Transcript respiration2

Glycolysis and Krebs cycle The biochemistry of aerobic respiration only in
sufficient detail to
show that:
• glycolysis involves the oxidation of glucose to pyruvate with a net
gain of ATP and reduced NAD;
• pyruvate combines with coenzyme A to produce acetylcoenzyme
A;
• acetylcoenzyme A is effectively a two-carbon molecule which
combines with a four-carbon molecule to produce a six-carbon
molecule which enters Krebs cycle;
• Krebs cycle involves a series of oxidation reactions and the release
of carbon dioxide leading to the production of ATP and reduced
coenzyme (NAD or FAD);
• synthesis of ATP is associated with the electron transport chain.
Mitochondria The structure and role of mitochondria in respiration.
Aerobic Respiration
Define the following:
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•
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Respiration
Breathing
Aerobic respiration
Anaerobic respiration
Aerobic Respiration
Respiration is the process that releases energy in organic
molecules such as sugars and lipids. Respiration takes place in
all cells all of the time
Breathing is the mechanical process that supplies oxygen to the
body for respiration and that removes carbon dioxide produced.
Breathing ventilates the gas exchange surfaces.
Aerobic Respiration is respiration with oxygen – most
organisms respire aerobically releasing a relatively large
amount of energy.
Anaerobic respiration is respiration without oxygen – some
organisms mainly bacteria can only respire anaerobically
others can switch to anaerobic when oxygen levels are low.
Aerobic Respiration
Aerobic respiration describes the cell processes that
require oxygen to release energy from all organic
molecules.
Respiration involves the breakdown of many molecules
from the food we eat.
Humans respire mainly sugars but also some amino acids
and fatty acids.
Aerobic Respiration
• For any chemical reaction to occur energy
is required to break bonds.
• The process of forming new bond can
either release energy of require eenergy
• For there to be a release of energy the
products of respiration must be at a lower
energy level than the reactants.
Aerobic Respiration
• What is the basic equation for respiration?
• C6H12O6 + 6O2 6CO2 + 6H20 + ENERGY
• In reality cell respiration takes place in a
series of stages , these can produce a up to
36 molecules of ATP per molecule of glucose
• The steps involved in respiration rely on a
series of redox reactions
Aerobic Respiration
Energy in
molecules
Combustion
has one step
and occurs very
rapidly
Glucose and oxygen
CO2 +H2O
Time
Glucose and oxygen
Energy in
molecules
CO2 +H2O
Time
Energy is lost
as heat
Respiration
occurs in small
steps and
releases energy
in controlled
amounts. Less
energy is lost as
heat
Aerobic Respiration
NH 2
N
N
OOO
O - P - O - P - O - P - O - CH2
OO
O
N
O
adenosine
AMP
ADP
ATP
N
Aerobic Respiration
ATP + H2O
AMP + H2O
ADP + H2O
30.5 kJ mol
Pi
-1
30.5 kJ mol
Pi
-1
adenosine
14.2 kJ mol
Pi
-1
Aerobic Respiration
The process of aerobic respiration can be
divided into 4 distinct processes:
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Glycolysis
Pyruvate Oxidation
The Krebs cycle
The electron transport chain
Aerobic Respiration
Stage
Site Within Cell
Overall process
Number of
ATP
molecules
produced
Glycolysis
Cytosol
Glucose is split into 2
molecules of pyruvate
2 per
glucose
molecule
Pyruvate
Oxidation
Matrix – inner
fluid of
mitochondria
Pyruvate is converted to
acetyl co A
none
Krebs Cycle
Electron
Transport
Chain
Aceytyl co A drives a cycle 2 per turn
of reactions to produce
so 4 per
hydrogen
glucose
Inner memebrane Hydrogen drives a series
of mitochondria
of redox reactions to
produce ATP
Up to 32 per
glucose