Enzymes + Models Flashcards
What are enzymes?
Globular proteins and biological catalyst that speed up rate by lowering activation energy
Why are enzymes important?
Most reactions need to take place fast without the addition of high temp and pressure which cells cannot handle
Give example of anabolic (building up) reactions that are catalysed by enzymes?
-synthesis of Large polymer-based components, e.g: cellulose forming cell walls, long protein molecules forming contractile filaments of muscles in animals
Give an example of catabolic (breaking down) reactions catalysed by enzymes-
Glucose being broken down to produce energy used for many processes in the body including growth.
How are large organic molecules like glucose obtained?
Digestion of food, which is made of even larger molecules like starch. This process if also catalysed by enzymes
How is enzymes involved in metabolism?
Metabolism is the sum of all metabolic reactions in a cell or organism which can only happen as a result of the control and order imposed by enzymes
What is the lock and key hypothesis?
The active site (lock) doesn’t change shape and is only complementary to one substrate (key)
What happens when the substrate locks to the active site?
An enzyme-substrate complex is formed, the substrate then reacts and produces are fomed, producing a enzyme-product complex, the products are then released
How are bonds involved in enzymes catalysing reactions?
The substrate are held in a way that the R-groups within the active site will also react with the substrate, which create temporary bonds which put strain of the bonds in the substrate.
What’s the induced fit hypothesis?
Suggests the active site changes shape slight as substrate enters. The initial reaction is weak, which rapidly induces change in the enzymes tertiary structure that strengthens binding and puts strain on the substrate molecule. This weakens bonds in the substrate.
What are intracellular enzymes?
Enzymes that act within the cell
Give an example of a intracellular enzyme and its function-
Catalyse- protect cells from damage by breaking down hydrogen peroxide
What are extracellular enzymes?
Enzymes that are secreted and act outside the cell
Give an example of an extracellular enzyme and its function-
Amylase- secreted by by cells lining digestive system that act in gut cavity.
