Lipids Flashcards
L1: ______ is the enzyme in the rate-limiting step of cholesterol synthesis.
HMG CoA reductase
L1: Acetyl CoA is transported from the mitochondrion to the cytosol in fatty acid synthesis by conversion to _______.
Citrate
L1: At mild to moderate exercise, _____ provides the primary source of energy for ATP synthesis.
Fat
L1: During vigorous exercise, _____ provides the primary source of energy for ATP synthesis.
Carbohydrates
L1: Geranyl pyrophosphate, farnesyl pyrophosphate, and squalene are intermediates in synthesis of _____.
Cholesterol
L1: In order to be transported into the mitochondria for beta oxidation, fatty acyl CoA is conjugated to ______.
Carnitine
L1: The rate limiting enzyme in fatty acid breakdown is _______.
Carnitine Palmitoyl Transferase 1 (CPT1)
L1: What % of caloric intake is accounted for by fat?
25-35%
L1: What enzyme activates hormone-sensitive lipase?
Protein Kinase A
L1: What is a required coenzyme for acetyl CoA carboxylase?
Biotin
L1: What is the rate limiting enzyme in cholesterol synthesis?
HMG CoA reductase
L1: What type of fat? Fish and seafood
Omega-3 fat
L1: What type of fat? Margarine, processed foods
Trans fats
L1: Which lipid? Important in signal transduction, reservoir for arachidonic acid
Phosphatidylinositol
L1: Which lipid? Most abundant phospholipid in the body, important in lung surfactant, present in bile
Phosphatidylcholine
L1: Which lipoprotein? 10:1 triglyceride:cholesterol ratio, very large
Chylomicrons
L1: Which lipoprotein? Reservoir of phospholipids
HDL
L1: Which lipoprotein? Very atherogenic, more cholesterol than triglycerides
LDL
L1: Which tissue contains glycerol kinase, which can convert glycerol directly to glycerol-phosphate?
Liver
L2: _____ catalyzes exchange of cholesterol esters and triglycerides between VLDL and HDL.
Cholesterol Ester Binding Protein (CETP)
L2: _____ is produced in the rate limiting step of ketone body synthesis.
HMG CoA
L2: ______ are the ketones produced in ketogenesis.
3-hydroxybutyrate, Acetone
L2: ______ catalyzes transfer of a fatty acid to cholesterol to trap it in HDL.
Lecithin Cholesterol Acyltransferase (LCAT)
L2: ______ is produced in the rate-limiting step of cholesterol synthesis.
Mevalonate
L2: Beta oxidation in the mitochondira involves __ steps and produces _______.
4; NADH, FADH2, acetyl-CoA
L2: Fatty acid addition to glycerol is catalyzed by _______.
Acyltransferase
L2: Fatty acids are desaturated by ________ in the ER.
Mixed Function Oxidases
L2: How does insulin increase the action of acetyl CoA carboxylase?
Activation of phosphoprotein phosphatase to dephosphorylate acetyl CoA carboxylase to its active form
L2: In negative energy states, triglycerides are broken down by ________.
Hormone-sensitive lipase
L2: Malonyl CoA is converted to _______ by ______ in fatty acid synthesis.
Palmitic acid; fatty acid synthase
L2: Name two fatty acids that must be obtained from the diet.
Linoleic acid, linolenic acid
L2: Polymerization of Acetyl CoA carboxylase ______ its function.
increases
L2: The initial substrate for ketogenesis is _______.
Acetyl CoA
L2: What enzyme is rate-limiting in fatty acid synthesis?
Acetyl CoA Carboxylase
L2: What facilitates transport of cholesterol from tissues to HDL
ABC-A1 binding cassette
L2: What is a key inhibitor of CPT1?
Malonyl CoA
L2: What is produced in the rate-limiting step in fatty acid synthesis?
Malonyl CoA
L2: What is the ligand for the LDL receptor?
apoprotein B100
L2: What is the ligand for the remnant particle receptor?
apoprotein E
L2: What is the rate limiting enzyme in beta oxidation?
Carnitine Palmitoyl Transferase 1 (CPT1)
L2: What is the rate limiting enzyme in ketogenesis?
HMG CoA synthase
L2: What type of fat? Manteca, red meat fat, lard
Saturated
L2: What type of fat? Olive oil and canola oil
Monounsaturated fat
L2: What type of fat? Vegetable and corn oils
Omega-6 fat
L2: When a fatty acid has an odd number of carbons, the final three carbon molecule, ______, is converted to _______.
Proprionyl CoA, succinyl CoA
L2: Which apoproteins are present on newly synthesized chylomicrons? Which are acquired in circulation?
B48; C2, E
L2: Which apoproteins are present on newly synthesized HDL? Which are acquired in circulation?
A1, C2, E; none
L2: Which apoproteins are present on newly VLDL/LDL? Which are acquired in circulation?
B100; C2, E
L2: Which fatty acid synthesis intermediate activates Acetyl CoA carboxylase?
Citrate
L2: Which fatty acid synthesis intermediate inhbits Acetyl CoA carboxylase?
Malonyl CoA
L2: Which glycolysis intermediate can be converted to glycerol for fatty acid synthesis? What tissues does this occur in?
Dihydroxyacetone-Phosphate; Liver and adipose tissue
L2: Which lipoprotein? Atherogenic, 1:1 triglyceride:cholesterol ratio
Remnant Particles
L3: What additional enzymes may be required for breakdown of unsaturated fatty acids?
3,2-enoyl CoA isomerase, NADPH-dependent reductase
