Karteikarten
Enzymes
Karten in diesem Stapel (30)
- 1What are enzymes? (3)Globular proteins
Have a specific tertiary structure
Catalyse metabolic reactions in living organisms - 2What is a catalyst?A substance which speeds up a chemical process without being used up in the reaction itself
- 3Is enzyme action intracellular or extracellular?Both
- 4What type of protein is an enzyme?Globular
- 5What determines the active site?Tertiary structure
- 6What lowers the activation energy?Formation of enzyme-substrate complex
- 7How can activation energy be lowered? (2)When two molecules are joined via enzyme
Breakdown reaction via enzyme - 8How is activation energy lowered when two molecules are joined?They attach to enzyme which holds them together - reducing repulsion effect
- 9How is activation energy lowered in a breakdown reaction?Fitting into the active site puts a strain on bonds, so molecule breaks easier
- 10How 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
- 11What affects rate of reaction? (4)Temperature
pH
Enzyme concentration
Substrate concentration - 12How 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 - 13How 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 - 14What does catalase catalyse?Breakdown of hydrogen peroxide into water and oxygen
- 15What does Amylase catalyse?Breakdown of starch to maltose, iodine detects starch
- 16What does an inorganic cofactor do?Help the enzyme and substrate to bind together
- 17So are inorganic cofactors changed or used up in any way?No
- 18What are manganese ions?Cofactors found in hydrolase
- 19What are organic cofactors called?Coenzymes
- 20What do coenzymes do?They act as carriers, moving chemical groups between different enzymes
- 21Are coenzymes altered during reactions?Yes, they're continually recycled
- 22So 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
- 23Can enzyme activity be inhibited?Yes
- 24What 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 - 25What 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
- 26What type of bond creates an irreversible inhibitor?Strong, covalent bond
- 27What type of bond creates a reversible inhibitor?Weak, hydrogen/ionic
- 28What is a metabolic poison?An enzyme inhibitor
- 29What is cyanide an irreversible inhibitor of?Cytochrome c oxidase, which catalyses respiration reactions
- 30What does penicillin do?Inhibits transpeptidase, which catalyses the formation of proteins in bacterial cell walls, weakening cell wall,
Boom, bacterium has burst
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- Karteikarten am Enzymes, erstellt von mollie.dawson am 24/03/2015.
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