Understanding Enzymes and Their Functions

Aug 4, 2024

General Biology 1: Week 7 - Structure and Functions of Enzymes

Introduction

  • Greetings and acknowledgments to students and teachers from various schools.
  • Week 7 topic: Structure and Functions of Enzymes.
  • Global Media and Information Literacy Week by UNESCO.
  • Importance of validating sources, corroborating information, and understanding content creation to identify credible scientific information.

Review from Last Week

  • Cell membrane functions: transport materials into and out of the cell due to its unique structure.
  • Mechanisms of membrane transport: Passive (simple diffusion, osmosis, facilitated diffusion) vs. Active (primary active transport, endocytosis, exocytosis).

Competencies for This Week

  • Describe the components of an enzyme.
  • Explain oxidation and reduction reactions.
  • Determine the effects of pH, temperature, and substrate concentration on enzyme activity.

Origin of Life: Primordial Soup Theory

  • Early Earth's harsh conditions with methane-rich atmosphere and stormy climate led to the formation of biomolecules like amino acids and proteins.
  • Stanley Miller-Urey experiment simulated early Earth conditions, supporting the primordial soup theory by producing amino acids.

Proteins and Amino Acids

  • Proteins: Organic compounds composed of amino acids linked by peptide bonds.
  • Amino acids: Building blocks of proteins, consisting of a central carbon atom, amino group (NH2), carboxyl group (COOH), and a variable R side chain.
  • Protein structures: Primary (amino acid chain), Secondary (folds due to main chain interactions), Tertiary (3D structure from side chain interactions), Quaternary (multiple amino acid chains, e.g., hemoglobin).

Enzymes

  • Enzymes: Proteins that catalyze chemical reactions by lowering activation energy.
  • Examples: Salivary amylase, pepsin, trypsin, kinases, ligases.
  • Structure: Composed of a protein scaffold, active site (binding site + catalytic site), where substrate binds.
  • Models of enzyme action: Lock and Key (exact fit) vs. Induced Fit (active site adjusts to substrate shape).

Redox Reactions

  • Redox (Reduction-Oxidation) reactions involve the transfer of electrons.
  • Mnemonics: Leorara (Losing Electrons Oxidation, reducing agent) and Gerowaowa (Gaining Electrons Reduction, oxidizing agent).
  • Applications: Batteries, combustion, photosynthesis, cellular respiration.

Factors Affecting Enzyme Activity

  • Substrate concentration: Directly proportional to reaction rate until enzyme saturation.
  • Enzyme concentration: Reaction rate increases as long as substrate is available.
  • Other factors: pH, temperature.

Assessment

  1. R group of amino acids varies (Answer: A).
  2. Incorrect statement about redox reactions: Oxidizing agents are atoms that lost electrons (Answer: C).
  3. Active site binds with substrate (Answer: A).
  4. Optimum pH value results in highest enzyme activity (Answer: C).

Conclusion

  • Positive attitude as catalyst for positive outcomes.
  • Feedback and support for Team Mahusay Senior High School Science and Technology.

Announcements

  • Next session on November 8th.
  • Up next: Alternative Learning System and Mommy Tech Talks tutorial.