Macromolecules and enzymes

How do enzymes affect the activation energy of a reaction?

• Enzymes increase the activation energy, making it harder for the reaction to occur.

• Enzymes have no effect on the activation energy of a reaction.

• Enzymes lower the activation energy, making it easier for the reaction to occur.

• Enzymes only affect the rate of the reaction, not the activation energy.

What is the role of carbohydrates in living organisms?

• Carbohydrates are primarily used for DNA replication.

• Carbohydrates provide energy, serve as structural components, and are involved in cell recognition.

• Carbohydrates are only used for energy storage.

• Carbohydrates are not essential for living organisms.

What is a lipid?

• A type of carbohydrate that provides energy.

• A diverse group of hydrophobic molecules, including fats, oils, and phospholipids, that store energy and make up cell membranes.

• A protein that helps in muscle contraction.

• A vitamin that is essential for vision.

What is the active site of an enzyme?

• The part of the enzyme that determines its shape.

• The specific region of an enzyme where the substrate binds and the reaction occurs.

• The location where enzymes are produced in the cell.

• The area of the enzyme that is not involved in the reaction.

How can temperature and pH affect enzyme activity?

• They have no effect on enzyme activity.

• They can enhance enzyme activity by increasing substrate concentration.

• They can affect enzyme activity by altering the enzyme's shape and function, potentially leading to denaturation.

• They can only affect enzyme activity at extreme temperatures.

What is a substrate in the context of enzyme activity?

• A product formed after an enzyme reaction.

• A molecule that inhibits enzyme activity.

• The reactant molecule upon which an enzyme acts.

• A type of enzyme that speeds up reactions.

What are nucleic acids?

• Macromolecules that store and transmit genetic information, such as DNA and RNA.

• Small molecules that provide energy to cells.

• Proteins that help in the synthesis of hormones.

• Lipids that form the structure of cell membranes.

What is the lock and key model of enzyme action?

• The lock and key model describes how a specific substrate fits into the active site of an enzyme, similar to how a key fits into a lock.

• The lock and key model suggests that enzymes can change shape to fit any substrate.

• The lock and key model indicates that enzymes are not specific and can bind to multiple substrates.

• The lock and key model explains how enzymes are denatured by heat.

What are monosaccharides?

• The simplest form of carbohydrates, consisting of single sugar molecules like glucose and fructose.

• Complex carbohydrates made of multiple sugar units.

• A type of protein that helps in muscle building.

• Fats that are solid at room temperature.

What are the building blocks of proteins?

• Nucleotides

• Fatty acids

• Amino acids

• Monosaccharides