Cellular Respiration

Question 1

Cellular respiration

Answer 1

Release energy from food
Glucose + 6O2 -> 6CO2 + 6H2O + 38 ATP (in practice more 30 or below)
heat as by product
Glycolysis 2ATP -> Kreb’s cycle 2ATP -> Electron transport chain ~30ATP

Energy comes from the breakdown of ATP with hydrolysis into ADP + energy

Question 2

Glycolysis

Answer 2

Glucose + 2ATP -> 2 pyruvate + 4ATP + 2NADH
net production: 2ATP and 2NADH
this is an anaerobic process
takes place in cytoplasm

Question 3

Anaerobic respiration

Answer 3

only glycolysis can take place
Krebs and electron transport chain are aerobic processes
pyruvate builds up -> fermentation with lactate dehydrogenase -> lactic acid and NAD+ -> taken up by liver -> convert back to pyruvate and glucose -> bloodstream -> glycolysis can take place -> prevents lactic acidosis
This is part of the Cori cycle

Question 4

Citric Acid Cycle

Answer 4

Krebs cycle
Takes place in mitochondria matrix
net production 2 ATP
aerobic process: oxygen required to do the oxidations
carbon is deoxynated through the cycle
preparation: glucose -> glycolysis -> pyruvate -> oxidation +CO2 -> NAD+ into NADH -> NADH and pyruvate -> acetylcoa
AcetylCoa with oxaloactic acid -> citric acid -> oxidation steps
Through steps:
NAD+ into NADH
ADP into ATP (GDP/GTP)
FAD into FADH2 (Q/QH2)
Cycle loops back to AcetylCoa with oxaloactic acid -> citric acid

TCA spins twice: 1 glucose (2ATP 2NADH) -> 2 pyruvate (oxidation: 2 NADH) -> 2 ATP + 6 NADH + 2 FADH2 from TCA

Question 5

Oxidative phosphorilation

Answer 5

Electron Transport Chain (ETC) then Chemiosmosis
ETC pump electrons and create the proton gradient
Chemiosmosis the generation of ATP using the gradient

Question 6

Electron Transport Chain

Answer 6

Series of redox
Energy source: NADH & FADH2
From mitochondrial matrix to intermembrane space of the matrix it pumps H+ ions to create a proton gradient

Closely interact with TCA
O2 needed for final step for ETC !

NADH -> complex I -> become NAD+ -> complex I is supercharged -> pump H+ -> stop supercharge and pass electrons to CoQ
FADH2 -> complex II -> becomes FAD gives e- -> complex II gives e- to CoQ
CoQ gives all e- to complex III -> complex III supercharged -> pumps H+
Complex III gives e- to cytochrome c -> gives to complex IV -> complex IV supercharged -> pumps H+
complex IV gives e- to O2 -> transformed into 2H2O

Question 7

Cyanide

Answer 7

prevent cellular respiration
cytochrome c oxidase is inhibited, unable to produce ATP: complex IV cannot go on
binds unreversably to heme so oxygen can’t bind

Question 8

Beta oxidation

Answer 8

Break down of fatty acids in cytosol and mitochondria
Generates: ActetylCoA(used for Krebs Cycle), NADH and FADH2 ( coenzymes of electron transport chain)
Beta oxidation depends on the length of the fatty acid
oxidation to carbony group
facilitated by mitochondrial trifunctional protein: innermembrane mitochondria and matrix

Question 9

Chemiosomosis

Answer 9

Follows the electron transport chain
Proton gradient: H+ intermembrane space&raquo_space;»> H+ matrix
H+ wants to travel down the proton gradient: high to low for equilibrium
H+ travel through ATP synthase from intermembrane space to the matrix -> energy input to catalyze ADP to ATP

Question 10

Complex names ETC

Answer 10

Complex I: NADH ubiquinone oxireductase
Complex II: succinate dehydrogenase
Complex III: cytochrome bc complex
Complex IV: cytochome c oxydase