The document discusses the history and development of microscopy and cell theory. It begins with early microscopes like hand lenses and single lens microscopes used to first observe cells. Today, electron microscopes like SEM and TEM are used. Key contributors included Hooke, who first observed cells, Leeuwenhoek who discovered bacteria and cells, and Schwann and Schleiden who developed the original cell theory. The document then describes plant and animal cell structures like cell walls, chloroplasts and organelles in detail. It explains membrane structure and transport mechanisms. The importance of microscopy in observing cells is also highlighted.

1. Refer to Campbell and Reece, 2010 –
Chapter 6 and 7 p. 96-123 and 125-
131, Edulink and learning guide notes

2.  The study of cells and micro organisms has
changed over time with the change in
technology.
 These were studied in the beginning with hand
lenses, single lens microscope, light
microscope
 Today we have electron microscopes.
 Two types of electron microscopes are used
today: SEM – Scanning electron microscope
and TEM – Transmission electron microscope.

3.  Developed a microscope
with one lens.
 Discovered
- bacteria
- blood cells
- spermatozoa
- protozoa

4.  Uses the concept cell
for the first time.
 He used it when he
looked at the
microscopic
structure of cork
cells.

5.  Describes the nucleus of a cell

6.  Developed the cell theory:
- Plants and animals are made of
groups of cells.
- The cell is the basic unit of living
organisms

7.  Expanded the cell theory:
 He said that new cells formed
by the division of existing cells

8.  Expanded the cell
theory more:
 He said that all
cells can be
traced to their
origin

9.  All living organisms are made out of cells
 New cells are formed by the division of
existing cells
 The cell houses genes, which are the
blueprint for growth, functioning and
development of cells
 The cell is the functional unit of life
because all chemical reactions of life take
place inside the cell

10.  A cell is the basic unit of
structure and function in
organisms.
 Cells differ in size, shape and in
function.
 A cell consist of smaller
structures called organelles.

11.  Prokaryotic or Eukaryotic cells.
 Only organisms of the domains Bacteria
and Archaea consist of prokaryotic cells –
cells without a membrane bound nucleus.
 Protists, fungi, animals and plants all
consist of eukaryotic cells – cell with a
membrane bound nucleus.

16. PLANT CELL ANIMAL CELL
CELL WALL CELL MEMBRANE
CHLOROPLAST NO CHLOROPLAST
BIG IN PLANTS SMALL IN ANIMALS
CAN PHOTOSYNTHESIZE CANNOT PHOTOSYNTHESIZE
MAKE THEIR FOOD DEPENDENT ON PLANTS IN CASES
OF FOOD

17. Chapter 6 p. 98 – 131

18.  Porous
 Varies in thickness
 Consist of pectin (elasticity), cellulose fibrils
held together with non-cellulose substances
(hardens the cell when mature) and lignin
(adds strength to cell especially in woody
plants)
 Cell wall is permeable and protects the inside
of the cell.
 Middle lamella (layer of adhesive substances) –
holds the cells together
 Plasmodesmata (pores) that connects the
cytoplasm of the connecting cells – selectively
permeable

20.  Consist of 2
phospholipid layers
and proteins in
between.
 The phospholipid
layers are part
hydrophillic and
part hydrophobic

21.  +/- 5µm, largest organelle in cell.
 Enclosed by a nucleomembrane
with nuclear pores. Function:
Protection and add to selective
permeability.
 Filled with nucleoplasma, a
nucleolus and chromatin. Function
of chromatin: carries genetic
material in the form of
chromosomes.
 Function of nucleolus: Produce r-
RNA

22.  Consist of 2 membranes: Outer –
and a highly convoluted inner
membrane- These folds are
called cristae – they increase the
surface area.
 Filled with matrix called stroma
that contains DNA and
ribosomes.
 Function: Produce energy in the
form of ATP by means of
cellular respiration

23.  Enclosed by a double
membrane
 Filled with stroma and
thylakoids filled with
chlorophyll arranged in
groups called grana.
 Ribosomes and starch grains
in stroma.
 Function: Photosynthesis

24.  Membranous sac
 Filled with cell sap.
 Causes turgor pressure in the
vacuole.
 Function: Stores various
substances, including waste.
 Helps with osmotic potential of
cell.

25.  Endoplasmic Reticulum – Transport
system in cell
 Ribosomes – Protein synthesis
 Golgi-apparatus – Make lysosomes and
acts as transport system.
 Lysosomes – Intracellular digestion.
 Plastids e.g.– Leucoplasts – Stores
starch
- Chromoplast – gives colour
to flowers and fruit.
* Centrioli – Mitosis in animal cells

26.  The cell membrane has the ability to
regulate transport molecules across
its structure.
 This function is essential to the cell’s
existence.
 The fluid mosaic model helps to
explain how membranes regulate the
cell’s molecular traffic.

27.  Hydrocarbons, carbon dioxide and
oxygen – non-polar
 So they can dissolve in the lipid bilayer of
the membrane.
 They can cross the membrane without
the aid of membrane proteins.
 Polar molecules like, water and glucose
move slowly across the membrane and
need the aid of proteins to get across
the membrane.

28.  Hydrophyllic substances can avoid
contact with the hydrophobic lipid bilayer
by passing through transport proteins that
span the membrane.
 Channel proteins – tunnel for polar
molecules to pass through membrane
 Aquaporins – channel proteins for the
transport of water

29.  Carrier protein: Hold onto solutes that
want to move across the membrane and
changes shape as it moves through the
membrane.
 Each carrier protein is specific to what it
transports.

30.  The microscope is an instrument
designed to observe objects too small to
be seen with the naked eye.
 The human eye cannot distinguish
objects much smaller than 0.1mm.
 The microscope act as an extension of
the eye, allowing one to see smaller
objects.

32.  STUDY HOW TO TAKE CARE OF THE
MICROSCOPE AND HOW TO MAKE A
MICROSCOPE SLIDE.