fatty acids

Flashcards on Fatty Acids and Lipid Metabolism

Fatty Acids

Fuel molecules, building blocks of phospholipids and glycolipids, role in covalent modifications, derivatives serve as hormones and intracellular messengers

Triacylglycerols

Uncharged esters of fatty acids with glycerol, stored in adipose tissue and muscle

Dietary Lipids

Digested by pancreatic lipases

Bile Acids

Amphipathic molecules that facilitate lipid digestion by lipases, made from cholesterol secreted by the gallbladder

Chylomicrons

Lipoprotein transport particles made of new triacylglycerols with proteins, phospholipids, and cholesterol on the surface

FATPs

Transport free fatty acids into the membrane

FABPs

Bind fatty acids to smooth ER for resynthesis of triacylglycerol

Mobilization (Stage 1 of fatty acid processing)

Conversion of triacylglycerol to fatty acids in adipose tissue

Lipases

Intestinal enzymes that degrade triacylglycerols to free fatty acids and monoacylglycerols, secreted by the pancreas

Colipases

Proteins that bind lipases to particles for degradation in the pancreas

Fatty Acid Oxidation (Beta Oxidation)

Generates acetyl CoA, NADH, and FADH2 during fatty acid metabolism

Ketone Bodies

Fuel source from fats, formed in the liver and used for peripheral tissues, water soluble and transportable

Fatty Acid Synthase (FAS)

Enzyme in liver and adipose tissue for synthesizing fatty acids, active during embryonic development and lactation

Citrate Shuttle

Transports acetyl groups from mitochondria to cytoplasm for fatty acid synthesis

Acetyl CoA Carboxylase (ACC)

Enzyme catalyzing the committed step of fatty acid synthesis – the production of malonyl CoA

Malonyl CoA

Inhibits carnitine acyltransferase 1, preventing entry of fatty acyl CoAs into the matrix

Glucagon and Epinephrine

Inhibit both ACCs by increasing AMPK activity (inhibits fatty acid synthesis)

Insulin

Activates ACCs by enhancing dephosphorylation and inactivating AMPK, promoting fatty acid synthesis

AMPK

Activated by AMP and inhibited by ATP