Enzymes and Biological Processes Quiz

What are enzymes primarily made of?

• Nucleic acids

• Lipids

• Proteins

• Carbohydrates

Answer explanation

Enzymes are primarily made of proteins, which are essential for catalyzing biochemical reactions. Other macromolecules like nucleic acids, lipids, and carbohydrates serve different functions in the body.

What is the primary function of enzymes in biological reactions?

• To change the products

• To speed up reactions

• To act as a reactant

• To slow down reactions

Answer explanation

The primary function of enzymes is to speed up biological reactions by lowering the activation energy required, thus facilitating the process without changing the products or acting as reactants.

Which model explains enzyme specificity?

• Fluid mosaic model

• Lock and key model

• Bohr model

• Induced fit model

Answer explanation

The lock and key model explains enzyme specificity by suggesting that the enzyme's active site (the 'lock') is precisely shaped to fit a specific substrate (the 'key'), ensuring only the correct substrate can bind.

What would happen to digestion without enzymes?

• It would take 2-3 weeks to digest a meal

• It would be faster

• It would not occur

• It would take 1-2 hours

Answer explanation

Without enzymes, digestion would be extremely slow, taking 2-3 weeks to break down food. Enzymes are crucial for speeding up chemical reactions in digestion, making nutrient absorption efficient.

Enzymes are necessary for which type of reactions?

• Metabolic reactions

• Nuclear reactions

• Combustion reactions

• Photosynthesis

Answer explanation

Enzymes are crucial for metabolic reactions as they act as catalysts, speeding up biochemical processes necessary for life. They are not involved in nuclear or combustion reactions, nor are they directly responsible for photosynthesis.

What is the role of enzymes in metabolic reactions?

• To inhibit reactions

• To act as a substrate

• To provide energy

• To maintain reaction speeds

Answer explanation

Enzymes are biological catalysts that speed up metabolic reactions by lowering the activation energy required. This allows reactions to occur more quickly and efficiently, thus maintaining reaction speeds essential for life.

What is the term for the molecule that an enzyme acts upon?

• Product

• Substrate

• Catalyst

• Inhibitor

Answer explanation

The term for the molecule that an enzyme acts upon is called the substrate. Enzymes bind to substrates to catalyze biochemical reactions, transforming them into products.

What happens to enzymes after a reaction?

• They are used up

• They are changed

• They remain unchanged

• They become inactive

Answer explanation

Enzymes act as catalysts in reactions and are not consumed or altered in the process. After a reaction, they remain unchanged and can participate in multiple reactions, making them efficient biological catalysts.

Which of the following is NOT a characteristic of enzymes?

• They speed up reactions

• They are used up in reactions

• They are biological catalysts

• They are proteins

Answer explanation

Enzymes are not used up in reactions; they act as catalysts and can be reused. They speed up reactions, are biological catalysts, and are typically proteins, making 'They are used up in reactions' the incorrect characteristic.

What is the effect of enzymes on the rate of chemical reactions?

• They stop the reaction

• They increase the rate

• They have no effect

• They decrease the rate

Answer explanation

Enzymes act as catalysts, lowering the activation energy required for reactions, which increases the rate of chemical reactions. Therefore, the correct answer is that they increase the rate.