respiration
Post on 02-Jan-2016
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RespirationThe process in which organisms breakdown glucose.
The energy in the chemical bonds of glucose is eventually captured in ATP molecules for use by
an organism to do work
C6H12O6 + 6 O2 6CO2 + 6 H2O + ATP energy
Occurs in 3 major steps
glycolysis
Krebs cycle
Electron transport system (ETS)
Redox RxKey to transferring energy from one
molecule to another
Glucose ATP
As e- ‘fall’ from molecule to molecule (oxidation/reduction), energy is captured to form
ATP from ADP and phosphate group
Organisms use ATP as energy source to do work
glycolysis
Occurs in cytoplasm
10 step process
Prokaryotes and eukaryotes
anaerobic
Net 2 ATP (by substrate level phosphorylation)
2 NADH (nicotinamide adenine dinucleotide)
2 pyruvate (3C)
Glycolysis stepsglucose
(hexokinase) and ATP ADP
Glucose 6-phosphate
(phosphoglucoisomerase)
Fructose 6-phosphate
*(phosphofructokinase) and ATP ADP
Fructose 1,6-biphosphate
(aldolase) *Allosteric enzyme inhibited By ATP and citrate
Glycolysis stepsX 2 Glyceraldehyde phosphate
(triose phosphate dehydrigenase)+ 2 NADH + 2 H+
1,3-diphosphoglycerate (phosphoglycerokinase)
+ ATP
3-phosphoglycerate (phosphoglyceromutase)
2-phosphoglycerate
(endolase) + 2 H2O
Glycolysis stepsX 2 phosphoenolpyruvate
( pyruvate kinase)+ ATP
pyruvate
Final products of glycolysis = 2 pyruvate2 NADH2 ATP (net)
Pyruvate Krebs cycle if aerobicfermentation if anaerobic
NADH + H+ ETS
ATP do ‘work’
fermentationIn anaerobic conditions, pyruvate molecules are broken down in a process called fermentation
Alcohol fermentation (yeast, fungi, bacteria)
Products = ethanolCO2
NAD+ (recycled)
Krebs cycleIn aerobic conditions, pyruvate enters the Krebs cycle(runs X2 for each glucose)
In mitochondria
Eukaryotes only
Hans Krebs
Products = 2 ATP (by substrate level phosphorylation)NADHFADH2
Krebs cycle Pyruvate converted to acetyl CoA
Requires coenzyme AGives off CO2 and NADH
Acetyl CoA combines with oxaloacetic acid
Forms citric acid
Citric acid isocitrate -ketoglutaric acid Succinyl CoA succinate fumarate Malate Oxaloacetic acid (to start cycle over)
Krebs cycle stepsKrebs cycle products
Oxaloacetic acid regenerated to run cycle
2 ATP to do ‘work’
6 NADH + 6 H+ ETS
2 FADH2 ETS
6 CO2
ETSEnergy in e- from NADH and FADH2 travel‘down’ series of electron carriers in redox RxEnergy used to pump H+ from matrix to intermitochondrial space
H+ diffuse through ATP synthase to make ATP (chemiosmosis)Back into matrix
H+ + e- combine with O2 to form water
O2 final e- acceptor
Electron Transport Chain: The Movie
ETSO2 used to combine with 2H+ and 2e- to form H2O
NAD+ regenerated for Krebs cycle
FAD+ regenerated for Krebs cycle
32-34 ATP generated via chemiosmosis
Total ATP = 2 + 2 + 34 = 38
Cellular Respiration
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