Respiration Flashcards
why do organisms need to respire
produces ATP needed for
-active transport against concentration gradient
-metabolic reactions
-muscle contraction
releases heat energy for thermoregulation
describe structure of mitochondria
surrounded by double membrane
folded inner forms cristae-site of ETC fluid matrix contains mitochondrial DNA, digestive enzymes, lipids and proteins
name 4 main stages of aerobic respiration and where they occur
glycolosis=cytoplasm
link reaction=mitochondria matrix
krebs cycle=matrix
oxidative phosphorylation=membrane of cristae
outline stages of glycolosis
glucose phosphorylated to hexose bisphosphate using 2 ATP
hexose busphosphate splits into 2 triose phosphate
2 TP oxidised to 2 pyruvate
net gain of 2 ATP and 2 red NAD
how does pyruvate from glycolosis enter mitochondria
active transport
what happens during link reaction
oxidation of pyruvate to acetate
net gain of CO2 and 2 hydrogen atoms
acetate combines with coenzyme A to produce acetylcoenzyme A
what happens in the kreb cycle
acetyl group binds with oxaloacetate to form citrate
cycle recyles oxaloacetate
produces ATP by substrate level phosphorylation
-reduced coenzymes
-CO2 from decarboxylation
what is the electron transport chain
series of carrier proteins embedded in membrane
produces ATP through oxidative phosphorylation
what happens in ETC
electrons released from reduction of NAD and FAD undergo successive redox reactions
energy released is coupled to maintaining proton gradient
oxygen acts as final electron acceptor
how does chemiosmosis produce ATP
some energy released from ETC is coupled to active transport of H+ ions from matrix to intermembrane space
H+ ions move down concentration gradient into matrix via ATP synthase ATP synthase catalyses ADP-ATP
what stages in respiration produce ATP through substrate level phosphorylation
aerobic=kreb cycle
anaerobic=glycolysis
what happens during anaerobic respiration
only glycolosis continues so much less ATP produced
pyruvate decarboxylated to form ethanal
ethanal reduced to ethanol using red NAD to produce NAD for further glycolysis
what are the benefits of being able to respire anaerobically
ATP production still continues
production of ethanol/lactate converts red NAD back to NAD so that glycolysis can continue
how could you compare effect of variables on respiration
use respirometer
a dye as terminal electron acceptor for ETC
what is the purpose of sodium hydroxide in a respirometer
absorbs CO2 so there is a net decrease in pressure as O2 consumed
