enzymes Flashcards
(15 cards)
What is activation energy?
The minimum amount of energy needed to start a chemical reaction.
How do enzymes catalyse reactions?
They lower the activation energy, allowing reactions to take place at lower temperatures than normal, facilitating rapid metabolic processes.
What type of proteins are enzymes?
Globular.
What is an active site?
The specific region of the enzyme that is functional, made up of a small amount of amino acids, forming a small depression in the enzyme.
What is the induced fit model of enzyme action?
A scientific model proposing that the active site forms as the enzyme and substrate interact, with the enzyme being flexible and able to mold around the substrate.
How to measure rate of change using a graph?
Gradient.
Effect of temperature on enzyme action?
A rise in temperature increases kinetic energy of molecules, leading to more effective collisions and more enzyme-substrate complexes formed.
How can temperature denature enzymes?
If the temperature is too high, hydrogen bonds and other bonds in the enzyme molecule start to break, changing the shape of the enzyme and its active site.
How is pH calculated?
pH = -log[H+].
How does pH affect enzyme action?
Changes in pH alter the charges on amino acids in the active site, affecting substrate attachment and enzyme activity.
Effect of enzyme concentration on activity?
An increase in enzyme concentration leads to an increase in rate unless substrate is limiting.
Effect of substrate concentration on enzyme activity?
Rate of reaction increases with substrate concentration until it levels off when there is an excess of substrate.
What are competitive enzyme inhibitors?
Molecules that mimic the shape of the substrate and compete for available active sites.
What are non-competitive inhibitors?
Molecules that attach to an enzyme at a binding site that is not the active site, altering the enzyme’s shape and function.
