Lipid Metabolism Lecture Notes

Fill-in-the-blank flashcards covering key concepts, enzymes, pathways, and regulatory points of lipid metabolism.

The process of breaking down stored triacylglycerols into free fatty acids is called __.

Lipolysis

Hormone-stimulated lipolysis in adipocytes is initiated by activation of __ cyclase.

Adenylate

The carrier molecule that transports activated long-chain fatty acids into the mitochondrial matrix is __.

Carnitine

Carnitine acyltransferase I is located on the __ mitochondrial membrane.

Outer

β-Oxidation shortens a fatty acyl-CoA by __ carbons per cycle.

Two

Each round of β-oxidation produces one molecule of FADH₂, NADH, and __.

Acetyl-CoA

Activation of a fatty acid requires the hydrolysis of one molecule of __ to AMP and PPᵢ.

ATP

The enzyme that catalyzes the first oxidation step of β-oxidation is acyl-CoA __.

Dehydrogenase

Odd-chain fatty acids yield __-CoA in their final β-oxidation cycle.

Propionyl

Propionyl-CoA is ultimately converted to __-CoA, an intermediate of the TCA cycle.

Succinyl

When oxaloacetate is low, excess acetyl-CoA in the liver is converted to __ bodies.

Ketone

The fruity odor on the breath of uncontrolled diabetics is due to the volatile ketone __.

Acetone

Fatty acid synthesis occurs primarily in the __ of animal cells.

Cytosol

The enzyme that commits acetyl-CoA to fatty acid biosynthesis is acetyl-CoA __.

Carboxylase

The cofactor that carries the growing fatty acyl chain during synthesis is __.

ACP

The two-carbon donor in fatty acid synthesis is __-CoA.

Malonyl

Reducing power for fatty acid synthesis is supplied by __.

NADPH

Fatty acid synthesis stops when the chain reaches __ carbons, forming palmitate.

Sixteen (16)

β-Oxidation occurs in the __, whereas fatty acid synthesis occurs in the cytosol.

Mitochondrial matrix

During lipolysis, fatty acids travel in the bloodstream bound to serum __.

Albumin

Chylomicrons are lipoproteins that primarily transport __ triacylglycerols.

Dietary

Very-low-density lipoproteins (VLDL) carry __ triacylglycerols from the liver to tissues.

Endogenous

Low-density lipoprotein (LDL) is the major blood carrier of __.

Cholesterol

High-density lipoprotein (HDL) participates in __ cholesterol transport.

Reverse

Omega-3 fatty acids are associated with slowing the development of __ diseases.

Cardiovascular

The energy yield from complete oxidation of one molecule of palmitate is approximately __ ATP.

129

Formation of malonyl-CoA during fatty acid synthesis requires the vitamin-derived cofactor __.

Biotin

During β-oxidation of unsaturated fatty acids, the acyl-CoA __ step is skipped, yielding less ATP.

Dehydrogenase

The four repeating reactions of β-oxidation are oxidation, hydration, oxidation, and __.

Thiolysis

Acetyl-CoA produced in β-oxidation enters the __ cycle for complete oxidation.

Citric acid (TCA)

In adipocytes, hormone-activated protein kinase phosphorylates and activates __ lipase.

Triacylglycerol

In fatty acid synthesis, the condensation reaction is catalyzed by β-ketoacyl-ACP __.

Synthase

Transport of citrate from the mitochondrion to the cytosol provides cytosolic __-CoA for fatty acid synthesis.

Acetyl

The double bonds in most natural fatty acids are of the __ configuration.

Cis

Saturated fatty acids tend to raise blood levels of __ cholesterol.

LDL

The glucocorticoid synthesized from cholesterol that regulates metabolism is __.

Cortisol

Fatty acid synthase in mammals is organized as a single __ enzyme complex.

Multienzyme

Removal of water from β-hydroxybutyryl-ACP produces __-ACP.

Crotonyl

The enzyme that reduces crotonyl-ACP to butyryl-ACP uses __ as electron donor.

NADPH

During the carnitine shuttle, acyl-carnitine crosses the inner mitochondrial membrane via a __.

Translocase

Malonyl-CoA inhibits carnitine __, preventing simultaneous synthesis and degradation.

Acyltransferase I

Lipogenesis is favored when the diet is low in fat and high in __.

Carbohydrate

Attachment of fatty acids to proteins produces __ that direct them to membranes.

Lipoproteins

The β-hydroxyacyl intermediates in fatty acid synthesis have the __ stereochemical configuration.

D

The β-hydroxyacyl intermediates in β-oxidation have the __ configuration.

L