Enzymes Flashcards
(17 cards)
What are enzymes?
Biological catalysts that speed up chemical reactions without being used up or changed themselves
Enzymes function in living systems and are specific to substrates.
What is an active site?
The specific region on an enzyme where substrates bind
The active site is critical for the enzyme’s function.
What is enzyme-substrate specificity?
The complementary shape and chemical properties of an enzyme’s active site and its substrate
This ensures that only specific substrates can bind to the enzyme.
What determines the specificity of an enzyme?
The complex 3-D shape of the protein that makes up the enzyme
The order of amino acids in the protein chain affects this shape.
What happens during an enzyme-catalyzed reaction?
Substrates collide with the active site, forming an enzyme-substrate complex
The reaction occurs within this complex, leading to product formation.
What are catabolic reactions?
Reactions that break down complex molecules into simpler products
Examples include cellular respiration and hydrolysis reactions.
What are anabolic reactions?
Reactions that build complex molecules from simpler ones
Examples include protein synthesis and photosynthesis.
What factors affect enzyme activity?
Temperature, pH, and substrate concentration
Each factor influences the rate of enzyme-catalyzed reactions.
What is the optimum temperature for enzymes?
The temperature at which an enzyme catalyzes a reaction at the maximum rate
Higher temperatures can lead to denaturation.
How does temperature affect enzyme activity?
Lower temperatures slow down reactions, while higher temperatures increase reaction rates until denaturation occurs
Denaturation causes a sharp drop in enzyme activity.
What is pH?
A measure of hydrogen ion concentration in a solution
pH affects enzyme structure and function.
What effect do extremes of pH have on enzymes?
They can cause irreversible denaturation of the enzyme
Each enzyme has an optimum pH for activity.
How does substrate concentration affect enzyme activity?
Increases in substrate concentration initially increase reaction rates until active sites are saturated
Beyond saturation, additional substrate does not increase the rate of reaction.
What is denaturation in enzymes?
The process where bonds holding the enzyme’s 3D shape break, causing loss of function
Denatured enzymes can no longer bind substrates.
At what temperature do most human enzymes denature?
Above 50°C
Human body temperature is around 37°C.
True or False: Enzymes can be used up in chemical reactions.
False
Enzymes are not consumed in the reactions they catalyze.
Fill in the blank: The temporary formation of an _______ occurs when a substrate binds to an enzyme.
enzyme-substrate complex
This complex is crucial for the reaction to take place.
