B2.3 Enzymes Flashcards
Enzymes act as ______
Catalysts
How do enzymes work?
An enzyme has an active site and using the lock and key mechanism, it fits into the substrate
Substrate splits into products which leave the active site and the enzyme is ready to use again
The active site is a specific shape
An enzyme doesn’t die, it ________
Denatures
What do enzymes do in the liver?
It breaks down poisonous hydrogen peroxide into non poisonous water and hydrogen
H2O2 —-catalase—-> 2H2O + H2
Define catalyst
A substance which changes the rate of a chemical reaction without being change itself
Define enzyme
A biological catalyst made from proteins
Define enzyme-substrate complex
The enzyme and substrate bound together
Define activation energy
The energy needed for a chemical reaction to take place
Define active site
The special site in the structure of an enzyme where the substrate binds
Why would a human die if their body temperature reached 50 degrees c?
The enzymes would denature and not be able to break down anything in their body therefore their respiratory system would stop and enzymes allow you to sweat so thermoregulation in your body would stop too. Not enough energy would reach your brain meaning you’d die.
What factors affect rate of reaction in enzymes? (6)
Temperature pH Enzymes concentration Substrate concentration Surface area Pressure
What’s the optimum temperature of enzymes?
The temperature where enzymes work best at - different enzymes have different optimums
What are the graphs for rate of reaction with a) temperature, b) pH, c) pepsin?
Look them up 👊🏽
What is pepsin?
An enzyme in gastric juice that digests protein. It’s in the membrane lining the stomach. It can deal with pH 1.5 acidity
What’s lipase?
And enzyme that breaks down dietary fats into smaller molecules called fatty acids and glycerol
It’s mainly in your pancreas but also in your stomach
