1. Ch 8
Cell Structure

2. Syllabus
Describe the function of & identify the: mitochondria, chloroplast, nucleus, nuclear pores, ribosomes & DNA.

3. The Cell
The cell is the basic unit in living things.

4. Plant Cell as seen under
a light microscope

5. Cells All living things are composed of one or more cells.
Cells are the basic units of structure and function in living organisms.
Cells come only from reproduction of existing cells.

6. Cytoplasm Cytoplasm is a clear jelly like fluid that fills the cell
It is the medium for all the chemical reactions
It contains all the organelles suspended within the cell.

7. Organelles
An organelle is a structure found in a cell that carries out a specific function.

8. Organelles we need to know
Cell membrane
Nucleus
Mitochondria
Chloroplast
Ribosomes
DNA
Cell Wall
Vacuole

9. Learning Check What are Cells? What are organelles?
Can you name 8 organelles?

10. Animal Cells contain the following structures: Cell Membranes
Mitochondria
Nucleus
Cytoplasm
Only the cell membrane, the cytoplasm and the nucleus can be seen under the light microscope.

11. Ultra Structure of an animal cell

12. Cell / Plasma Membrane are made up of phospholipids and proteins.
are semi permeable / selectively permeable - controls the entry and exit of molecules to the cell.
surrounds the cell
function is to control the entry and exit of molecules to the cell

14. Learning Check All cells have a cell membrane.
What are they composed of?
What are its functions?

15. Plant Cells Plant cells also contain other organelles: Cell walls
Chloroplasts
Large Vacuoles

16. Ultra structure of an plant cell

17. Cell wall The cell wall is
composed of cellulose fiber, polysaccharides and proteins
rigid, this gives plant cells a very defined shape
gives support, strengthens and prevents the cell from bursting.

18. Vacuoles
Vacuoles are membrane-bound sacs found within the cytoplasm of a cell
They provide
1. structural support
2. Storage of water, food and chemicals,
Plant cells have larger vacuoles

19. Mitochondria function is to provide energy (respiration)
Cells e.g. muscles with lots of mitochondria produce a lot of energy

20. Ribosomes
Contain RNA & protein
Their function is to make proteins

21. Chloroplasts
only in plants
are green and carry out photosynthesis

22. Learning check What organelle carries out photosynthesis?
What type of cells have large vacuoles and cell walls?
What is the function of vacuoles?
What is the function of cell walls?
What makes cells walls rigid?

23. Nucleus function is to control the cell
contains chromosomes which are made of DNA
elongated, non-dividing chromosomes are called chromatin

24. DNA deoxyribonucleic acid
found in chromosomes or chromatin in the nucleus

25. Nucleolus
located in nucleus
makes ribosomes

26. Prokaryotic cells
do not have a nucleus or membrane-enclosed organelles
are small and more primitive
are found as bacteria

27. Eukaryotic cells have a membrane-enclosed nucleus and cell organelles
are larger and more advanced
are found as plant and animal cells, fungi and amoeba