Exam 2: FA Synthesis Flashcards by Rachel Smith

Primary tissue of FA synthesis

Liver

How well did you know this?

Not at all

Perfectly

FA synthesis also occurs in the following tissues

Adipose tissue
Kidney
Mammary glands during lactation

How well did you know this?

Not at all

Perfectly

Synthesis of FA occurs in

Cytosol

How well did you know this?

Not at all

Perfectly

When isocitrate DH is inhibited by ATP, ____ accumulates

Citrate

How well did you know this?

Not at all

Perfectly

When citrate accumulates, it is exported to the

Cytosol

How well did you know this?

Not at all

Perfectly

High sugar forces glycolysis to make lots of ___ in the ___

ATP

Liver

How well did you know this?

Not at all

Perfectly

Once citrate is exported to cytosol, ____ used it to produce acetyl CoA

Citrate lyase

How well did you know this?

Not at all

Perfectly

After acetyl CoA is back in cytosol, ___ is created via _____

Malonyl CoA

Acetyl CoA carboxylase

How well did you know this?

Not at all

Perfectly

FA synthesis keeps adding ___ to a growing FA chain

Malonyl CoAs

How well did you know this?

Not at all

Perfectly

FA synthase is an ____ with multiple enzyme domains

Enzyme complex

How well did you know this?

Not at all

Perfectly

One portion of FA synthase is this molecule

ACP

How well did you know this?

Not at all

Perfectly

ACP stands for

Acyl Carrier protein

How well did you know this?

Not at all

Perfectly

ACP is similar to

CoA

How well did you know this?

Not at all

Perfectly

There is a terminal ___ group at the end of FAS

Thiol

How well did you know this?

Not at all

Perfectly

Process of ACP of FAS grabbing acetyl’s

ACP grabs acetyl
ACP transfers acetyl to holding site
ACP grabs malonyl
Acetyl and Malonyl combine
Ketone converted to alcohol
Water removed
Molecule reduced

How well did you know this?

Not at all

Perfectly

FAS steps

Condensation
Reduction
Dehydration
Reduction

How well did you know this?

Not at all

Perfectly

End product of FA synthesis

Palmitate (16:0)

How well did you know this?

Not at all

Perfectly

FAS uses ___ to reduce

NADPH

How well did you know this?

Not at all

Perfectly

NADPH is created in

Pentose Phosphate Pathway

How well did you know this?

Not at all

Perfectly

FA are ____ molecules

Highly reduced

How well did you know this?

Not at all

Perfectly

NADPH is created by this enzyme in the cytosol

Malic enzyme

How well did you know this?

Not at all

Perfectly

Release of the FA is accomplished by

Palmitoyl Thioesterase

Part of FAS complex

How well did you know this?

Not at all

Perfectly

Palmitate can be ____ and ___ by ____ and ___ (enzymes_

Elongated and desaturated

Elongases
Desaturases

How well did you know this?

Not at all

Perfectly

Humans cannot create double bonds beyond the ____ carbon

9th-10th C

How well did you know this?

Not at all

Perfectly

Conditions that stimulate FA synthesis

1. High energy charge 2. Lots of acetyl CoA 3. Lots of NADH and FADH2 4. Lots of citrate 5. Lots of sugar 6. Insulin

Degradation of FA to make ATP occurs in the

Mitochondria

Key enzymes in FA synthesis

Citrate lyase Acetyl CoA carboxylase FAS

In the cytosol, ____ releases acetyl CoA from citrate in preparation for FA synthesis

Citrate lyase

Eating lots of ___ stimulates fat synthesis

Sugar

GLUT2 Function

Transport glucose, galactose, and fructose out of intestine into liver

GLUT2 is ___ independent

Insulin

GLUT4 Function

Transport glucose into muscle and adipose tissue via facilitated diffusion

GLUT4 is stimulated by 2 things:

1. Insulin | 2. Low energy charge

About 90% of insulin-stimulated glucose uptake occurs in

Skeletal muscle

By adding a ___ to glucose, glucose concentration in muscle remains low and ___ keeps coming in

Phosphate Glucose

When muscle energy charge is low, G6P runs through...

Glycolysis Prep step Krebs

When muscle glycogen is low, G6P is converted to

Glycogen

Exercise stimulates accumulation of ___ in cell membrane for 1-2 hours afterwards

GLUT4

Glucokinase is stimulated by

Insulin | Fructose

Glucokinase is ___ by its product

NOT inhibited

___ has a lesser affinity for glucose

Glucokinase

If glucose and does not need to go through glycolysis and glycogen is full, high energy charge will

Inhibit PFK

Inhibition of PFK causes ____ to accumulate

G6P

G6P inhibites

Hexokinase

Inhibition of hexokinase causes ___ to accumulate

Glucose

Glucose accumulation stops flow from ___ to ____

Blood into muscle

Rate limiting step in FA synthesis

Acetyl CoA carboxylase

Stimulation of ACC

Citrate | Insulin

Inhibition of ACC

Malonyl CoA Palmitoyl CoA Epinephrine Glucagon

High calories increase synthesis of ____ via changes in transcription factor regulation

ACC

AMPK phosphorylates ACC, causing

Inactivation

Malonyl CoA inhibits

Carnitine acyl transferase I

Citrate inhibits

PFK1

___ is primary site of fructose disposal

Liver

___ and ___ are enzymes essential for fructose metabolism and are highly expressed in the ___

Fructokinase Triokinase Liver

___ and GLUT8 transport fructose into liver

GLUT2

____ has limited expression in muscle and adipose tissue

Triokinase

Small amounts of fructose cause the release of ___ from a regulatory protein

Glucokinase

Normally, F6P binds to GK regulatory protein and ____ is inhibited

Glucokinase

When F1P binds to regulatory protein, GK is set free and ___

Activated

Fructose skips the regulation of __

PFK

Fructose stimulates ___

Glucokinase

Fructose produces more ____ and ATP

Acetyl CoA

HSL is strongly inhibited by

Insulin

___ is elevated in type 2 diabetes

ATGL

___ is reduced in type 2 diabetes and heavily inhabited

HSL

HSL has 10 fold higher specific activity for ___ than ___

DAG TAG

Imbalance of ____ breakdown in obese individuals

TAG/DAG

When the cell overexpresses more ATGL, more ___ is produced

DAG

Insulin inhibits HSL, which normally likes to break down ___

DAG

DAG accumulates and activates ____

PKC