CAPE BIOLOGY Unit 1 Complete2

CAPE BIOLOGY UNIT ONE MANUAL NOTES

CAPE BIOLOGY UNIT ONE MANUAL NOTES

Module Overview

  • Module One: Cell and Molecular Biology

  • Topics:

    1. Aspects of Biochemistry

    2. Cell Structure

    3. Membrane Structure and Function

    4. Enzymes

Topic 1: Aspects of Biochemistry

Water as a Medium of Life

  • Water makes up more than 70% of cell mass.

  • Molecular structure: H2O (two hydrogen covalently bonded to oxygen) creates a dipole moment, enabling cohesion and hydrogen bonding.

  • Properties of water:

    • Thermal regulation: High specific heat.

    • Universal solvent: Interacts with ions and molecules.

    • Mass flow: Cohesion supports capillary action.

    • Reactivity: Hydrolysis in digestion and photosynthesis.

Carbohydrates

  • Definition: Organic molecules consisting of carbon, hydrogen, and oxygen.

  • Types of Carbohydrates:

    • Monosaccharides: Single units (e.g., glucose, ribose).

    • Disaccharides: Two units linked by glycosidic bonds (e.g., sucrose).

    • Polysaccharides: Long chains (e.g., starch, glycogen, cellulose).

Polysaccharides and Their Functions

  • Starch: Energy reserve in plants (amylose + amylopectin), stored in plastids.

  • Glycogen: Energy reserve in animals, stored in liver and muscles.

  • Cellulose: Structural support in cell walls, hard to digest.

Topic 2: Cell Structure

Cell Components

  • Animal vs. Plant Cells:

    • Animal cells: No cell wall, small vacuoles, centrioles present.

    • Plant cells: Cell wall present, large vacuoles, no centrioles.

Organelles and Functions

  • Nucleus: Contains DNA, surrounded by nuclear envelope.

  • Mitochondria: Site of aerobic respiration.

  • Chloroplasts: Site of photosynthesis in plants.

  • Ribosomes: Protein synthesis.

  • Endoplasmic Reticulum: Rough ER for protein synthesis, smooth ER for lipid synthesis.

  • Lysosomes: Digestion of waste materials.

Topic 3: Membrane Structure and Function

Fluid Mosaic Model

  • Plasma membrane composed of phospholipid bilayer with embedded proteins.

  • Functions: Facilitates transport and communication, maintains homeostasis.

Transport Mechanisms

  • Diffusion: Moving from high to low concentration.

  • Facilitated Diffusion: Involves carrier/channel proteins.

  • Active Transport: Requires ATP, moves against the concentration gradient.

  • Endocytosis/Exocytosis: Bulk transport of materials in/out of cells.

Topic 4: Enzymes

Enzyme Functionality

  • Enzymes are globular proteins, act as biological catalysts.

  • Enzyme action involves substrate binding at the active site, forming enzyme-substrate complex.

  • Factors influencing enzyme activity:

    • Temperature, pH, enzyme, and substrate concentration.

Inhibition

  • Competitive Inhibition: Inhibitor competes for active site.

  • Non-Competitive Inhibition: Inhibitors bind to other area on the enzyme.

Summary

  • Мanagement of biological processes through structures (organelles) and functions (metabolism, transport, enzyme reactions) is critical for understanding cellular life.