cellular respiration Flashcards
(26 cards)
exergonic
release energy
catabolic
products have less energy than reactants
(cell respiration)
ex:
- digesting food
- hydrolysis of ATP to ADP
endergonic
requires energy
anabolic
products have more energy
examples: active transport, cell movements, building proteins, synthesis of ATP from ADP
ATP
adenosine TRIphosphate
3 phosphate groups - a lot of energy
ATP is made when cell has EXTRA energy
ADP
adenosine DIphosphate
two phosphate groups - some energy
ADP is made by removing phosphate group
(cell uses energy in ATP)
ATP -> ADP
lost energy
endergonic
oxidation
oxidized: molecules LOSES electrons
“oil”
breaking of a chemical bond -> makes a positive ion
NAD+
glucose is oxidized -> energy released
reduction
reduced: molecule GAINS electrons
builds a new chemical bond with the electron
makes a negative charged ion
“rig”
NADH
oxygen is reduced (given energy poor electrons)
cell res formula
C6H12O6 + 6O2 —> 6CO2 + 6H2O
4 steps of cellular respiration
glycolysis -> pyruvate oxidation -> krebs -> oxidative phosphorylation
glycolysis
glucose -> pyruvate
*cytoplasm
substrate level phosphorylation
generates 2 forms of energy: ATP & NADH
glucose: 6 carbons, each pyruvate has 3 carbons
glycolysis formula
glucose + 2 ATP + 2 NAD+ —> 2 pyruvate + 2 net ATP + 2 NADH
(4 ATP made - 2 ATP gain)
pyruvate oxidation
pyruvate -> acetyl coenzyme A
mitochondrial MATRIX (middle-center fluid filled)
pyruvate oxidation formula
2 pyruvate + 2 NAD + 2 coenzyme A —>
2 acetyl coenzyme A + 2 CO2 + 2NADH
citric acid krebs cycle
mitochondrial matrix
- removes energy rich electrons from processed pyruvates
- harvests remaining energy in acetyl coenzyme A
4 ATP made
1 glucose makes 2 acetyl coA: process happens twice
2 carbons leave as CO2 —> generates NADH
4 remaining carbons -> ATP & electron carriers
citric acid formula
2 acetyl coA + 6NAD+ +2FAD (+oxaloacetate) ->
oxaloacetate + 4 CO2 +2ATP + 6NADH +2FADH2
oxidative phosphorylation
builds most of ATP
1. ETC creates h+ gradient across inner mitochondrial membrane
2. chemiosmosis: ATP synthase uses gradient to build ATP
ETC
- electrons travel through ETC protein complexes
- its energy used by proteins to pump H+ ions into inter membrane space
- electrons no longer store energy -> combine with O2
chemiosmosis
ATP synthase: ATP generating protein in inner mitochondrial membrane - allows protons to move back into matrix
proton motive force: energy released when protons move back in
^ uses the force to create ATP
(movement of 4 protons make 1 molecule of ATP)
role of O2
only required in oxidative phosphorylation
final electron acceptor at end of ETC
- removes low energy electrons, making room for new electrons
fermentation
no oxygen
to regenerate NAD+
(by oxidizing NADH)
alcohol fermentation
used by yeast to regenerate NAD+
pyruvate -> ethanol
NADH provides required electrons oxidizing it back into NAD+
- generates lots of CO2
lactic acid ferm
regenerate NAD+ in
bacteria, fungi, mammals
pyruvate -> lactic acid
feedback inhibition
a LOT of atp: inactive enzymes
LITTLE atp: active enzymes
pH/lactic acid buildup can also affect enzyme activity
electron carriers
- ETC uses energy from electron carriers to create H+ concentration gradient
- capture energy from chemical reaction & transport it
- uber for electrons
primary electron carriers: NAD+/NADH
FAD/FADH2
