CELLULAR RESPIRATION
CELLULAR RESPIRATION
AEROBICWith Air (oxygen) in the presence of oxygen
not 100% efficient: ATP produced (40%), energy is lost in heat (60%)
- used to keep body temp up- kept there by insulation (fat, skin, fur/hair
etc)36 ATP produced (38 in liver, heart and kidneys)
more efficient energy transfer
ANAEROBIC
Without Air (Oxygen) not in the presence of oxygen
Occurs in cytosol
2 ATP produced (far less efficient)
production of lactic acid
less efficient energy transfer
FASTER!
Lactate can be broken down by repaying the bodies oxygen debt
GLYCOLISIS = glucose break down into 2 pyruvates (3C) occurs inside a cytoplasm specific enzymes catalyse each step vitamins act as coenzymes for many reactions
Glucose=> 2x pyruvate (see diagram) 6C 3C energy is released, some is used to make net 2ATP
hydrogen ions (H+) are removed (from the glucose molecule), they and their electrons are collected by acceptor molecules (e.g. NAD)
makes a loaded acceptor (2 NADH)
2 ATPs
KREBS CYCLE (CITRIC ACID CYCLE)
=Pyruvate to carbon dioxide Occurs in Mitochondrial matrix Pyruvate leaves cytosol & enters mitochondria
1 (3C) Pyruvate --> 3CO2
(--> Acetyl Coenzyme A) 2C
Acceptor molecules collect Hydrogen atoms 4 x NADH (nicotinamide adenine dinucleotide) 1 x FADH2 (flavine adenine dinucleotide)
2 ATPs
ELECTRON TRANSPORT CHAIN & PHOSPHORYLATION
Accounts for almost 90% of ATP generated
Occurs in the inner membrane of the mitochondrion (membrane of cristae)
e- are transferred from one cytochrome to another, finally excepted by oxygen to form H2O
e- transport releases energy (2 e- ->2-3 ATPs)
Phosphorylation =adding a phosphate ADP +P -> ATP
34 ATPs
AEROBIC RESPIRATION OVERALL
One molecule of glucose ---> 36 molecules of ATP
The heart, liver and kidney ---> 38 molecules of ATP
Glycolysis is the only stage that can occur without oxygen - thus 2ATP are produced in anaerobic respiration.
The Kreb's cycle will not occur unless oxygen is present
Oxygen is needed as part of the ETC
ANAEROBIC RESPIRATION (HUMAN)
glucose -> 2 pyruvate -> lactic acid2 ATPs
ANAEROBIC RESPIRATION (FERMENTATION)
glucose -> 2 pyruvate ->2 ethanol
CO2
2 ATPs