Term | Definition |
Catabolic | A reaction which releases energy and breaks down molecules. |
Electron transport chain | The final stage of respiration where high energy electrons and hydrogen ions are used to synthesise ATP. |
ATP | The energy-carrying molecule used in cells because it can release energy very quickly. |
Feedback inhibition | The first enzyme of a metabolic pathway is inhibited by the reversible binding of the final product of the pathway. |
Fermentation | A type of respiration which takes place in the absence of oxygen. |
Pyruvate | A molecule formed during glycolysis which, when oxygen is present, enters the matrix of the mitochondrion to start the citric acid cycle. |
NAD | A co-enzyme which easily attaches to hydrogen ions, but releases them when they are required. |
Anabolic | A reaction which requires energy and builds up molecules. |
Non-competitive inhibition | A molecule binds to part of the enzyme away from the active site, and causes a change in shape of the active site of the enzyme, thereby inhibiting the binding of the appropriate substrate molecule. |
ADP | A low energy molecule that forms ATP when a phosphate molecule is added. |
Phosphorylation | The addition of a phosphate group. |
ATP synthase | An enzyme which produces ATP. |
Dehydrogenase | An enzyme which removes hydrogen ions and electrons from substrates |
Oxaloacetate | Combines with acetyl coenzyme A to form citrate during the citric acid cycle. |
Competitive inhibition | Occurs when an inhibitor, resembling the structure of the substrate, binds to the active site of the enzyme and blocks the
binding of the substrate |
FAD | An alternative to NAD. A co-enzyme which easily attaches to hydrogen ions, but releases them when they are required. |
Metabolism | The chemical processes that occur within a living organism in order to maintain life. |
Induced fit | A slight change in shape (a squeeze) of the active site of the enzyme that allows the substrate to fit perfectly |
Citrate | Formed during the citric acid cycle when oxaloacetate combines with acetyl coenzyme. |
Energy investment phase | The first phase of glycolysis where 2 molecules of ATP are required. |
Glycolysis | The first stage of respiration where glucose is broken down into pyruvate. |
Lactate | Pyruvate is converted to this molecule during fermentation/anaerobic respiration. |
Matrix of mitrochondrion | The specific area of a mitochondrion where the citric acid cycle takes place. |
Energy pay-off phase | The last phase of glycolysis where 4 molecules of ATP are produced. |
Anaerobic respiration | Respiration that takes place without oxygen. Also known as fermentation. |