Bioc Set 3 Ketone Bodies

Front 1

How is OAA made/regenerated in the cell?

Back 1

Glycolysis: Glucose --> 2 pyruvate
Pyruvate + ATP + CO2 --> Oxalo Acetate (pyruvate carboxylase)

or from Gluconeogenic AAs

Or from Propionyl CoA --> Succinate, which will then be converted into OAA VIA the Kreb Cycle

Can also be made from Lactate and glycerol

Front 2

What is the first step in the Krebs Cycle?

Back 2

Acetyl CoA ( 2C) condenses with Oxaloacetate(6C, OAA) +H2O to form Citrate + CoA

OAA + H20 + Acetyl-CoA---> Citrate + CoA

Front 3

What Happens to OAA in liver cells during extreme Starvation, or untreated diabetes?

Back 3

There is no regeneration of OAA and TCA Cycle cannot continue. The OAA in the liver is used to produce Glucose, which is then consumed, and the resulting pyruvate is pushed through the kreb cycle for Energy. No regen of OAA

Front 4

What happens to Acetyl CoA in the liver during Starvation, and a lack of OAA

Back 4

Acetyl CoAs are transformed into Ketone Bodies, blood soluble versions of Acetyl CoA

Front 5

What are the three types of Ketone Bodies made in the liver?

Back 5

Acetone

AcetoAcetate

D-B-Hydroxybutyrate

Front 6

What happens to Acetone when it is produced?

Back 6

exhaled

Front 7

Why can't the Brain use FAs?

Back 7

Because the FAs cannot fit through the Blood Brain Barrier (BBB), which is composed of tight junction endothelial cells.

Front 8

Where are Ketone Bodies produced?

Back 8

In the Mitochondrial Matrix of liver cells

Front 9

Where does the Liver export Glucose to?

Back 9

The Brain, Renal Cortex, Heart, Adipose tissue, Skeletal muscle

Front 10

Where does the liver export Ketone Bodies to?

Back 10

Brain, Heart, Skeletal muscle, renal Cortex (but not to Adipose tissue)

Front 11

Where do FAs from Adipose tissues get shipped to?

Back 11

Liver, Heart, Renal Cortex, Skeletal muscle (but not brain, can't pass the BBB)

Front 12

What enzyme catalyzes the condensation reaction of 2 Acetyl CoA --> Acetoacetyl-CoA

Back 12

Thiolase

Front 13

What enzyme catalyzes the reaction AcetoAcetyl-CoA ---> HMG-CoA

Back 13

HMG-CoA synthase

Front 14

What is the full name of the Molecule HMG-CoA?

Back 14

B-Hydroxy B-methylglutaryl CoA (co-enzyme A)

Front 15

What molecule Cleave HMG-CoA (B-hydroxy B-methylglutaryl CoA) into Aceto Acetate?

HMG-Coa --> AcetoAcetate + Acetyl-CoA

Back 15

HMG-CoA lyase.

Front 16

which enzyme catalyzes the reaction AcetoAcetate -->> acetone + Co2

Back 16

Acetoacetate decarboxylase

Front 17

which enzyme catalyzes the reaction Aceto-Acetate decarboxylase ---> D-B-Hydroxybutryate?

Back 17

D-B-hydroxybutyrate dehydrogenase

Front 18

Which has more Energy, D-B-Hydroxybutyrate, or AcetoAcetate, and why?

Back 18

D-B-Hydroxybutyrate because it is more reduced. NADH reduces Acetoacetate to form D-B-Hydroxybutyrate. This rxn is catalyzed by D-B-Hydroxybutyrate dehydrogenase.

Front 19

What determines whether Acetoacetate or D-B-Hydroxybutyrate is exported from the liver?

Back 19

The concentration of NADH in the cell. If [NADH]/[NAD+] <1, Acetoacetate will be predominantly made and exported.

Front 20

What happens when D-B-HydroxyButyrate arrives at extra hepatic tissues?

Back 20

it is oxidized to form acetoacete. Once acetotoacetate is made, it is catalyzed by B-KetoAcyl CoA transferase to form Acetoacyl-CoA. Aceto Acyl CoA is then used to produce two Acetyl-CoA, which will then be pumped into the kerb cycle to make ATP

Front 21

What is the enzyme that converts AcetoAcyl-CoA into 2 Acetyl CoAs?

Back 21

Thiolase (same one used in B-ox, and Ketone body synthesis)

Front 22

Why does the liver produce very low levels of B-KetoAcyl transferase

Back 22

This would create a futile cycle. If B-Ketoacyl Transferase was produced in the liver, every time acetoAcete is produced, it would be converted back into Acetoacetate-CoA.

Front 23

Which intermediate molecule is produced during the synthesis of Ketone bodies, but not during the catabolism of ketone bodies?

Back 23

HMG-CoA (B-Hydroxy B-Methylglutaryl-CoA)

Front 24

What is a negative effect of a prolonged increase is acetyl-CoA concentration as a result of prolonged starvation?

Back 24

Keto Acidosis. Ketone bodies are acidic, and if there is no OAAs, Acetyl CoA will build up, causing ketone bodies to be created, which will decrease the pH of the blood.