|
Creado por mollie.dawson
hace más de 9 años
|
|
Pregunta | Respuesta |
What are enzymes? (3) | Globular proteins Have a specific tertiary structure Catalyse metabolic reactions in living organisms |
What is a catalyst? | A substance which speeds up a chemical process without being used up in the reaction itself |
Is enzyme action intracellular or extracellular? | Both |
What type of protein is an enzyme? | Globular |
What determines the active site? | Tertiary structure |
What lowers the activation energy? | Formation of enzyme-substrate complex |
How can activation energy be lowered? (2) | When two molecules are joined via enzyme Breakdown reaction via enzyme |
How is activation energy lowered when two molecules are joined? | They attach to enzyme which holds them together - reducing repulsion effect |
How is activation energy lowered in a breakdown reaction? | Fitting into the active site puts a strain on bonds, so molecule breaks easier |
How does the induced fit model differ from the lock and key model? | Induced fit model incorporates that the enzyme-substrate complex changes shape slightly to fit |
What affects rate of reaction? (4) | Temperature pH Enzyme concentration Substrate concentration |
How does temperature affect rate of reaction? (4) | Higher temperature makes enzyme molecules vibrate more If temp goes above certain temperature, vibrations break some bonds which hold enzyme together Active site changes shape Enzyme is denatured |
How does pH affect the rate of reaction? | Enzymes have an optimum pH Above & below optimum, H+ and OH- ions in acids and alkali's mess up ionic & hydrogen bonds that hold tertiary structure |
What does catalase catalyse? | Breakdown of hydrogen peroxide into water and oxygen |
What does Amylase catalyse? | Breakdown of starch to maltose, iodine detects starch |
What does an inorganic cofactor do? | Help the enzyme and substrate to bind together |
So are inorganic cofactors changed or used up in any way? | No |
What are manganese ions? | Cofactors found in hydrolase |
What are organic cofactors called? | Coenzymes |
What do coenzymes do? | They act as carriers, moving chemical groups between different enzymes |
Are coenzymes altered during reactions? | Yes, they're continually recycled |
So what is a coenzyme? | An organic cofactor which participate in the reaction and changed by it, they move chemical groups between enzymes and are continually recycled during this process |
Can enzyme activity be inhibited? | Yes |
What is competitive inhibition? | Competitive inhibitor molecules have a similar shape to substrate, they compete with substrate molecules to bind to active site, block active site so no reaction |
What is non-competitive inhibition? | Non-competitive molecules bind to enzyme away from its active site, causing active site to change shape, so substrate molecules can't bind to it |
What type of bond creates an irreversible inhibitor? | Strong, covalent bond |
What type of bond creates a reversible inhibitor? | Weak, hydrogen/ionic |
What is a metabolic poison? | An enzyme inhibitor |
What is cyanide an irreversible inhibitor of? | Cytochrome c oxidase, which catalyses respiration reactions |
What does penicillin do? | Inhibits transpeptidase, which catalyses the formation of proteins in bacterial cell walls, weakening cell wall, Boom, bacterium has burst |
¿Quieres crear tus propias Fichas gratiscon GoConqr? Más información.