, Energy flow through living organisms
decomposers
sun photosynthesis producers consumers
Respiration
Heat (low energy radiation transferred back to
the atmosphere)
, Energy release & respiration
In photosynthesis energy provided from the sun allows organic
molecules to be made from small inorganic molecules.
Respiration is a complex multistep reaction pathway. In respiration
large organic molecules are broken down forming small inorganic
molecules. Organic molecules contain large numbers of carbon-hydrogen
bonds, particularly lipids. These bonds are non polar & the total energy
required to break them is less than the total energy released in the
formation of all the bonds in the products (CO² & water). The excess
energy released by the formation of all the bonds is used to synthesise
ATP.
Reasons for loss of efficiency in ATP production during aerobic
respiration:
Energy losses transporting materials (e.g. pyruvate) across the
mitochondrial membrane
Loss of protons (H+) through the inner mitochondrial membrane
without driving ATP synthesis
Some energy is used to transport protons & electrons from reduced
NAD in the cytoplasm into the mitochondrial matrix
(malate/aspartate shuttle)
, Glycolysis
• Glycolysis is an example of substrate level phosphorylation- the formation of ATP
without the involvement of an electron transport chain. ATP is formed by the transfer
of a phosphate group from a phosphorylated intermediate to ADP.
• Glycolysis occurs in the cytoplasm of the cell
• It is an anaerobic process
1.Phosphorylation- 2 phosphates released from 2
ATP molecules, are attached to a glucose molecule
forming hexose bisphosphate
2.Lysis- Destabilises the molecule causing it to split
into 2 triose phosphate molecules
3.Phosphorylation- Another phosphate group is
added to each triose phosphate forming 2 triose
bisphosphate molecules. These phosphate groups
come from free inorganic phosphate (Pi) ions
present in the cytoplasm
4.Dehydrogenation & formation of ATP-
The 2 triose bisphosphate molecules are
oxidised by the removal of hydrogen atoms
(dehydrogenation) to form 2 pyruvate
molecules. NAD coenzymes accept the
removed hydrogens forming 2 reduced
NAD molecules.4 ATP molecules are also
produced using phosphates from the triose
bisphosphate molecules.
decomposers
sun photosynthesis producers consumers
Respiration
Heat (low energy radiation transferred back to
the atmosphere)
, Energy release & respiration
In photosynthesis energy provided from the sun allows organic
molecules to be made from small inorganic molecules.
Respiration is a complex multistep reaction pathway. In respiration
large organic molecules are broken down forming small inorganic
molecules. Organic molecules contain large numbers of carbon-hydrogen
bonds, particularly lipids. These bonds are non polar & the total energy
required to break them is less than the total energy released in the
formation of all the bonds in the products (CO² & water). The excess
energy released by the formation of all the bonds is used to synthesise
ATP.
Reasons for loss of efficiency in ATP production during aerobic
respiration:
Energy losses transporting materials (e.g. pyruvate) across the
mitochondrial membrane
Loss of protons (H+) through the inner mitochondrial membrane
without driving ATP synthesis
Some energy is used to transport protons & electrons from reduced
NAD in the cytoplasm into the mitochondrial matrix
(malate/aspartate shuttle)
, Glycolysis
• Glycolysis is an example of substrate level phosphorylation- the formation of ATP
without the involvement of an electron transport chain. ATP is formed by the transfer
of a phosphate group from a phosphorylated intermediate to ADP.
• Glycolysis occurs in the cytoplasm of the cell
• It is an anaerobic process
1.Phosphorylation- 2 phosphates released from 2
ATP molecules, are attached to a glucose molecule
forming hexose bisphosphate
2.Lysis- Destabilises the molecule causing it to split
into 2 triose phosphate molecules
3.Phosphorylation- Another phosphate group is
added to each triose phosphate forming 2 triose
bisphosphate molecules. These phosphate groups
come from free inorganic phosphate (Pi) ions
present in the cytoplasm
4.Dehydrogenation & formation of ATP-
The 2 triose bisphosphate molecules are
oxidised by the removal of hydrogen atoms
(dehydrogenation) to form 2 pyruvate
molecules. NAD coenzymes accept the
removed hydrogens forming 2 reduced
NAD molecules.4 ATP molecules are also
produced using phosphates from the triose
bisphosphate molecules.
