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WorksheetsQuiz on Enzymes
Total questions: 20
Worksheet time: 10mins
What are enzymes?
Lipids
Carbohydrates
Biological catalysts
Nucleic acids
Which of the following is true about enzymes?
They are consumed in reactions
They accelerate chemical reactions
They are simple sugars
They have no specific substrates
What is the substrate?
The product of the reaction
The enzyme
The reactant that the enzyme acts on
A cofactor
What does the active site of an enzyme do?
Catalyzes the reaction
Binds the substrate
Inhibits other enzymes
Changes shape permanently
In the Lock and Key model, how do the enzyme and substrate interact?
The enzyme changes shape
They fit together perfectly
The substrate binds randomly
The substrate alters the enzyme's function
Which model describes the enzyme adapting to fit the substrate?
Lock and Key Model
Induced Fit Model
Competitive Inhibition Model
Noncompetitive Inhibition Model
Cofactors are:
Always proteins
Nonprotein molecules assisting enzyme function
Only found in bacteria
The same as substrates
Which of the following is NOT a type of cofactor?
Metal ions
Coenzymes
Amino acids
Prosthetic groups
What is an example of an irreversible inhibitor?
Competitive inhibitors
Heavy metals
Coenzymes
Allosteric activators
Competitive inhibitors:
Bind permanently to the enzyme
Resemble the substrate and compete for the active site
Bind to the allosteric site
Enhance enzyme activity
What does allosteric regulation involve?
Binding at the active site
Binding at the allosteric site
Permanent enzyme modification
Change in substrate concentration
Feedback regulation primarily affects which type of enzyme?
All enzymes equally
Rate-limiting enzymes
Noncompetitive inhibitors
Cofactors
What is the term for the enzyme combined with its cofactor?
Apoenzyme
Holoenzyme
Isoenzyme
Substrate complex
Enzyme activity is typically expressed as:
Grams of product
Micromoles of substrate converted per minute
Volume of reaction
Temperature of the enzyme
Which of the following can be a positive allosteric effector?
A substrate
A product
A molecule that enhances enzyme activity
An irreversible inhibitor
What role do isoenzymes play?
Catalyze different reactions
Catalyze the same reaction but differ in structure
Always enhance enzyme activity
Act as substrates
An example of a coenzyme derived from a vitamin is:
Glucose
NAD
Hemoglobin
RNA
The term "apoenzyme" refers to:
Enzyme with its cofactor
The protein portion of a holoenzyme
The substrate of the enzyme
An inactive enzyme
Covalent modification of enzymes usually involves:
Temperature changes
Addition/removal of phosphate groups
Changes in pH
Inhibition by metal ions
Elevated levels of ALT and AST in plasma typically indicate:
Muscle damage
Liver damage
Kidney function
Normal enzyme activity
