BRAINCAKECellular Respiration
Revision notes for Cellular Respiration in Edexcel Biology (9BI0). Read the start of any lesson here, then sign in free for the whole lesson, the R.E.C.I.P.E. recall steps and the quiz.
- Cellular RespirationCellular respiration is the set of enzyme-controlled reactions in which energy is released from a respiratory substrate, such as glucose, and used…
- ATPATP (adenosine triphosphate) is the immediate source of energy for reactions in cells.
- Aerobic RespirationAerobic respiration is respiration that uses oxygen.
- Respiration in the CytoplasmThe first stage of respiration, glycolysis, happens in the cytoplasm of the cell, outside the mitochondria.
- MitochondriaMitochondria are the organelles where the link reaction, the Krebs cycle and oxidative phosphorylation take place.
- Hydrogen AcceptorsMany steps in respiration are oxidation reactions in which hydrogen atoms are removed from a substrate.
- Investigating the Rate of RespirationThe rate of aerobic respiration can be measured with a respirometer, which measures the rate of oxygen uptake by small organisms such as woodlice…
- Investigating the Site of ATP SynthesisHow do we know which parts of the cell carry out each stage of respiration?
- GlycolysisGlycolysis (sugar splitting) is the first stage of both aerobic and anaerobic respiration.
- Anaerobic Respiration in MammalsWhen oxygen is in short supply, as in muscles during vigorous exercise, the electron transport chain stops because there is no final electron…
- LactateLactate produced during anaerobic respiration does not stay in the muscle.
- Sprint AthletesA 100 m sprinter needs a huge amount of ATP very quickly, far faster than oxygen can be delivered to the muscles.
- Anaerobic Respiration in Plants and FungiPlants and fungi such as yeast can also respire without oxygen, for example yeast in a sealed fermenter or plant roots in waterlogged soil.
- Discovery of GlycolysisFor much of the 19th century, scientists argued about how fermentation happens.
- Aerobic Respiration: SummaryHaving studied each stage, we can now follow a glucose molecule all the way through aerobic respiration.
- The Link ReactionWhen oxygen is available, the pyruvate from glycolysis is actively transported into the mitochondrial matrix, where the link reaction takes place.
- The Krebs CycleThe Krebs cycle takes place in the mitochondrial matrix.
- The Electron Transport ChainThe electron transport chain is the final stage of aerobic respiration.
- ChemiosmosisChemiosmosis is the process that uses the proton gradient built up by the electron transport chain to make ATP.
- Net Gain of ATPAdding up the products of each stage shows how much ATP aerobic respiration can make from one glucose molecule.