Metabolism and hormones Flashcards
describe glycolysis. where does it occur? does it require o2?
glycolysis - break down of 6 carbon sugar into two 3 carbon sugars
- occurs in cytoplasm w/o need for o2
- regulatory enzymes made by free ribosomes
requires 2 P from ATP to get started
end with 2 NADH, 2 pyruvic acids, 2 ATP
what is the intermediate step of the citric acid cycle?
pyruvic acid get transformed into acetyl coa
- 1st formation of CO2
releases NADH
describe the citric acid cycle. what is produced in the end? does it occur?
occurs in matrix of mitochondria
oxaloacetic acid (6C) + acetyl CoA (2 C) = citric acid
- 2 CO2 released
- H lost to NAD and FAD
- energy + GDP = GTP
by the end of citric acid cycle, all carbons from glucose have been released as CO2
- source of CO2 in blood and expiration
where does electron transport occur and how does that increase efficiency?
occurs along plasma membrane of cristi of the mitochondria
- increases efficiency bc only one component is moving
why do we need redox reaction for the hydrogens on NAD? how does affinity affect energy?
need redox bc E in hydrogens are too high - too much heat would be released
- controlled rxns allow decrease of energy
- extra energy used to move H ions from inner matrix to outer
increasing chemical affinity means that there is less E to hold onto the electron
- at end of chemical affinity chain, e- recombined with H and moved back into matrix
how does ATP synthase work?
the H gradient made by the electron transport chain allows H to move down its gradient into the intracellular matrix thru the ATP synthase
- rotor that spins - energy causes ADP + P = ATP
creates 34 app
describe glycogenesis and glycogenolysis
glycogenesis - glucose made into glycogen
- anabolic
glycogenolysis - glycogen to glucose
- catabolism
- only certain cells (liver) can do this
describe gluconeogenesis. where does this not occur? what is beta oxidation?
body uses energy storage other than glucose
beta oxidation - FA catabolism
- long chain FA broken into 2 C groups - acetyl CoA
- occurs especially in heart
- enters where GP3 would be
does not occur in the brain, tease, erythrocyte, kidney medulla
describe where fats and amino acids can enter the carbohydrate catabolism pathway
fats
- glycerol can enter during glycolysis
- fatty acids - B oxidation for acetyl CoA
aa’s - can enter at pyruvic acid or acetyl CoA step
describe the absorptive state
blood levels of AA, lipids, and glucose are elevated
increased glucose causes increase in insulin
describe the post absorptive state
AA, glucose and lipids moved into cells for usage or storage
- decreased levels i the blood
hormone - glucagon
- maintain homeostatic glucose in the blood.
describe malnutrition and malnourishment
malnutrition - ingestion of too few/many calories
malnourishment - improper balance of carbs, proteins or lipids
- enough calories but not enough vitamins or minerals
describe growth hormone. what is its effects on blood AA, FA, glucose> what is it produced by?
produced by andenohypophesis (anterior pituitary)
- regulated by hypothalamus
- decrease in blood AA - increased protein synthesis
- increase in blood FA - used for energy instead of glucose
- increase in blood glucose: can cause DM2 due to increased insulin
describe the thyroid system. what is it related by?
adenohypophesis releases thyroid stimulating hormone
- regulated by hypothalamus
thyroglobulin - inactive form
- stood in center portion
- lysosomes break down inactive parts of thyroglobulin
T3/T4 + iodide move into plasma membrane
what is the function of T3/4 and iodide? how does it affect blood levels of FA and glucose?
important for metabolism and brain development/activity
- functions similar to steroid hormones
- modulates gene expression
increases blood levels of FA
lowers blood levels of glucose - taken out of blood
