S&F; Harvesting Energy Flashcards
how is energy produced?
hydrolysis of atp to adp + inorganic phosphate
what is the atp cycle?
simple molecules (glucose/amino acids/glycerol/fatty acids) -> anabolic reactions from ATP to complex molecules -> complex molecules (glycogen, proteins, triglycerides) -> catabolic reactions = complex molecules -> ATP
what type of fuel is needed for atp?
carbohydrates (simple sugars)
proteins (amino acids)
fats (simple fats)
what are the two fates for glucose?
into cellular respiration (cellular work)
or into storage for harder times (glycogen)
what are the steps to cellular respiration
- glycolysis
- pyruvate oxidation
- krebs cycle
- electron transport chain.
where does cellular respiration occur?
- cytosol
- matrix
- matrix
- across inner membrane
glycolysis
produces 2atpnet + 2nadh
lysis occurs, producing 2 pyruvate molecules
pyruvate oxidation
intermediate step
produces no atp
2nadh (1 per pyruvate)
2co2 (1 per pyruvate)
which steps require oxygen?
everything except glycolysis
citric acid cycle/krebs cycle
2atp
6nadh
2fadh2
4co2
features of the citric acid cycle
product of the reaction = substrate for the next.
each step can be part of another process
types of phosphorylation
substrate phosphorylation and oxidative phosphorylation
substrate phosphorylation
atp generated by direct transfer of a phosphate group to adp
glycolysis + citric. acid cycle
oxidative phosphorylation
atp generated by oxidation of nadh + fadh2, subsequent transfer of electrons + pumping of protons
electron transport chain
- nadh + fadh2 are oxidized to donate electrons
- electrons transfer from protein-protein along chain in a series of redox reactions
3.each electron gives up a small amount of energy at each transfer, enabling h+ ions to be pumped into inter membrane space
- oxygen pulls electrons down the chain, and is reduced to water.
chemiosis
hydrogein ions rush down concentration gradiant (atp synthase) —> turbine within atp synthase to turn
rotation of atp synthase turbine = phosphorylation of adp to generate atp (26/28 atp)
what is rate limiting for glycolysis?
phosphofructokinase, bc its inhibited by citrate + atp (will work slower)
stimulated by amp (accumulates when atp is being used rapidly)
what is insulin?
produced by beta cels of islets of langerhans in pancreas
promotes glucose uptake into cells (for atp production/storage in liver)
what is glucagon
produced by alpha cells in islets of langerhans in pancreas
stimulates the breakdown of glycogen to increase blood sugar levels
what is diabetes
the ability to produce/respond to the hormone insulin is impaired
results in abnormal metabolism of carbohydrates + elevated levels of glucose in the blood
type 1 diabetes
body does not produce insulin, beta cells are destroyed.
often through genetic/environmental factors
usually in children, affects 5-10%.
requires insulin replacement
type 2 diabetes
body produces insulin, but receptors are non-functional
most diabetics + adults over 40
linked to other pathologies + obesity
