LS 10 Week 4 – 6 The Basic Units of Life
3 weeks (12 hours)
Cells: The Basic Units of Life
Cells are mostly made up of proteins, carbohydrates, lipids, nucleic acids and water.
Brief overview of the history of microscopy: from lens and light microscopes and to electron microscopes. How these instruments enabled people to see cells and then structures within cells which led to cell theory.
(Briefly revise Grade 9 work on the cell.)
Cell Structure and Function: The Roles of Organelles
- cell wall – support structure in plant cells only;
- cell membrane – fluid mosaic model, boundaries and transport: movement across membranes: diffusion, osmosis and active transport;
- nucleus, chromatin material, nuclear membrane, nucleopores, nucleolus: the control centre, heredity;
- cytoplasm – storage and circulation of materials;
- mitochondria – release energy during cell respiration;
- ribosomes – protein synthesis;
- endoplasmic reticulum (rough and smooth) – transport systems;
- Golgi body – assembles secretions;
- plastids – production and storage of food and pigments; and
- vacuole, lysosomes, vesicles – storage, digestion and osmoregulation
Relate structure and location of organelles to their functions.
(This is an introduction; some organelle functions will be explored in more detail in other sections.)
Cells differ in size, shape and structure in order to carry out specialised functions [link to tissues].
The differences between plant and animal cells (link to Grade 9).