Enzymes Questionbank

The overall three-dimensional folding of the protein's tertiary structure

The total number of amino acids in the polypeptide chain

The concentration of substrate molecules in the reaction medium

The temperature of the environment in which the reaction occurs

It involves a different sequence of molecular interactions that requires less activation energy ($E_a$) 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.

To precisely position key chemical groups to facilitate the reaction

To move the enzyme through the cytoplasm via motor proteins

To permanently lock the substrate inside the enzyme structure

To signal the cell to produce more enzymes

as a part of the product

chemically changed

chemically unchanged

completely denatured

True, because catalytic residues are distinct from binding residues

False, because any substrate that fits into the active site must undergo a reaction

True, but only if the change occurs at an allosteric site

False, because any change to the amino acid sequence will prevent substrate binding

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

It is consumed during the reaction and must be replaced.

It is permanently altered and cannot be used again.

It remains chemically unchanged and can be reused.

It is converted into a product of the reaction.

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

They provide the thermal energy needed to overcome the $E_{\text{a}}$.

They eliminate the $E_{\text{a}}$ entirely.

They lower the $E_{\text{a}}$, allowing the reaction to reach the transition state more easily.

They increase the $E_{\text{a}}$ to make the reaction more controlled.