Question

What is the reactant for each of the following enzymes? a. peptidase b. cellulase c. lactase

Short answer

Peptidase: peptides, Cellulase: cellulose, Lactase: lactose

Step-by-step solution

Understand Peptidase

Peptidase is an enzyme that breaks down peptides into amino acids. Therefore, the reactant for peptidase is peptides.

Understand Cellulase

Cellulase is an enzyme that breaks down cellulose into simpler sugars like glucose. Thus, the reactant for cellulase is cellulose.

Understand Lactase

Lactase is an enzyme that breaks down lactose into glucose and galactose. Hence, the reactant for lactase is lactose.

Key concepts

Peptidase

Peptidase is an enzyme that plays a crucial role in the digestive system, breaking down proteins into amino acids. Proteins are made up of smaller units called peptides.

The function of peptidase is to cleave these peptides into their constituent amino acids. This process is essential for the body to absorb and use the proteins we eat. Without peptidase, we wouldn't be able to utilize the proteins in our diet effectively.

For example, when you eat a piece of chicken, peptidase helps break it down into amino acids that your body can use.

Cellulase

Cellulase is an enzyme that is particularly important in breaking down cellulose. Cellulose is a complex carbohydrate found in the cell walls of plants. It's what gives plants their structure and rigidity.

When cellulase breaks down cellulose, it converts it into simpler sugars like glucose. This process is vital for organisms that rely on plant material for their energy needs.

For instance, herbivorous animals and certain microorganisms produce cellulase to digest plant matter. Humans also benefit from cellulase found in foods like fruits and vegetables, although we don't naturally produce it in our digestive systems.

Lactase

Lactase is an enzyme that specializes in breaking down lactose, the sugar found in milk and dairy products. When lactase breaks down lactose, it converts it into two simpler sugars: glucose and galactose.

These simpler sugars are easier for the body to absorb and use for energy.

However, not everyone produces enough lactase. This can lead to lactose intolerance, a condition where people have difficulty digesting dairy products. Symptoms can include bloating, gas, and diarrhea. Lactase supplements are often used to help people with this condition.

Enzyme-Substrate Specificity

Enzyme-substrate specificity refers to the unique relationship between an enzyme and its substrate (the reactant it acts on). Each enzyme is specific to a particular substrate, much like a key fits into a specific lock.

This specificity is due to the enzyme's active site, a special region where the substrate binds. The shape and chemical environment of the active site are perfectly suited to interact with the substrate.

For example, peptidase only acts on peptides, cellulase only breaks down cellulose, and lactase specifically targets lactose. This specificity ensures that biochemical reactions proceed with high efficiency and minimal errors.