BLD 402 LIPIDS EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED GRADED A++
What is the structure of cholesterol?
Lipid with a steroid backbone
What are the four biological functions of cholesterol?
Component of cell membranes
precursor to bile acids
precursor to steroid hormones
precursor to vitamin D
How much of the body's cholesterol comes from diet?
Only half
What is cholesterol synthesized from and in what organ?
acetyl-CoA in the liver
What two ways is cholesterol removed from the body?
Fecal cholesterol from bile
Skin/hair shedding
Why is cholesterol esterified?
To be less polar
Prevent intracellular toxicity by free cholesterol: Too much free CHOL would migrate
into the cell membrane which would not allow the cell to function properly
What is the esterification enzyme in cells?
, Acyl-CoA-cholesterol acyltransferase (ACAT)
What is the esterification enzyme in plasma?
Lecithin-cholesterol acyltransferase (LCAT)
T/F: Cholesterol is esterified and hydrolyzed back in forth in the body
T
What is the structure of fatty acids?
Carboxylic acid with long carbon chain
What are essential fatty acids?
fatty acids that the body needs but cannot make and so must be obtained from the diet
How many carbons does a fatty acid lose per round of the B-oxidation cycle?
Two
Where do the 2 carbons go?
TCA cycle to make ATP
When do ketone bodies form?
Excess Acetyl-CoA in the liver
What is the structure of a triglyceride?
glycerol + 3 fatty acids
What are the 3 functions of a triglyceride?
Fat storage
Carbon sources
Energy sources
What is the structure of a phospholipid
glycerol, two fatty acids, and a phosphate group
COMPLETE SOLUTIONS VERIFIED GRADED A++
What is the structure of cholesterol?
Lipid with a steroid backbone
What are the four biological functions of cholesterol?
Component of cell membranes
precursor to bile acids
precursor to steroid hormones
precursor to vitamin D
How much of the body's cholesterol comes from diet?
Only half
What is cholesterol synthesized from and in what organ?
acetyl-CoA in the liver
What two ways is cholesterol removed from the body?
Fecal cholesterol from bile
Skin/hair shedding
Why is cholesterol esterified?
To be less polar
Prevent intracellular toxicity by free cholesterol: Too much free CHOL would migrate
into the cell membrane which would not allow the cell to function properly
What is the esterification enzyme in cells?
, Acyl-CoA-cholesterol acyltransferase (ACAT)
What is the esterification enzyme in plasma?
Lecithin-cholesterol acyltransferase (LCAT)
T/F: Cholesterol is esterified and hydrolyzed back in forth in the body
T
What is the structure of fatty acids?
Carboxylic acid with long carbon chain
What are essential fatty acids?
fatty acids that the body needs but cannot make and so must be obtained from the diet
How many carbons does a fatty acid lose per round of the B-oxidation cycle?
Two
Where do the 2 carbons go?
TCA cycle to make ATP
When do ketone bodies form?
Excess Acetyl-CoA in the liver
What is the structure of a triglyceride?
glycerol + 3 fatty acids
What are the 3 functions of a triglyceride?
Fat storage
Carbon sources
Energy sources
What is the structure of a phospholipid
glycerol, two fatty acids, and a phosphate group
