Enzymes and Metabolism

Enzymes and Metabolism

Learning Objectives

At the end of the lesson, you will understand the role of enzymes in metabolic processes.
At the end of the lesson, you will be able to distinguish between anabolic and catabolic reactions.
At the end of the lesson, you will recognize the structure and function of enzymes as globular proteins.
At the end of the lesson, you will comprehend the interactions between substrates and enzymes for catalysis.
At the end of the lesson, you will understand the effects of temperature, pH, and substrate concentration on enzyme activity.
At the end of the lesson, you will be able to describe the methods of measuring enzyme-catalyzed reactions.
At the end of the lesson, you will understand how enzymes affect the activation energy of chemical reactions.

What do you already know about enzymes and metabolism?

The role of enzymes in metabolism

Enzymes are biological catalysts crucial for metabolism, a network of chemical reactions in living organisms.

Anabolic and catabolic reactions

Metabolism consists of anabolic reactions that build larger molecules from smaller ones using energy, and catabolic reactions that break down larger molecules, releasing energy.

Enzymes as globular proteins with an active site

Enzymes are globular proteins with an active site where substrates bind, undergoing induced-fit binding which alters both the substrate and active site for catalysis.

Induced-fit model of enzyme binding

Enzyme activity is influenced by molecular motion, with substrate–active site collisions necessary for catalysis.

Molecular motion and substrate–active site collisions

Enzyme–substrate specificity is determined by the active site's shape and chemical properties, with denaturation occurring when the enzyme's structure is altered beyond repair.

Effects of temperature, pH, and substrate concentration on enzyme activity

Temperature, pH, and substrate concentration significantly affect enzyme activity, each with an optimal range for maximum activity.

Measurements in enzyme-catalyzed reactions

Enzyme-catalyzed reactions are measured by monitoring changes in substrate or product concentration over time.

Effect of enzymes on activation energy

Enzymes lower the activation energy required for reactions, increasing reaction rates without altering the net energy released.

Key Definitions

Metabolism: The set of life-sustaining chemical transformations within the cells of living organisms.
Anabolic Reactions: Metabolic reactions that construct molecules from smaller units, requiring energy input.
Catabolic Reactions: Metabolic reactions that break down molecules into smaller units and release energy.
Enzymes: Proteins that act as biological catalysts to speed up chemical reactions without being consumed.
Active Site: The region on an enzyme where substrate molecules bind and undergo a chemical reaction.
Induced-Fit Binding: A model describing how enzyme and substrate undergo shape changes for effective binding and catalysis.
Denaturation: The process by which a protein loses its three-dimensional structure and function, often irreversible.
Activation Energy: The minimum quantity of energy that the reacting species must possess in order to undergo a specified reaction.

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.