Topics 3.1 - 3.3 Enzymes

Front

How enzymes work:

Back

They lower the activation energy of the reaction to increase the reaction rate.

Answer explanation

Enzymes work by lowering the activation energy of a reaction, which increases the reaction rate. This allows the reactants to convert to products more easily without altering the energy of the reactants or products.

Front

Type of macromolecule for enzymes?

Back

Protein

Answer explanation

Enzymes are biological catalysts that speed up chemical reactions in the body. They are primarily made of proteins, which are macromolecules composed of amino acids. Therefore, the correct answer is Protein.

Front

Enzymes consist of repeating monomers.

Back

Amino acids

Answer explanation

Enzymes are biological catalysts composed of amino acids, which are the repeating monomers that link together to form proteins. Other options like monosaccharides and nucleotides are not involved in enzyme structure.

Front

Part of enzyme where substrate bonds: _____

Back

active site

Answer explanation

The part of the enzyme that the substrate bonds to is called the active site. This region is specifically shaped to fit the substrate, facilitating the biochemical reaction.

Front

Energy required to initiate a reaction

Back

activation energy

Answer explanation

The energy needed to start a reaction is called activation energy. It is the minimum energy required for reactants to undergo a chemical reaction, making it essential for initiating the process.

Front

Not true about enzymes:

Back

Enzymes can only be used once in a chemical reaction.

Answer explanation

The statement "Enzymes can only be used once in a chemical reaction" is NOT true. Enzymes can be reused multiple times after catalyzing a reaction, which distinguishes them from other catalysts.

Front

Shape of an enzyme/protein is determined by:

Back

Amino acid sequence and properties of amino acids.

Answer explanation

The shape of an enzyme/protein is determined by its amino acid sequence and the properties of those amino acids, which dictate how the protein folds. Other factors like temperature and pH can affect stability but not the inherent shape.

Front

Energy is released from ATP when a phosphate group is removed.

Back

a phosphate group is removed

Answer explanation

Energy is released from ATP when a phosphate group is removed. This process, known as hydrolysis, breaks the bond between the second and third phosphate groups, releasing energy for cellular activities.

Front

Cyanide halts ATP production in mitochondria, acting as a:

Back

inhibitor

Answer explanation

Cyanide inhibits the function of mitochondria, preventing ATP production. Therefore, it acts as an inhibitor, blocking the normal biochemical processes necessary for energy production in cells.

Front

Energy transformation always increases ______________

Back

entropy of the universe

Answer explanation

The correct answer is 'entropy of the universe' because, according to the second law of thermodynamics, whenever energy is transformed, the total entropy of the universe always increases, indicating a tendency towards disorder.