EN: Photosynthesis, Respiration and ATP Flashcards
Give examples of things plants need energy for:
- Photosynthesis
- Active transport
- DNA replication
- Cell division
- Protein synthesis
Give examples of things animals need energy for:
- Muscle contraction
- Maintenance of body temperature
- Active transport
- DNA replication
- Cell division
- Protein synthesis
What is the overall equation for photosynthesis?
6CO2 + 6H2O + Energy —> C6H12O6 + 6O2
Describe photosynthesis in words:
The process where energy from light is used to make glucose from H2O and CO2 (light energy is converted to chemical energy in the form of glucose).
Where is energy stored in plants?
In the glucose, until it is released by respiration.
How do animals obtain glucose?
How do they release energy?
By eating plants/other animals.
Release energy by respiration.
Why is respiration useful?
The energy released is used to power all the biological processes in a cell.
What are the two types of respiration?
What is the difference?
Aerobic respiration - using oxygen.
Anaerobic respiration - without oxygen.
What does aerobic respiration produce?
What is the equation?
Carbon dioxide + water + releases energy.
C6H12O6 + 6O2 —> 6CO2 + 6H2O + energy.
What does anaerobic respiration produce in plants and yeast?
Glucose —> ethanol and carbon dioxide
What does anaerobic respiration produce in humans?
Glucose —> lactate + energy
What is ATP?
Adenosine triphosphate.
The immediate source of energy in a cell.
Why is ATP needed?
A cell can’t get its energy directly from glucose.
So ATP is needed to carry the energy around the cell to where it’s needed.
The energy released from glucose is used to make what?
ATP
Briefly describe how ATP is synthesised?
A condensation reaction between ADP and inorganic phosphate, using the energy from an energy-releasing reaction.
Where is the energy stored in ATP?
As chemical energy in the phosphate bond.
What catalyses the reaction of ATP synthesis?
The enzyme ATP synthase.
Draw ATP:
What does ATP diffuse to?
What happens next?
The part of the cell that needs energy.
It’s hydrolysed back into ADP and inorganic phosphate. Chemical energy is released from the phosphate bond and used by the cell.
What catalyses the breakdown of ATP?
ATP hydrolase.
What happens to the products of the hydrolysis of ATP?
ADP and inorganic phosphate are recycled and the process starts again.
Why is ATP and good energy source?
- Energy released is small and manageable - so no energy wasted as heat.
- Small, soluble molecule so can be easily transported around the cell.
- Easily broken down so energy can be released instantaneously.
- Quickly re-made.
- Makes other molecules more reactive by phosphorylation.
- Can’t pass out of the cell, so cell always has an immediate supply of energy.
Phosphorylation.
The action of one molecule transferring a phosphate group to another molecule.
The action of one molecule transferring a phosphate group to another molecule.
Phosphorylation.
Metabolic pathway
A series of amll reactions controlled by enzymes.
Photophosphorylation
Adding phosphate to a molecule using light.
Photolysis
The splitting of a molecule using light energy.
Photoionisation
When light energy ‘excites’ electrons in an atom or molecule, giving them more energy and causing them to be released.
Hydrolysis
The splitting of a molecule using water.
Decarboxylation
The removal of carbon dioxide from a molecule.
Dehydrogenation
The removal of hydrogen from a molecule.
Redox reactions.
Reactions that involve oxidation and reduction.
A series of amll reactions controlled by enzymes.
Metabolic pathway
Adding phosphate to a molecule using light.
Photophosphorylation
The splitting of a molecule using light energy.
Photolysis
When light energy ‘excites’ electrons in an atom or molecule, giving them more energy and causing them to be released.
Photoionisation
The splitting of a molecule using water.
Hydrolysis
The removal of carbon dioxide from a molecule.
Decarboxylation
The removal of hydrogen from a molecule.
Dehydrogenation
Reactions that involve oxidation and reduction.
Redox reactions.
The release of electrons during photoionisation causes what?
The atom or molecule to become a positively-charged ion.
Describe reduction:
- The gain of electrons/hydrogen
- The loss of oxygen
Describe oxidation:
- The loss of electrons/hydrogen
- The gain of oxygen
Oxidation of one molecule always …
… involves the reduction of another molecule.
Coenzyme
A molecule that aids the function of an enzyme.
A molecule that aids the function of an enzyme.
Coenzyme
Briefly describe how coenzymes work:
By transferring a chemical group from one molecule to another.
What is the coenzyme in photosynthesis?
How does it work?
NADP.
Transfers hydrogen from one molecule to another - so it can reduce or oxidise a molecule.
Give examples of coenzymes in respiration.
NAD, coenzyme A and FAD.
What do the coenzymes used in respiration do?
NAD and FAD - transfer hydrogen from one molecule to another - this means they can reduce or oxidise a moleucle.
Coenzyme A - transfers acetate between molecules.
