
What enzymes are neededafter the mixed oxidase in ER oxidation?
alcohol dehydrogenase oxidizes, and next up is aldehyde dehydrogenase
Very long chain acid accumulation is toxic,True or False?
True! but we won’t talk about it
What dietary therapy is helpful for those with Zellweger spectrum disorder? (ask about this!)
getting rid of beef, lamb, diary (why not mcfas and low fat?)
What hormone regulates the amounts of free fatty acids available (they come from adipocytes)?
Hormone sensitive lipase
What is acetyl coA turned into in the liver? Where do they go?
acetoacetate and beta hydroxybutyrate (both ketone bodies); into circulation and convert back to acetyl coa for TCA outside liver
Would free fatty acids in the serum rise or fall the longer you go without food? Why?
The free fatty acid concentration rises; more breakdown of TAG in adipocytes
As a fast progresses, __drops and ___ rises
glucose; fatty acids
