05.0 Enzymes - AI testing Flashcards
What are enzymes?
Biological catalysts made of proteins
What is a catalyst?
Substance that increases the rate of a chemical reaction without being changed itself
What do enzymes control?
Specific reactions that make life possible
How do enzymes work?
They lower the activation energy required for a reaction to occur
What are substrates?
The beginning molecule in the reaction that binds to the enzyme at the active site
What is the active site of an enzyme?
Highly specific region where substrates bind
What is an enzyme-substrate complex?
The formed complex when substrates bind to the enzyme
What happens to products after a reaction?
They can be released, allowing the enzyme to perform another reaction
How many reactions can enzymes perform per second?
Hundreds, with some enzymes like catalase performing tens of millions
What factors affect enzyme activity?
Amount of substrate, temperature, pH, presence of coenzymes or cofactors, inhibitors, heavy metals, availability of energy
What is saturation in enzyme kinetics?
When all active sites of the enzyme are occupied due to increased substrate
What is the relationship between enzymes and cofactors?
Most enzymes require cofactors to work, which can be inorganic ions or non-protein organic molecules
What are prosthetic groups?
Non-protein organic molecules that are permanently bound to enzymes, e.g. heme in catalase
What are coenzymes?
Organic molecules that react with the substrate and can be released by the enzyme, e.g. ATP, NAD
What is enzyme specificity?
Enzymes usually catalyze only a particular reaction
What is an example of enzyme specificity?
Invertase catalyzes the hydrolysis of sucrose to glucose and fructose
What is irreversible inhibition?
When a covalent bond is formed between the inhibitor and the enzyme, not easily broken
What is reversible inhibition?
When the inhibitor molecule binds through attractive forces, affecting enzyme function
What is a competitive inhibitor?
Blocks the substrate from entering the active site
What is a non-competitive inhibitor?
Does not bind to the active site but affects enzyme function by binding elsewhere
How does temperature affect enzyme activity?
Increase in temperature increases molecular movement, leading to more frequent collisions with active sites
What happens if temperature exceeds the optimum for an enzyme?
The enzyme will begin to denature
What is the difference between partially denatured and completely denatured enzymes?
Partially denatured enzymes can regain their shape after cooling; completely denatured cannot function correctly again
