Cell Structure and Functions ppt presentation for Class 9 Students prepared by Susanta Kumar Panda, Sambalpur

1. Our School

3. Presents……

7. Definition of Cell…
A cell is the
smallest unit
that is capable
of performing
life functions.

8. The Cell Theory…

9. Examples of Cells
Amoeba Proteus
Plant Stem
Red Blood Cell
Nerve Cell
Bacteria

10. The Two Major Categories of
Cells….
The countless cells on earth fall into two categories:

12. PROKARYOTIC
 They are the simplest form of life.
 No nucleus.
 Do not have structures surrounded
by membranes (organelles)
 Few internal structures
 They are unicellular_(One-celled organisms).
 Example: Bacteria

13. ribosomes
cell wall
plasma membrane
food granule
prokaryotic
flagellum
cytoplasm
nucleoid (DNA)

14.  are the most complex form of life.
 They have nucleus
 Contain organelles surrounded by membranes
 They are multicellular organisms (composed of
many cells).
 Most living organisms
 Examples: animals and plants.
Eukaryotic

15. EUKARYOTIC
Plant Animal

16. Prokaryotes & Eukaryotes…
 Similarities & differences
 Both surrounded by plasma membrane,
but very different
 Prokaryotes – Archaebacteria and
Eubacteria
 Eukaryotes – everything else

18. “Typical” Plant Cell

20. Difference Between Plant & Animal Cells…
Plants have
Cell wall – provides strength & rigidity
Have chloroplasts, photosynthetic
Animals have
Other organelle not found in plants (lysosomes
formed from Golgi)
Centrioles, important in cell division

23.  All living cells (eukaryotes and
prokaryotes) have cell membranes
 Made mainly of phospholipids and proteins
▪ Animal cell membranes contain cholesterol
 Functions:
▪ Separate the cell from the external environment
▪ Controls passage in and out of cell

24.  Outer membrane of
cell that controls
movement in and out
of the cell
 Double layer

25. Membrane Structure

26. Cell Wall
Rigid structure outside cell
membrane
• Found in plants, fungi, bacteria,
some protists (not animals)
• Made of cellulose (plants),
chitin (fungi) or other material
(bacteria)
• Supports and protects cell

27. Inside the Cell

28. ORGANELLES
Cell Parts
CELL STRUCTURE AND FUNCTION

30. nuclear
pores
nuclear
pore
nuclear envelope
nucleolus
histone protein
chromosome
DNANucleus
 Function
protects DNA
 Structure
 nuclear envelope
 double membrane
 membrane fused in spots to create pores
 allows large macromolecules to pass through
What kind of
molecules need to
pass through?

31.  Function
 ribosome production
▪ build ribosome subunits from rRNA & proteins
▪ exit through nuclear pores to cytoplasm &
combine to form functional ribosomes
small
subunit
large subunit
ribosome
rRNA &
proteins
nucleolus

32. small
subunit
large
subunitRibosomes
 Function
 protein production
 Structure
 rRNA & protein
 2 subunits combine 0.08mm
Ribosomes
Rough
ER
Smooth
ER

33. membrane proteins
Types of Ribosomes
 Free ribosomes
◦ suspended in cytosol
◦ synthesize proteins that function
in cytosol
 Bound ribosomes
◦ attached to endoplasmic reticulum
◦ synthesize proteins
for export or
for membranes

34.  Function
• processes proteins
• manufactures membranes
• synthesis & hydrolysis of many compounds
 Structure
• membrane connected to nuclear envelope &
extends throughout cell

35. Types of ER
 Rough ER (RER) –
 Has ribosomes attached
 Site of protein synthesis
 Smooth ER (SER)
 Complex molecules built here
 Continuous with RER

36. Membrane production
Many metabolic processes
• synthesis
 synthesize lipids
 oils, phospholipids, steroids & sex hormones
• hydrolysis
 hydrolyze glycogen into glucose
 in liver
 detoxify drugs & poisons
 in liver
 ex. alcohol & barbiturates

37. Produce proteins for export out of cell
• protein secreting cells
• packaged into transport vesicles for export

38. Golgi Apparatus
 Function
 finishes, sorts, tags & ships cell products
 ships products in vesicles
 membrane sacs
 Structure
 Stack of flattened membranes
 “pita bread” like
transport vesicles
secretory
vesicles

39. Golgi Apparatus

40. Vesicles Transport…
 ER contents pinch off into vesicles - membrane-
bound sacs that store and transport substances in cells
vesicle
budding
from rough
ER
fusion
of vesicle
with Golgi
apparatus
migrating
transport
vesicle
protein
ribosome

41.  The movement of
macromolecules such as
proteins or
polysaccharides into or
out of the cell is called
bulk transport. There are
two types of bulk
transport, exocytosis and
endocytosis, and both
require the expenditure of
energy (ATP).

42.  Produces energy through
chemical reactions – breaking
down fats & carbohydrates
 Controls level of water and other
materials in cell
 Recycles and decomposes
proteins, fats, and carbohydrates

43. Cytoplasm
 Cytosol (cytoplasm)
 Cellular fluid surrounding organelles
 Site of many cellular reactions
 Found between cell membrane and nucleus

44. Lysosomes
 Lysosomes – special vesicles that store and transport
powerful digestive enzymes and other reactive
substances within a cell
 Double membrane protects cell from being digested
 Break down
Food particles
Unneeded proteins, carbohydrates, etc..
Disease-causing microorganisms

45. Vacuoles
 Large membranous storage sacs found
mainly in plants.
 Stores water, nutrients, waste products and
pigments
○ Give certain plants bright colors (beets,
carrots, flowers)

46. CILIA AND FLAGELLA…
 Hairlike organelles that
extend from the
surface of the cell
 Assist in movement
 Cilia – short and
present in large
numbers
 Flagella – long and
less numerous

47. Chromosomes…
 In nucleus
 Made of DNA
 Contain instructions
for traits &
characteristics

48. Chloroplast
 Usually found in plant
cells
 Contains green
chlorophyll
 Where photosynthesis
takes place

49. 21/07/2014

50. video B.avi

51. 21/07/2014
Any Questions!!

52. Thanks ...
ForgivingYourValuableTime…