IBS 2 EXAM 1

What is the carrier for the transport of fatty acyl coa into the mitochondrion?

Carnitine

what is the subcellular location of CPT 1

outer mitochondrial membrane

what is the function of CPT1

to move fatty acyl group from CoA onto Carnatine.

what is the subcellular location of CPT 2?

Inner mitochondrial membrane

what is the function of CPT 2?

moves fatty acyl group from carnitine back to CoA to b-oxidation can occur

what does chronic valproate treatment do?

reduces b-oxidation by depleting carnitine

What are the 3 major products of mitochondrial-B-oxidation?

Acetyl-CoA, NADH, FADH₂

What are the 2 dehydrogenases in mitochondrial B-oxidation

Acyl-CoA dehydrogenase and β-Hydroxy-acyl CoA dehydrogenase

what enzyme produces NADH during b-oxidation?

β-Hydroxyacyl-CoA dehydrogenase

what enzyme produces FADH2 during b-oxidation?

Acyl-CoA dehydrogenase

what do peroxisomes do when oxidizing long chain fatty acids?

starts breaking them down

what does the mitochondia do when oxidizing long chain fatty acids?

finishes the breaking down

what do Peroxisomes produce?

H2O2 (hydrogenperoxide)

what does mitochondria produce in oxidation?

FADH2

what enzyme is responsible for lipolysis?

Hormone-sensitive lipase (HSL)

what is the metabolite that inhibits CPT 1?

Malonyl-CoA

what are the 2 species of ketone bodies?

Acetoacetate and β-Hydroxybutyrate

what is the common precursor for ketone bodies?

Acetyl-CoA

what is the organ for ketogenesis

liver

what is the sub-cellular location of ketogenesis

Mitochondrial matrix of liver cells

what is the significance of ketone body synthesis and utilization?

to be a alternate energy source when fasted and spare glucose

what happens during diabetic ketoacidosis (DKA).

Insulin deficiency → excessive ketone production → metabolic acidosis

how are bile salts recycled?

bile salts digest fat then 95% go back to the liver

how does recycling bile salts affect medications?

certain medications are also recycled keeping them in the body longer.

what are the 2 major components of plasma lipoprotiens?

lipids and apoproteins

what is the plasma lipoprotien structure?

outside- apoprotiens, phospholipids, and free cholestrol

inside-tryglycerides and cholestryl esters

what are plasma lipidprotiens 2 functions?

Lipid transport and lipid metabolism

what is the major lipid component of newly formed chylomicron (nascent)?

triglycerides, (TG)

What is the major apoprotein found on a newly formed (nascent) chylomicron?

ApoB-48

Which lipoprotein donates ApoCII and ApoE to a nascent chylomicron so it can mature

HDL

A nascent chylomicron becomes mature after receiving which TWO apoproteins from HDL

ApoCII and ApoE

Which enzyme is responsible for breaking down triglycerides in circulating chylomicrons?

Lipoprotein lipase

what are the two tissue locations where LPL is found on capillary endothelial surfaces.

Muscle and adipose tissue

Which apoprotein activates lipoprotein lipase (LPL) so it can break down triglycerides

ApoCII

After most triglycerides have been removed, the chylomicron becomes a chylomicron remnant.

Which apoprotein helps the liver recognize and take up that remnant

ApoE

Which two tissues are primarily involved in fatty acid synthesis?

Liver and adipose tissue

Where inside the cell does fatty acid synthesis occur?

Cytosol

Which molecule carries acetyl-CoA's carbon units from the mitochondria into the cytosol

Citrate

Which enzyme converts citrate back into acetyl-CoA in the cytosol?

ATP citrate lyase

What is the energy requirement for ATP citrate lyase to regenerate acetyl-CoA

ATP

Which enzyme is the rate-limiting enzyme of fatty acid synthesis

Acetyl-CoA carboxylase

What reaction does acetyl-CoA carboxylase catalyze?

Acetyl-CoA → Malonyl-CoA

What does acetyl-CoA carboxylase require to make malonyl-coa

ATP

Which multi-enzyme complex is responsible for fatty acid synthesis?

Fatty acid synthase

Which molecule supplies the two-carbon units used to extend the fatty acid chain

Malonyl-CoA

Which molecule provides the reducing power needed for fatty acid synthesis?

NADPH

Which two apoproteins does HDL donate to VLDL during maturation?

ApoC-II and ApoE

what is the main lipid of VLDL?

triglycerides

where is VLDL made?

Liver

what apoprotein does VLDL have originally?

ApoB-100

what is the main hormone of anabolism?

insulin

what is the main hormones of catabolism?

Glucagon, epinephrine, cortisol

what does anabolism do to blood glucose?

decrease

what does catabolism do to blood glucose?

increase

anabolism is active during?

fed state

catabolism is active during?

fasting/rest

Which molecule signals low cellular energy and activates AMPK?

AMP

How does AMPK inhibit acetyl-CoA carboxylase (ACC)?

It phosphorylates and inactivates ACC.

When insulin is released after eating, how does it reactivate acetyl-CoA carboxylase (ACC)?

It activates a phosphatase that removes the phosphate from ACC.

Which molecule switches metabolism toward glycolysis by activating PFK-1?

Fructose 2,6-bisphosphate

Which enzyme produces fructose 2,6-bisphosphate from fructose 6-phosphate?

PFK-2

what happens to PFK-2 when insulin is released

PFK-2 is dephosphorylated and activated.

During fasting, glucagon is released. What happens to PFK-2 and F2,6-BP in the liver?

PFK-2 is phosphorylated and inactivated, decreasing F2,6-BP.

During fasting, which enzyme is activated to help break down stored triglycerides in adipose tissue?

Hormone-sensitive lipase (HSL)

How does glucagon activate HSL?

Glucagon activates PKA, which phosphorylates HSL