Practise MYP Biology questions on 3.3 Enzymes and review the explanations to check your understanding.
Use these questions for topic practice and to find ideas you want to revisit in your notes or lessons.
When an enzyme provides an "alternative reaction pathway" for a biochemical reaction, how does this mechanism specifically contribute to a faster reaction rate?
An enzyme is defined as a catalyst because it speeds up a reaction and emerges from the process __________.
Without the presence of enzymes, the vast majority of biochemical reactions inside a cell would occur at a rate __________.
What is the chemical significance of the amino acid R-groups (side chains) located specifically within the active site?
If enzymes were absent from a cell, what would be the most likely effect on its biochemical reactions?
It involves a different sequence of molecular interactions that requires less activation energy () to reach the transition state.
It increases the internal energy of the substrate molecules until they match the original activation energy requirement.
It alters the chemical nature of the products so that they are at a lower energy level than the reactants.
It eliminates the need for the reactants to reach a transition state before becoming products.
as a part of the product
chemically changed
chemically unchanged
completely denatured
significantly faster due to less interference
that remains exactly the same
too slow to sustain life
that depends only on the cell's volume
They determine the color of the enzyme protein
They are discarded by the enzyme after every reaction cycle
They are used to synthesize new DNA during catalysis
They provide the specific chemical environment and contacts needed to interact with the substrate
They would continue at the same rate but use more ATP
They would happen far too slowly for life to function
They would produce toxic byproducts instead of useful ones
They would proceed too quickly and overheat the cell
