Session 2: Enzymes Flashcards
What is the metabolic process of anabolism?
the formation of macromolecules (complex molecules) from monomers by condensation reactions.
What is the metabolic process of catabolism?
the breakdown/hydrolysis of macromolecules (complex) into monomers (simple molecules).
What is metabolism? Do anabolic reactions or catabolic reactions produce energy?
Chemical reaction in bodies cells, turn food into energy, metabolism requires enzymes. Anabolic reactions require energy in order to occur, catabolic reactions produce energy.
What are metabolic pathways?
Metabolic pathways are where enzymes work together, each enzyme is a step in a series of steps, in order for a metabolic reaction to occur. They are a series of linked biochemical reactions where enzymes activate each step of the pathway. Pathways are controlled by regulating the amount of enzyme present. (Product for one step becomes substrate for the next, etc.)
What is the lock & key theory of catalysing enzymes?
Substrate is the key, active site is the lock. There is one specific enzyme for one specific substrate.
What is the Induced Fit model/theory of catalysing enzymes?
Also known as broad specificity, Induced fit is where some enzymes will undergo conformational change after the substrate goes into the active site. The active site will physically change to fit the substrate more snugly. This theory means that enzymes can bind to multiple kinds of substrates.
How do enzymes speed up the rate of reaction?
Enzymes lower the amount of activation energy (Ea) (amount of energy required for a reaction to occur) because when an enzyme binds to a substrate it stresses and destabilises bonds in the substrate, increasing reactivity. With enzymes, reactions can occur faster and more efficiently.
What is a cofactor? And what are the three types of cofactors?
Some enzymes require non-protein cofactors to complete catalytic properties and functions. The three types of cofactors are inorganic ions, coenzymes, and prosthetic groups.
What are the four factors which impact enzymes?
Enzymes have their own individual sets of conditions in which they work best. The factors are enzyme concentration, substrate concentration, temperature, and acidity and alkalinity (pH).
What is enzyme inhibition?
Inactivation of an enzyme. Can be reversible or irreversible, competitive or non-competitive. It can occur at high temperatures or by changes in pH (non-specific factors that would inactivate any enzyme). Enzyme activity can also be regulated by specific factors, such as poisons because they bind to particular enzymes and inactivate them.
What is the difference between competitive and non-competitive inhibition?
Competitive inhibition is where the inhibitor tries to reach the active site before the substrate can (will have similar structure to substrate so it can fit). Competitive inhibition is generally reversible, it will leave the active site and the substrate goes in and the reaction continues as normal. Non-competitive inhibition is when the inhibitor binds to site other than the active site (allosteric site) and causes conformational change to the active site so that the substrate cannot fit. Non-competitive inhibition is generally irreversible (will stay permanently attached)
What is enzyme denaturation?
when chemical bonds are broken due to (changes) in temperature and pH outside the enzymes optimum range. Denatured enzymes are no longer active and cannot function.
What is an enzyme (revision)?
An enzyme is a biological catalyst that speeds up biological reactions and regulates cell metabolism. They bind to substrates at the active site.
What is an inorganic ion (cofactors)?
Examples include iron, magnesium, and zinc (ions have charge). Ions may help to stabilise structure of enzyme or may take part in the reaction at the active site.
What is an organic molecule/coenzyme (cofactors)?
These types of cofactors link different enzyme/catalysed reactions into a sequence during metabolic processes. They often accept or donate hydrogen ions or chemical groups. Vitamins are important in the production of coenzymes.
