3. Tissue/Organ and Overview of Metabolism Flashcards
metabolism
chemical reactions and processes occurring in the body
2 categories of metabolism
catabolism + anabolism
catabolism
breaks down large molecules into smaller units
anabolism
synthesizes large molecules from small units by using energies produced in catabolism
most important organ for metabolism in body
liver
where does the liver provide fuel
brain, muscle + other peripheral organs
functions of liver
- help digest, absorb and process food
- detoxifies chemicals and metabolizes drugs
- stores glucose in form of glycogen
what does the liver synthesize?
bile acids
glucose
ketone bodies
VLDL
cholesterol
triacylglycerols
phosphoglycerides
how does the liver utilize glycogen
break down glycogen to release glucose -> blood glucose is used as energy fuels by many different tissues => controls blood glucose level
function of muscle
major biochemical transducer that converts chemical energy into mechanical energy
muscle - major fuels
glucose, fatty acids + ketone bodies
major glycogen storage in body?
muscle
what is glycogen converted to in muscle?
glucose-6-phosphate for use within the muscle cells
fuel for brain?
glucose
when are ketone bodies used in the brain?
during prolonged starvation, ketone bodies partly replace glucose as fuel for the brain
how does adipose tissue store energy?
in the form of lipids
what does adipose tissue produce?
hormones (leptin + estrogen) and cytokines
what fuel do RBCs use?
glucose as energy fuel
function of blood
- deliver oxygen to tissues and remove carbon dioxide from the body
- transport nutrients
where are ketone bodies synthesized?
liver
why are ketone bodies not used in the liver?
livers lack the enzyme thiotransferase
what are ketone bodies used for?
ATP production by brain, muscle and kidney
Thromboxane A2 (TXA2): where is it produced and what does it do
produced by platelets and stimulates platelet aggregation
Prostacyclin (PGI2): where is it synthesized and what does it do
synthesized by endothelial cells of the artery and it inhibits platelet aggregation
where are bile acids synthesized and stored?
synthesized in the liver and stored in the gall bladder
where are bile acids secreted?
small intestine
why are bile acids important?
bile acids are required to digest dietary fats in the intestine
why are muscles unable to convert pyruvate back to glucose
they have extremely low conc. of glucose-6-phosphate
where is glucose-6-phosphate abundant?
liver
