A closer look at cells and their organelles for Year 10 students at Saint Ignatius College Geelong

1. GENETICS.
01. A closer look at cells.
Ian Anderson
Saint Ignatius College Geelong

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.
Source: http://www.history-of-the-microscope.org

4.  Holds true for all
living things.
 From
simple, unicellular
organisms.
Cell theory.
Source:
http://webhome.broward.edu//~ssimpson/JMDelvecchio-
Paramecium.htm

5.  To the more
complex
multicellular
organisms.
Cell theory.
Source:
http://en.wikipedia.org/wiki/File:Animal_diversity_Octo
ber_2007.jpg

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’.

7. 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!

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

9. 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.
Source:
http://michaeldomingos.hubpages.com/hub/The-
Mechanism-Behind-BacterialProkaryotic-Motility

10. 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.
Source: http://leavingbio.net/cell%20structure_files/cell%20structure.htm

11. 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.
Ribosomes Sites of protein synthesis. [Also found in
prokaryotes].

12. EUKARYOTE ORGANELLES.
Organelle Function
Lysosome Membrane bound vesicles containing digestive
enzymes.
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.
Chloroplasts Site of photosynthesis.
Centrioles Points of attachment for the spindle fibres during
mitosis.

13. EUKARYOTE ORGANELLES.
Electron micrograph of a liver cell (x9000)
Source: Walpole et al. (2011)

14. PLANT V ANIMAL CELLS.
Source:
http://www.phschool.com/science/biology_place/biocoach/cells/review3.html

15. 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.
 Chloroplasts 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.

16. THE INNER LIFE OF A CELL.
Source: https://www.youtube.com/watch?v=wJyUtbn0O5Y

17. http://SICkScience10.wikispaces.com/