Enzymes

Glucose

Starch

Amino acid

Glycerol

Because enzymes are very large

Because enzymes are not used up in the reaction

Because enzymes turn into substrates

Because enzymes work very slowly

The enzyme and substrate have the same shape

The enzyme and substrate have shapes that fit together precisely

The enzyme is much larger than the substrate

The shapes repel each other

The part of the substrate that breaks

The region on the enzyme where the reaction happens

The energy required to start the reaction

The final product of the reaction

Component A

Component B

Component C

Component D

Starch

Glucose

Maltose

Protein

They provide the energy for the reactions

They allow reactions to occur quickly enough to sustain life at body temperature

They prevent the body from becoming too warm

They act as a source of amino acids for the body

A collision between an enzyme and substrate with sufficient energy and the correct orientation.

A collision that causes the enzyme to break apart into its individual amino acids.

Any collision between an enzyme and a substrate molecule, regardless of energy.

A collision between two enzyme molecules that allows them to share substrate molecules.

There are more active sites available, increasing the probability of a successful collision.

The enzyme molecules provide more kinetic energy to the substrate molecules.

Increasing enzyme concentration lowers the activation energy even further.

The enzymes aggregate to form larger complexes that are more efficient at catalysis.

The folding of the polypeptide chain creates an active site that matches the substrate's shape and charge.

The substrate's shape determines how the enzyme will fold after it is synthesized on the ribosome.

The tertiary structure is a rigid 'mold' that forces the substrate to change into the product.

The enzyme and substrate have identical shapes so that they can merge into one large molecule.

pH 2.1

pH 7.4

pH 11.5

pH 4.5

The amount of substrate available

The chemical bonds that determine the enzyme's shape

The temperature of the solution

The color of the enzyme

The enzyme is destroyed by the cold

The substrate molecules freeze solid

Molecules move slower, leading to fewer collisions

The active site becomes too large

The temperature

The pH

The rate of reaction

The time it takes for the reaction to finish

The enzyme is at its optimum pH.

The enzyme is being denatured by alkalinity.

The enzyme is being denatured by acidity.

The enzyme is at its optimum temperature.

Temperature graphs are always straight lines.

pH graphs are usually symmetrical, while temperature graphs show a sharp drop after the optimum.

Temperature graphs are symmetrical, while pH graphs are not.

There is no difference between the two graph shapes.

It decreases.

It stays the same.

It increases.

It becomes negative.

The high concentration of hydroxyl ions ($OH^-$) at pH 8.0 acts as a competitive inhibitor, blocking the active site of the pepsin molecules.

The change in pH alters the ionization of R-groups on both the enzyme and the protein substrate, preventing the formation of an enzyme-substrate complex.

The increase in pH causes the protein substrate molecules to move significantly faster than the enzyme, reducing the frequency of successful collisions.

Pepsin molecules are immediately hydrolyzed into individual amino acids by the alkaline environment, resulting in a permanent loss of primary structure.

The body cannot produce enough energy to reach $60^\circ C$.

Human enzymes are made of different amino acids than those in other organisms.

$37^\circ C$ is the temperature at which all chemical bonds are strongest.

Evolution has favored enzymes that are stable and efficient at the body's regulated core temperature.

Using a water bath to maintain a constant temperature.

Measuring the rate of reaction over the first 30 seconds (initial rate).

Failing to equilibrate the enzyme and substrate at the target temperature before mixing them.

Using the same concentration of enzyme for all trials.