ASAP500__Cell_Anatomy__Physiology_2023__3___3___4_

Page 1: Title

  • ASAP500

  • Cell Anatomy & Physiology

Page 2: Recall...

  • C:

  • D:

  • F:

  • E:

  • A:

  • B:

Page 3: Objectives

Part A: Generalised Cell

  • Identify the major components of a generalised human cell.

  • Describe the structure of each component and relate this to its function.

Part B: Cellular Transport

  • Explain the difference between active and passive cellular transport.

Page 4: Cell Diversity

  • Different types of cells exist due to specialization.

  • Example cell types include:

    • Sperm cell

    • Smooth muscle cell

    • Nerve cell

    • Red blood cell

    • Epithelial cell

Page 5: Commonalities in Cells

  • All cells in the body exhibit common features.

  • The lecture introduces structures and organization of a generalised human cell.

Page 6: Cell Organisation

Major Components of a Human Cell

  • Cell membrane

  • Cytoplasm:

    • Composed of organelles and cytosol.

  • Nucleus

  • Key organelles:

    • Ribosomes

    • Endoplasmic Reticulum

    • Golgi Complex

    • Lysosomes

    • Mitochondria

Page 7: Cell Membrane

Structures of the Cell Membrane

  • Main structures:

    • Lipid Bilayer: Double layer mainly of phospholipids and cholesterol.

    • Proteins: Extend into or through the lipid bilayer.

Functions

  • Provides shape to the cell.

  • Protects the cell.

  • Controls entry and exit of substances.

Page 8: Phospholipids and Glycolipids

  • Phospholipids:

    • Polar heads (hydrophilic)

    • Fatty acid tails (hydrophobic)

  • Glycoprotein: Carbohydrate + Protein

  • Glycolipid: Carbohydrate + Lipid

  • Integral (transmembrane) and peripheral proteins play crucial roles in cell function.

Page 9: Cilia

Modifications to the Cell Membrane

  • Cilia: Short, hair-like projections that:

    • Move fluids along cell surface (e.g., mucus in respiratory tract).

    • Facilitate movement of egg along uterine tubes.

Page 10: Microvilli

  • Microvilli: Finger-like projections that:

    • Increase surface area for absorption.

    • Found in the small intestine to optimize digestion of nutrients.

Page 11: Cytoplasm Composition

  • Composed of:

    • Cytosol: Fluid portion (mainly water) that surrounds organelles, site of many chemical reactions.

    • Organelles: Structures with distinct shapes and functions, located between membrane and nucleus.

Page 12: Ribosomes

Ribosome Structure and Function

  • Ribosomes are small structures made from proteins and rRNA.

  • Functions:

    • Synthesizes proteins.

    • Free ribosomes produce proteins for intracellular use.

    • Attached ribosomes (on endoplasmic reticulum) produce proteins for extracellular use (e.g., hormones like insulin).

Page 13: Mitochondria

Mitochondria as Powerhouses

  • Known for generating ATP through aerobic respiration.

  • ATP provides energy for functions such as:

    • Protein synthesis.

    • Ion transport across membranes.

  • More mitochondria found in energy-demanding cells (e.g., muscle, liver, brain).

Page 14: Mitochondrial Structure

  • Components include:

    • Outer mitochondrial membrane

    • Inner mitochondrial membrane

    • Matrix

    • Cristae

Page 15: Nucleus

Functions of the Nucleus

  • Acts as the control center of the cell.

  • Regulates cellular events and timing.

  • Contains genetic information in:

    • Genes: Hereditary units containing instructions for cell function.

    • Chromosomes: Long DNA molecules combined with proteins.

Page 16: Nuclear Structure

Nuclear Components

  • Nuclear envelope: surrounds nucleus

  • Nucleolus: produces ribosomal RNA

  • Chromatin: forms chromosomes

Page 17: Recap on Learning Objectives

  • Determine major components of a generalised human cell.

  • Relate structure to function.

  • Understand cellular transport mechanisms.

Page 18: Importance of Cellular Transport

  • Essential for nutrient (e.g. glucose) and waste (e.g. CO2) exchange.

Page 19: Membrane Permeability

Substances and the Membrane

  • Permeable to:

    • Oxygen (O2), carbon dioxide (CO2), small lipid-soluble molecules.

  • Impermeable to:

    • Glucose, water (H2O).

  • Transmembrane proteins assist with the transport of essential substances.

Page 20: Passive vs Active Processes

Types of Membrane Transport

  • Passive processes: No energy input needed; substances move down their concentration gradient.

  • Active processes: Requires energy (ATP); substances move against their concentration gradient.

Page 21: Overview of Transport Mechanisms

Passive Processes

  • a) diffusion

  • b) facilitated diffusion

  • c) osmosis

Active Processes

  • a) active transport

  • b) endocytosis (phagocytosis & pinocytosis)

  • c) exocytosis

Page 22: Additional Learning Resources

  • Available on Moodle:

    • Drag and drop exercise

    • Mind-map of cellular structures and functions

  • Reading: Pages 60-86 of "Principles of Anatomy and Physiology"