Fatty Acid Biosynthesis

Acetyl-CoA is the only

carbon precursor

FA biosynthesis uses

NADPH (from PPP) and ATP, CO₂, Biotin

FA Biosynthesis Chemistry is the

opposite of FA oxidation

FA Biosynthesis is built

tail to head

Ac-CoA moves to the cytosol by using the

Citrate-Malate Shuttle

Ac-CoA is made in the

mitchondria

Ac-CoA needs to be in the ___ for FA biosynthesis

Cytosol

Citrate is a ___

Ac-CoA Carrier

Citrate Malate Shuttle Pathway

Malate → OAA → Citrate →OAA + Ac-CoA (in cytosol) → Malate →Malate (in mitochondria) 

Citrate Shuttle refers to what process

FA Synthesis 

Citrate Malate brings __ from matrix to cytosol  

Ac-CoA

Citrate Malate brings Ac-CoA from ___ to ___

matrix to cytosol

PEP-Pyruvate Shuttle refers to what process

Gluconeogenesis 

PEP-Pyruvate brings __ into the matrix and ___ out to bypass through step 10 in glycolysis

pyruvate and PEP

PEP-Pyruvate shuttle brings pyruvate ___ and PEP ___ to bypass step 10 of glycolysis

into the matrix and out 

PEP-Pyruvate Shuttle’s role in Gluconeogenesis

Bypass step 10 of glycolysis 

Malate-Aspartate Shuttle refers to what process

Glycolysis 

Malate-Aspartate Shuttle moves _______in glycolysis from cytosol to matrix for ox phos

electrons from NADH

Malate-Aspartate Shuttle moves electrons from NADH in glycolysis from the ____ to ___ for oxidative phosphorylation

cytosol to the matrix

Malate-Aspartate Shuttle helps

Glycolysis and Oxidative Phosphorylation

Chemistry Steps of FA synthesis

Reduction, Dehydration, Reduction, Synthase

FA Synthesis starts with 

one Ac-CoA

The rest of the carbons are added as 

Malonyl-CoA

Malonyl CoA is made by

Acetyl-CoA Carboxylase

Malonyl CoA Reaction

CoA → Malonyl CoA

Cofactors: CO₂, ATP, Biotin

Enzyme: Ac-CoA Carboxylase 

Malonyl CoA Reaction Releases

ADP

Acetyl-CoA Carboxylase is similar to

Pyruvate Carboxylase

All regulation of FA biosynthesis occurs at 

Acetyl-CoA Carboxylase 

ACP

A protein that is important for the production of fat

ACP vs CoA usage

ACP for FA Synthesis 

CoA for FA breakdown

ACTP has a

S of cysteamine attached to a FA

FA Biosynthesis uses __ for each round

2 NADPH

FA Biosynthesis is ___ while FA Oxidation is

reductive, oxidative 

FA Biosynthesis occurs in the

cytosol

The Six Steps of FA Synthase Complex

1. Loading of first Ac-CoA onto KS (lose CoA)

2. Loading of Malonyl Group onto ACP (CoA)

3. Attachment of two carbons (lose CO₂)

4. Reduction (transfer of e⁻)

5. Dehydration (loss of H₂O)

6. Reduction (transfer of e⁻)

Loading of the First Acetyl onto KS loses

CoA

Loading of Malonyl Groups onto ACP loses

CoA

Attachment of two carbons loses

CO₂

Reduction occurs __ and involves the

twice, transfer of e⁻

Dehydration involves

loss of H₂O

We use ___ to make Malonyl-CoA

1 ATP

Palmitate

a 16 C FA

__ takes more energy

Synthesis

Ac-CoA Carboxylase is inhibited by 

FA-CoA (no futile cylcing)

CoA Carboxylase is activated by

Citrate and Insulin

• lots of Citrate ==> lots of Ac-CoA ==> want to store as FA

• Insulin wants to store as Fats, Glycogen

Malonyl-CoA inhibits

FA-CoA Synthetase 

(start of FA oxidation, no futile cycling)