Cell Theory:
Fundamental unit of structure, function, and organization in all living organisms.
Differentiation:
Process by which cells become specialized for specific functions.
Tissues:
Collections of similar specialized cells performing specific functions.
Types include epithelial, skeletal muscle, and nervous tissue.
Organs:
Collections of tissues performing specific physiological functions.
Organ Systems:
Groups of organs organized into systems (e.g., cardiovascular, respiratory, muscular, nervous systems).
Cell Organelles:
Prokaryotic Cells (e.g., bacterial cells):
Key structures include nucleoid, plasmids, 70S ribosomes, capsule, cell wall.
Eukaryotic Cells (plant and animal):
Structures include:
Plasma membrane
Cytoplasm
Nucleus, nucleolus
Endoplasmic reticulum (smooth and rough)
Golgi apparatus
Vesicles, lysosomes
Mitochondria, centriole, 80S ribosomes.
Plant-Specific Structures:
Cell wall, chloroplasts, vacuole, tonoplast, amyloplasts, plasmodesmata, pits.
Identification:
Recognize cell organelles using light microscopes and electron micrographs.
Light Microscopy:
Advantages and limitations of using light microscopes explored.
Understand how to calculate magnification using formulas (e.g., measured size = actual size × magnification).
Examples of Specialised Cells:
Palisade Mesophyll Cells:
Major site of photosynthesis.
Features include cylindrical shape, close packing for gas exchange, thin cell walls for gas diffusion, large vacuole, chloroplast positioning to maximize light absorption, and cytoskeleton movement of chloroplasts.
Sperm and Egg Cells:
Sperm Cell:
Contains nucleus with 23 chromosomes, acrosome for penetrating egg membrane, numerous mitochondria for energy, a tail for motility.
Egg Cell:
Contains large cytoplasm for energy store, protective outer membrane, and corona radiata.
Root Hair Cells:
Large surface area for absorption, channels and proteins for ion movement, mitochondria for active transport, thin cell wall for easy diffusion.
White Blood Cells:
Involved in immunity; includes T cells and B cells which have specific structure-function relationships.
Epithelial Tissue:
Squamous Epithelium:
Alveolar epithelium role in gas exchange; affected by conditions like COPD:
Chronic Bronchitis:
Thickening of squamous epithelium, mucus overproduction.
Emphysema:
Damage to alveoli, reduced surface area for gas exchange.
Columnar Epithelium:
Goblet and ciliated cells in lungs protect against pathogens by trapping and moving them out.
Endothelial Tissue:
Lines blood vessels; critical for regulating blood flow and pressure, especially in atherosclerosis.
Skeletal Muscle Fiber Structure:
Muscle fibers are multinucleated, striated, with specialized structures (myofibrils, sarcomeres).
Muscle Fiber Types:
Differences between fast and slow-twitch fibers regarding contraction rates, fatigue, and suitability for activities.
Neurones:
Differences between myelinated and non-myelinated neurons.
Mechanism of nerve impulse conduction (action potential) through changes in membrane permeability and saltatory conduction.
Nucleus:
Contains genetic material and organizes cell activities.
Mitochondria:
Generate ATP; central to cellular respiration.
Endoplasmic Reticulum (ER):
Smooth ER synthesizes lipids; Rough ER with ribosomes synthesizes proteins.
Golgi Apparatus:
Modifies, packages proteins, and produces lysosomes.
Ribosomes:
Synthesize proteins, can be free in cytoplasm or associated with RER.
Prokaryotic vs Eukaryotic Cells:
Prokaryotic cells: smaller, no nucleus, usually unicellular.
Eukaryotic: larger, with membrane-bound organelles, can be multicellular.
Focus on understanding organelle structures and functions.
Be able to calculate magnifications and sizes based on images.
Practice identifying cell types and their specializations.