Lecture 31 Unit 4 Flashcards
how can lipids be transported in blood
if they combine with a protein
describe lipoproteins
spheres containing hundreds of molecules
how are lipoproteins categorized
by function and density
what are the 4 major classes of lipoproteins
- chylomicrons
- very low density
- low density
- high density
what makes up chylomicrons
2% protein, 85% TG
where to chylomicrons form
in intestinal epithelial cells to transport dietary fats to adipose cells
what makes up very low density lipoproteins
10% protein 50% TG
where do VLDLs form
in hepatocytes to transport triglycerides to adipose cells
what makes up low density lipoproteins
25% protein 50% cholesterol (bad cholesterol)
what do LDLs do
carry blood cholesterol to body cells
what makes up high density lipoproteins
40% protein 20% cholesterol (good cholesterol)
what do HDLs do
carry cholesterol from cells to liver for elimination
what is the “fate of lipids”
oxidized to produce ATP
where are excess lipids stored
in adipose tissue or liver
what do lipids synthesize
- phospholipids for plasma membranes
- lipoproteins that transport cholesterol
- thromboplastin for blood clotting
- myelin sheaths to speed up nerve conduction
- cholesterol used to synthesize bile salta nod steroid hormones
what is thromboplastin made of
phospholipids and tissue factor
what happens in lipolysis
triglycerides are broken down into glycerol and fatty acids within liver or adipose cells in the presence of epinephrine, norepinephrine, or cortisol
what happens in lipogenesis
triglycerides are synthesized from amino acids or glucose within liver or adipose cells in the presence of insulin
what do fatty acids in lipolysis undergo in mitochondria and what do they produce?
they undergo beta oxidation to produce acetyl CoA and lots of ATP
where does ketogenesis occur
in liver cells
what are ketone bodies use by and for?
used by heart muscle and kidney cortex for ATP production
what are the fuel sources for lipogenesis
- amino acids, glycolysis metabolites, and ketone bodies for fatty acid production from Acetyl CoA
- glycolysis metabolites for glycerol production
what is the “fate of proteins”
they are broke down into amino acids which are transported to the liver
what could happen to amino acids
- deaminated to enter Krebs cycle
- donate amino group to form new amino acid-transamination
- used to synthesize new proteins throughout the body
