Fa Synthesis
Compiled By Simon Mwangi
Edition: 2024/25
, Science | Biochemistry I of IV pages
1. In humans, the ___ is the main site for FA synthesis
liver
note: other sites include: kidney, brain, lung, mammary gland, and adipose
2. The process of FA synthesis occurs in what part of the cell?
cytoplasm
3. FAs are synthesized from 2 carbon units (acetyl-CoA). ___ is the main source of the acetyl-CoA, with some
glucose; AAs
note: other cofactors/substrates include: NADPH, ATP, biotin, and HCO3-
4. The process of using acetyl CoA to produce FA in the cytosol requires two important enzymes. What are
acetyl CoA carboxylase
2. FA synthase
5. When glucose is plentiful, glycolysis in the liver will produce excess ___ which enters mitochondria and
pyruvate; acetyl-CoA
note: citrate, which is not further metabolized by the TCA can exit the mitochondria
6. In the cytosol, citrate is the substrate for ATP citrate lyase. What does this enzyme do? What does it
citrate is split back to oxaloacetate and acetyl-CoA
ATP is required
note: this enzyme is inducible
7. Cytosolic malate dehydrogenase reduces ___ to malate
OAA
8. What does the Malic enzyme do?
converts malate to pyruvate
produces NADPH which is necessary for FA synthesis
note: this enzyme is inducible
9. Acetyl-CoA carboxylase catalyzes the reaction producing ___-___ from acetyl-CoA
malonyl-CoA
10. Acetyl-CoA carboxylase requires ___ and is the rate-limiting enzyme of ___ ___
biotin; FA synthesis
11. Acetyl-CoA carboxylase is the regulated step of FA synthesis. It exists as either inactive ___ __ or as
proteomeric dimers; polymers
12. Acetyl-CoA carboxylase is stimulated by what? inhibited by what?
stimulated by citrate (feed forward)
inhibited by long-chain fatty acyl-CoA (feed back)
13. Acetyl-CoA carboxylase is also controlled by phosphorylation/dephosphorylation. True or false?
Biochemistry 2024/25 Edition