1. Ian Anderson (2013)
Saint Ignatius College Geelong
01. Life at the cellular level.

2. Key knowledge & skills
 Outline the cell theory.
 Compare prokaryotic and eukaryotic cells at light and
electron microscope levels.
 List the specialised parts of cells and describe their
roles.
 State the main differences between plant and animal
cells.

3. Cell theory.
 All living things are made of
cells.
 All cells come from pre-
existing cells.
 Cells are the basic building
blocks of all life.

4. Holds true for all
living things.
From simple,
unicellular organisms.
Cell theory.

5. To the more complex
multicellular
organisms.
Cell theory.

6. Cell theory.
To understand life you need to understand how cells
work.
 Even though cells are specialised for many different
purposes, they share some common features.
 They all have a similar cell structure.
 They all perform similar basic functions.
 They are all made up of ‘the molecules of life’.

8. Looking at cells.
Light microscopes
 Magnify up to 1000-2000 times.
Electron microscopes.
 Magnify up to 2 million times.
 Transmission v scanning electron
microscopy
Synchrotron.
 Magnification to molecular level!

9. Cell structure.
Cells can be classified into two major types based on
their level of cell structure.
 Prokaryotic cells.
 Eukaryotic cells.

10. Prokaryotic cells.
(pro = before; karyotic = a nucleus).
 Small, primitive cells.
 Lack membrane-bound organelles.
 Have a single circular DNA chromosome.
 In addition, can also have several small circles of DNA called
plasmids.
 Have a cell wall.
 e.g. bacteria & cyanobacteria

11. Eukaryotic cells.
(eu= with; karyotic = a nucleus).
 More advanced & usually larger than prokaryotic cells.
 Contain membrane-bound organelles.
 Distinct nucleus and other organelles.
 e.g. plants, animals, fungi, protista.

12. Eukaryote organelles.
Organelles you need to know the function of.
Plasma membrane Ribosomes
Nucleus Vacuole
Mitochondrion Cilia & flagellum
Endoplasmic reticulum Plastids
-Chloroplasts
-Leucoplasts
-Chromoplasts
Golgi apparatus Centrioles
Lysosome

13. Eukaryote organelles.
Organelle Function
Plasma membrane Controls entry of substances into and out of the cell.
Nucleus Contains genetic material and controls cellular
activities.
Mitochondrion Involved in the energy transformations that release
energy for the cell.
Endoplasmic reticulum A network of intracellular membranes forming
channels through which proteins are moved.
Golgi apparatus Packages the protein into vesicles for transport across
the plasma membrane and out of the cell.
Lysosome Membrane bound vesicles containing digestive
enzymes.

14. Eukaryote organelles.
Organelle Function
Ribosomes Sites of protein synthesis. (also found in prokaryotes)
Vacuole Membrane bound organelle. In plants – usually large
and help maintain water balance within the cell and
provide turgidity. In animals – usually smaller and
involved in intracellular digestion or water balance.
Cilia & flagellum Involved with movement.
Plastids
-Chloroplasts
-Leucoplasts
-Chromoplasts
Chloroplasts – site of photosynthesis; leucoplasts –
store starch, oil or proteins; and chromoplasts –
coloured plastids found in fruits and flowers.
Centrioles Points of attachment for the spindle fibres during
mitosis.

15. Eukaryote organelles.
Electron micrograph of a liver cell (x9000)
Source: Walpole et al. (2011)

16. Plant v animal cells.
 All plant cells contain a cell wall outside the plasma
membrane. Made of cellulose. Provides structural
support and is permeable to most substances. Animal
cells do not have a cell wall.
 Plastids are often found in plants, but never in animal
cells.
 Vacuoles can be found in both plant and animal cells,
In plant cells, often large and play key role in
maintaining osmotic balance. In animal cells, never
large.
 Centrioles are only found in animal cells.

17. The inner life of a cell.