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"