Metabolic Pathways (1.6) Flashcards
What is cell metabolism (1)
The collective term for all the chemical reactions that take place in a living cell.
What is meant by Anabolic reactions (1)
Anabolic reactions BUILD UP large molecules from small molecules and REQUIRE ATP. E.g. ATP required to build up amino acids to form a protein.
What is meant by Catabolic reactions (1)
Catabolic reactions BREAK DOWN large molecules into smaller molecules and RELEASE ATP.
What are examples of degradation reactions in the human body (1)
HPCOW: Hydrogen peroxide + catalyse = oxygen + water.
What are metabolic pathways (1)
A metabolic pathway is a series of stepwise chemical reactions that are controlled by enzymes.
What are the two types of metabolic pathways (2)
Anabolic and Catabolic.
In a metabolic pathway, what controls each step (1)
Enzymes.
What are enzymes (1)
Enzymes are biological catalysts.
What is a catalyst (1)
A Catalyst is a substance that speeds up the rate of reaction by lowering the ATP needed to make the reaction proceeds.
Why do enzymes speed up (1)
Biological reactions causes this.
What is the energy needed to break the chemical bonds in a chemical reaction called (1)
Activation energy.
What is induced fit (1)
Induced fit is when the active site can change shape slightly when it comes in contact with a substrate molecule for a better fit.
What does affinity mean (1)
An attraction for something.
If a substrate has a high affinity for the active site, what does the active site do (1)
The active site holds the reactants together together in an induced fit. This acts to weaken the chemical bonds in the reactants. This allows the reaction to take place.
Once the reaction has taken place what do the products have and what does this cause to happen(1)
The products have a low affinity for the active site and are therefore released.
What is an inhibitor (1)
Is a substance that reduces the rate if an enzyme reaction.
What are the two types of enzyme inhibitor (2)
Competitive and non-competitive.
What does a competitive inhibitor do / What does a non-competitive inhibitor do (2)
inhibitors compete for the active site with the substrate; Inhibitors don’t compete for the active site
How does feedback inhibition do and how does this work?
Feedback Inhibition occurs when the end product in the metabolic in the metabolic pathway reaches a critical concentration. The end product inhibits an earlier enzyme, blocking the pathway, and so prevents further synthesis of the end product. This regulates the whole pathway.
Give an account of enzyme action (5)
Substrate has a high affinity for the active site; induced fit; enzymes lower the activation energy; products have a low affinity for the active site; substrate and product concentration effect the direction of reactions
Give an account of the effects of competitive & non-competitive inhibition (4)
Competitive inhibition- The inhibitor resembles the substrate molecule; inhibition is reduced by increase in substrate concentration.
Non-Competitive inhibition-The shape of the active site changed; the inhibitor binds at a site other than the active site.
