2.4

cellular respiration

rebuilds ATP from ADP

cellular respiration equation

glucose + oxygen → carbon dioxide + water

32 ADP + 32P → 32 ATP

photosynthesis _____ energy; respiration _____ releases

requires; releases

steps of cell respiration

Glycolysis, citric acid cycle, electron transport chain and ATP synthase

glycolysis

• glucose is broken down into smaller sugars

• a small amount of ATP is produced

• some electrons are transferred to NADH

Citric Acid Cycle

• small organic compounds broken down into CO2

• a small amount of ATP produced

• many electrons are transferred to NADH

Electron Transport Chain and ATP synthase

• electrons from NADH are transferred to O2 to make H2O

• a lot of ATP is produced in a similar manner to light reactions of photosynthesis

Cell respiration makes 32

ATP molecules from 1 glucose molecule

glycolysis takes place in the

cytoplasm, with no CO2 produced and no O2 needed

sub-level phosphorylation

phosphate transferred directly from substrate to ADP

phosphofructokinase

• catalyzes first step that irreversibly commits substrate to glycolysis

• allosterically (don’t bind to active site but affects active site) regulated

  • negative feedback by ATP, citrate

  • simulated by AMP (from ADP)

why do we want ATP + citrate to inhibit glycolysis

to maintain steady use of glucose, to not use it all so fast

why is glucose activated by AMP (produced by ADP)

ATP → ADP + phosphate means low levels of ATP, so makes glucose

citric acid cycle takes place in

the mitochondria (the matrix)

the matrix is

within the inner membrane

electron transport chain + ATP synthase found in

the inner membrane

ETC is the movement of

electrons from carriers (high energy state) through ETC to oxygen to make water (low energy state) powers active transport of hydrogen ions into space between membranes, generating a gradient

because of the ETC a high concentration of H+ ions are found in

the space between membranes

ATP synthase is

a spinning turbine that uses hydrogen ion flow to drive atp production

oxygen is the ETCs final electron acceptor

this is why we need oxygen