Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/18

Click to flip

18 Cards in this Set

  • Front
  • Back
2 biggest processes in FA metabolism
fatty acid synthesis and
beta oxidation
Principles of biosynthesis
in cytoplasm
uses acyl carrier protein (ACP)
major enzyme is fatty acid synthase
Adds activated 2 C units from malonly ACP
Nadph is e- source
complete at palmitate C16
3 phases
1=get acetyl coA out of mito.
2=activate them by adding CO2 addition of acetyo and malonyl to ACP
3=condensation and reduction
Phase 1=transfer of Acetyl CoA to cytoplasm
1=OAA and Acetyl CoA combine to citrate
2=citrate goes through citrate transporter in inner membrane and out into cytosol
3=enzyme citrate lyase turns back to OAA and Acetyl CoA
4=NADPH formed in process
*this and pentose phosphate shunt are two main sources of NADPH*
Phase 2=
activation of Acetyl CoA
to malyonyl coA and transfer to ACP
1=Acetyl CoA carboxylase makes AcoA into malonyl CoA, uses ATP, HCO3-,and BIOTIN which adds C02
2=malonyl CoA ACP transcyclase take 3 malyonyl and adds to ACP(acyl carrier protein) to make malonyl ACP
3=Acetyl CoA added to ACP by Acetyl coA-ACP transcyclase to make Acetyl Acyl Carrier Protein (acetyl ACP)
Regulation of Acetyl Co A carboxylase
Hormonal
1=Insulin stimulates
2=glucagon inhibits
3=epinephrine inhibits

Allosteric
Citrate stimulates
Palmitoyl CoA inhibits
AMP inhibits

Local Control= binding of citrate to a pi thus inactive carboxylase will partially activate it
Phase 3=
Condensation and Reduction
Fatty Acid Synthase-7 enzymatic activities
Dimer w/3 domains
Major enzyme here


All the following steps are in this phase
Fatty Acid Synthase
First Domain/subunit
Substrate Entry and
Condensation unit
1=acetyl transferase accepts ACoA, transfers to Condensing Enzyme
2=malonyl transferase accepts malonly CoA, tansfers to ACP
3=Beta ketoacyl synthase=condensing enzyme

*ACP and CE come together and form a 4 carbon chain (C02 released) which is held in ACP site*
Fatty Acid
Second Domain/subunit
beta ketoacyl reductase reduces (takes H from NADPH leaves NAD)
beta hydroxy acyl dehydratse dehydrates
enoyl reductase reduces (takes H from NADPH leaves NAD)
Fatty Acid Synthase
Third Domain/subunit
thioesterase
recognizes when chain has grown to 16C and will chop it off
Role of mixed function oxidases
takes 2 substrates one fatty acid with double bond one without, adds them together and makes a bigger unsaturated fatty acid.
done by fatty acid acyl CoA desaturase
Elongation
in smooth er and mito.
addition of 2C units from Acetyl CoA to the fatty acid chain
adrenoleukodystrophy=cant oxidize long chains of sat. so feed long chains of unsat to compete
Omega nomenclature
start at opposite end of C00- functional group and count to first double bond and call omega
Essential fatty acids
we can't desat. past a double bond at position 9 so we need to uptake essential fatty acids with desaturation past C 9 to make important things like Arachidonic acid=signal mol.
Regulation of fatty acid oxidation
Malonly C0A=inhibits carnitine palmitoyl transferase CAT-1 which takes malonyl into matrixx
Synthesis of Ketone Bodies
Happens when you have too much Acetyl CoA
1=combine 2 ACoA (thiolase)
2=add 2 more ACoA, now a 6C (HMG CoA synthase)
3=Clip off 2C to be 4 C (HMG CoA lyase)
4=leaves with 4 C Acetoacetate (a ketone body)
5=can degrade into acetone and beta hydrowybuterate (other 2 ketone bodies)
Catabolism of ketone Bodies
1=start with beta hydroxybuterate
2=transfer a CoA from succinyl Co A to it (beta keto co A transferase)
3=cleave it and you get to Acetyl CoA

*organisms that have succinyl co a can use this mechanism to degrade ketone bodies for use, turn into Acety Co A for TCA cycle*
Regulation of Fatty Acid Oxidation
insert picture from lecute 62 add page 1