enzymes Flashcards
(22 cards)
What are enzymes?
Proteins that allow chemical reactions to take place at normal body temperature.
What would happen without enzymes?
Reactions would be too slow to be of any use to the body.
What is the role of enzymes in chemical reactions?
They are biological catalysts specific to one particular reaction.
True or False: Enzymes are consumed in a chemical reaction.
False
What is the Lock and Key model in relation to enzymes?
Each enzyme is specific to only one reaction, and its shape defines the active site.
What is the active site of an enzyme?
The place where the substrate(s) can bind.
What is activation energy?
The energy required to get started in a chemical reaction.
How do enzymes affect activation energy?
They reduce the activation energy needed to begin a reaction.
What factors affect enzyme activity? (List at least three)
- Enzyme concentration
- Substrate concentration
- Temperature
What happens to the rate of reaction with increased enzyme concentration?
The rate of chemical reaction increases.
How does substrate concentration affect enzyme activity?
Increasing substrate concentration increases the rate of reaction until saturation occurs.
What is saturation in the context of enzyme activity?
When all enzyme molecules are fully occupied, increasing substrate concentration will cease to have an effect.
What effect does removing products of a reaction have on enzyme activity?
It prevents the slowing of the reaction rate.
How does temperature influence enzyme activity?
Rate of most chemical reactions increases as temperature increases, within a limited range.
What happens to enzymes at temperatures above 45-50°C?
They become denatured (permanently inactivated).
What is the optimal temperature range for most human enzymes?
Between 30°C and 40°C.
How does pH affect enzyme activity?
Each enzyme has an optimal pH at which it works most effectively.
What are co-factors?
Certain ions or non-protein molecules required for enzyme catalysis.
What is the role of co-enzymes?
Non-protein organic molecules, many of which function as vitamins.
What are enzyme inhibitors?
Substrates that slow or stop the enzyme’s activity.
Give an example of an enzyme inhibitor.
Penicillin inhibits an enzyme in bacteria involved in cell wall construction.
List the factors affecting enzyme activity.
- Enzyme concentration
- Substrate concentration
- Removing products of reaction
- Temperature
- pH
- Co-factors & co-enzymes
- Enzyme inhibitors
