Life science Grade 10

1. • Name: Gugu Msana
• Student number: 201181428
• Module : Professional studies 3a
• Course: B. Education
• List of sources provided in the last slide

2. TOPIC
CELLS: THE BASIC UNIT OF
LIFE

3. what is a cell ?
Cell is the basic unit of life.
All organisms are composed of cell
Some organisms are unicellular .eg: bacteria
And while some are multicellular . eg: human
Cell is the fundamental structural and
functional unit of all living organisms.

4. PLANT CELL

5. ANIMAL CELL

6. History of cell study
Robert hooke-1665
Coined the word “cell”.
Looked at cork cells.
Robert brown-1831
Discovered the “nucleus”.
Theodor Schwann- 1838
Cells are unit of biological structures.
Mattias Schleiden-1850
Cell are the fundamental basis of life.
Virchow-1858
All cells come from cells.

7. Theodor Schwann Mattias Schleiden
Rudolf Virchow Robert Brown

8. 1. Every organisms is made up of at least one cell.
2. Cells are the basic structural and functional
unit of multicellular organisms.
3. All cells arise from preexisting cells.

10. CELL WALL
1. a non living rigid structure .
2. Forms an outer covering for
plasama membrane.
function:
1) Determining Cell Shape.
2) Strength.
3) Controlling Turgor Pressure.
4) Passage of Substances.
5) Protection.
Primary wall:
• The wall which help to grow in
youger plant
• diminishes as cell get mature.

11. Endomembrane system
contains only those
organelles whose
functions are
coordinated.
It consists of:
 Endoplasmic
reticulum(ER)
 Golgi complex
 lysosomes
 Vacuoles

12. Discovered by porter and thompson.
 ER are a network of tiny tubular structures
scattered in the cytoplasm.
 consists of 30-40% of endomembrane system
 ER divides into 2 compartments.
1. luminal(inside ER)
2. extra luminal(cytoplasm)
FUNCTIONS:
1. Mechanical support
2. Conduction of information
3. Intercellular transport
4. Localization of enzyme
5. Large surface area.

13. Endoplasmic reticulum
cont….
• Dicovered by porter and
thompson.
• It is a complex membrane
lined network of flattened
sac, tubles etc..
• runs through out
cytoplasm of eukaryotic
cells.
• Cosist of 30-40% of total
endomembrane system.
• Divides the intercellular
space into components.
Luminal and
extraluminal

14. • Has two main types:
Smooth endoplasmic reticulum and
rough endoplasmic reticulum.
Functions:
1. Mechanical support
2. Conduction of information
3. Intercellular transport
4. Localisation of enzymes.
5. Large surface area.
Function of RER:
1. Protein for transport
2. Protein processing
Function of SER:
1. Storage.
2. Glycogenolysis.

15. Golgi apparatus
• Is a cytoplasmic organelle osf
smooth membrane sac.
• Dicovered by camillo golgi,
• Found in eukaryotic cells (except
mammalian erythrocytes)
• Occur between nucleus and
exposed cell surface.
• Surrounded by zone of cytoplasm
which is devioded of ribosomes,
mitochondria, etc...
Functions:
Package materials. And important
for formation of glycoprotein.

16. Lysosomes and vacuole
lysosomes
• Membrane bound vesicular structure
• Formed by packaging of golgi appartus.
• Very rich in hydrolytic enzymes.
• Enzymes are capable for digesting
carbohydrate, protein, lipid, mucleic acid.
• Polpularly called as “suicide bags”,
Vacuoles:
• Membrane bound space found In
cytoplasm.
• Bounded by single membrane called
tonoplast,
• In amoeba, called contractile vacuole
and in proista food vacuole

17. mitochondria• These are double –membrane bound, sausage –
shaped semi-autonomous organelles.
• The electron micrograph shows that the
boundarymembranes are separated by a fluid
filled spacecalled outer compartment.
• The outer membrane is smooth but the inner
smooth projects in the form of many folds
calledcristae into the matrix.
• The matrix is rich in enzymes, a circular DNA
• molecule and many small ribosomes.
• The inner membrane and the cristae bear a number
of particles, which have a spherical head– piece
(F1 subunit) and a stalk (F0 subunit) that is
embedded in the lipid of the membrane.
• The F0 – F1 combination functions as ATP
synthetase.
• The main function of mitochondria is aerobic
respiration and ATP synthesis

18. …Plastids…Found in plants and euglenoids.
They are large
They contain pigments, imparting colors and storage products.
Plastids can be classified into:
*CHLOROPLAST *CHROMOPLAST *LEUCOPLAST
•Contains chlorophyll and
carotenoid pigments.
•Found mainly in mesophyll of
leaves .
•These are lens shaped, oval
shaped, spherical, discoid or
even ribbon-like organelles.
•Contains fat soluble
carotenoid pigments like
carotene, xanthrophylls
and others are present.
•Found in yellow, orange,
red.
•Colorless plastids
•Various shapes and sizes
with stored nutrients
•LEUCOPLAST can be divided
into 3:-
1.Amyloplasts – store
carbohydrates
2.Elaioplasts – store oils
and fats
3. Aleuroplasts – store
proteins.

19. plastids• Plastids are double – membrane bound organelles of
different shapes, that are found only
• in plant cells and contain pigments and storage
products.
• These are three types of plastids, depending on their
colour and functions.
• Chromoplasts
• These are the coloured plastids containing mainly the
yellow, red and orange pigments (carotene and
xanthophylls).
• (iii) Chloroplasts
• These are the green plastids containing mainly
chlorophylls and very little of carotene and
xanthophylls.
• Chloroplasts may be lens – shaped, oval,spherical,
discoid, ribbon-like or cup –shaped
• Each chloroplast has a double membrane
• covering, enclosing the colourless matrix
• called stroma.

20. Reference list
• Robayda, A. (2013). cell the unit of life. Available:
http://www.slideshare.net/AishaRobayda/cell-the-unit-of-life-1?qid=12bc18e8-e13c-
4232-9b02-cf1652411b05&v=qf1&b=&from_search=3 (Accessed 07 march 2014)
• ittah,E. (2013). Cell- The basic Structure of life.
Available: http://www.slideshare.net/ericittah/eric-ittah-canada-eric-
ittah?qid=12bc18e8-e13c-4232-9b02-cf1652411b05&v=qf1&b=&from_search=5
(accessed 07 march 2014)
• Baiju, V. (2011). Cell The unit of life. Available:
http://www.slideshare.net/VigneshBaiju/cell-the-unit-of-life-
10230437?qid=12bc18e8-e13c-4232-9b02-
cf1652411b05&v=qf1&b=&from_search=8 (accessed 07 march 2014)