1. Cell Structure
The Microscope

2. Introduction - Microscope
Discovery of Micro-organisms
Allows us to look at cells
Has lead to discoveries in many diseases
Cytology - the study of cells
Light Microscope
Electron Microscope
Beams of Light
Beams of electrons
X 1500
X 500,000

3. The Light Microscope
You Must be able to label a microscope & state its functions

4. Functions of Microscope
Eyepiece lens - magnifies the image
Course adjustment - rough adjustment
Fine adjustment - precise focusing
Nosepiece - revolves lens into position
Objective lens - magnifies image
Stage - holds the slide
Light source - sends light through the slide
Clips - hold the slide in place

5. Basic Cell Structure
Plant or Animal Cells???

6. Cell Ultra – Structure (Animal)

7. Cell Ultra – Structure (Plant)

8. Cell Membrane Phospholipids and and proteins bi-layer FUNCTIONS:
Controls movement of substances in & out of cell.
Production of anti-bodies
Support
Structure

9. Cell Wall Only found in plant cells. Made by the cytoplasm.
Made of cellulose
Fully Permeable
Functions
Support
Protection
Middle Lamella:
A chemical material which 'glues' plant cells together.
It is produced during cell division.

10. The Nucleus The nucleus is the control centre of the cell. Structure
Nuclear membrane
Nuclear pores
Nucleoli - manufacture proteins
Chromosomes/chromatin

11. The Nucleus The nucleus is the control centre of the cell. Functions
Cell division - mitosis/meiosis
Protein synthesis
Controls activities of the cell

12. Mitochondria
Most are found in active cells like muscle cells, nerve cells etc…
Used in plant and animal cells for respiration.
Produces a large number of enzymes.
matrix
cristae

13. Chloroplasts Only found in plant cells Contain pigment chlorophyll
Used during photosynthesis to absorb sunlight

14. Ribosomes Produced by the nucleolus in the nucleus.
Tiny, but very numerous.
Either floating freely in cytoplasm or attached to endoplasmic reticulum.
Protein synthesis.
Sometimes they may be attached together in a group called a 'polysome'.

15. Centrioles Mainly found in animal cells.
Occur in pairs near the nucleus.
Function
Cell division

16. Vacuole Mainly in plant cells.
Found in some animal cells such as Amoeba.
Controls the water content of the cell.
Contains food/excretory products (sap)

17. Endoplasmic Reticulum
A network of canals in the cells which serves as a transport system.
Store food materials such as proteins, fats, carbohydrates, vitamins and minerals.
Sometimes there are ribosomes attached to the outside of the E.R. - these are called Rough Endoplasmic Reticulum.
When there are no ribosomes attached they are called Smooth Endoplasmic Reticulum.

18. Golgi Apparatus: Sometimes called Golgi Bodies.
Functions are bile production, mucous and synovial fluid secretion, eye pigment, enamel, keratin (nails and hair protein) and the production of cell membranes

19. Differences in Plant & Animal Cells
Plants
Animals
Cell Walls
No Cell Walls
Chloroplasts
No chloroplasts
Chlorophyll
No chlorophyll
Large Vacuoles
Small (if any) vacuoles

20. Prokaryotic and Eukaryotic Cells
cells that contain a nucleus bound by a nuclear membrane.
They also contain many membrane bound structures called organelles.

21. Prokaryotic and Eukaryotic Cells
Prokaryotic cells
Cells that do not have a nucleus bound by a nuclear membrane.
Instead of having DNA fixed on chromosomes their genetic information is on a circular loop called a plasmid.
Example - bacteria cell.

22. Mandatory Experiments
To prepare an examine a plant cell, stained & unstained using a light microscope
a. Plant cell – onion, get the thin epidermis between layers of the onion to allow light pass through
b. Stain – iodine, shows up membranes
c. Apply cover slip at an angle to prevent air bubbles
d. Start the procedure at low power to find the cell and prevent damage to the microscope
e. Be able to draw the results

23. Mandatory Experiments
To prepare and examine an animal cell using a light microscope
a. Animal cell – cheek cell
b. Spread the cells out thinly to allow the light to pass though
c. Dye – methylene blue, stains the nucleus dark blue
d. Apply cover-slip at an angle to prevent air bubbles
e. Start with low objective lens
f. Use fine focus on the high power to prevent damage to the microscope
g. Be able to draw results