Cell structure

1. 1
Basic Structure of a Cell
copyright cmassengale

2. 2
Introduction to CellsIntroduction to Cells
Cells are the basic units of organisms
Cells can only be observed under
microscope
Basic types of cells:
Animal Cell Plant CellBacterial Cell
copyright cmassengale

3. 3
Number of Cells
Organisms may be:
• Unicellular –
composed of one cell
• Multicellular-
composed of many
cells that may organize
copyright cmassengale

4. 4
 Prokaryotes include bacteria & lack
a nucleus or membrane-bound
structures called organelles
Eukaryotes include most other cells
& have a nucleus and membrane-bound
organelles (plants, fungi, & animals)
Cells May be Prokaryotic or
Eukaryotic
copyright cmassengale

5. 5
Prokaryotes
Nucleoid region
contains the DNA
•Cell membrane &
cell wall
• Contain ribosomes
(no membrane) to
make proteins in
their cytoplasm
copyright cmassengale

6. 6
Eukaryotic Cell
Contain 3 basic cell
structures:
•Nucleus
•Cell Membrane
•Cytoplasm with
organelles
copyright cmassengale

7. 7
Two Main Types of
Eukaryotic Cells
Plant Cell
Animal Cell
copyright cmassengale

8. 8
OrganellesOrganelles
Very small size
Can only be observed under a
microscope
Have specific functions
Found throughout cytoplasm
copyright cmassengale

9. 9
Organelles Found in Cells
Examples of Organelles include:
Endoplasmic reticulum (rough & smooth) –
canals for movement
Golgi Bodies – wrap & export proteins
Nucleolus – makes ribosomes
Lysosomes – digests & gets rid of wastes
Ribosomes – makes proteins
copyright cmassengale

10. 10
Golgi Bodies
•Stacks of Stacks of flattened flattened
sacssacs
•Have a shipping side & Have a shipping side &
a receiving sidea receiving side
•Receive & Receive & modify modify
proteinsproteins made by ER made by ER
•Transport vesiclesTransport vesicles
with modified proteins with modified proteins
pinch off the endspinch off the ends
Transport
vesicle
copyright cmassengale

11. 11
Lysosome
•Contain digestive Contain digestive
enzymesenzymes
•Break down food and Break down food and
worn out cell parts for worn out cell parts for
cells cells
•Programmed for cell Programmed for cell
death (lyse & release death (lyse & release
enzymes to break down enzymes to break down
& recycle cell parts)& recycle cell parts)
copyright cmassengale

12. 12
Nucleolus
• Cell may have Cell may have 1 to 31 to 3
nucleolinucleoli
•Inside nucleusInside nucleus
•DisappearsDisappears when cell when cell
dividesdivides
•Makes ribosomesMakes ribosomes that that
make proteinsmake proteins
copyright cmassengale

13. 13
Smooth & Rough Endoplasmic
Reticulum
Smooth ER lacks
ribosomes &
makes proteins
USED In the cell
Rough ER has
ribosomes on its
surface & makes
proteins to
EXPORT
copyright cmassengale

14. 14
Rod shape
Site of Cellular
respiration
Cell PowerhouseCell Powerhouse
Mitochondrion
( mitochondria )
copyright cmassengale

15. 15
Active cells like
muscles have more
mitochondria
Burn sugars to
produce energy ATP
In Animal Cells:In Animal Cells:
Mitochondria
copyright cmassengale

16. 16
Lies immediately
against the cell wall
in plant cells
Made of protein and
phospholipids
Selectively permeable
Cell membrane
Surrounding the CellSurrounding the Cell
copyright cmassengale

17. 17
Living layer
Controls the
movement of
materials into and
out of the cell
Selectively
permeable
Cell membrane
Cell or Plasma MembraneCell or Plasma Membrane
copyright cmassengale

18. 18
Nonliving layer
Gives structure and
shape to plant and
bacterial cells
Cell wall
Cell WallCell Wall
copyright cmassengale

19. 19
Jelly-like substance
enclosed by cell
membrane
Provides a medium
for chemical
reactions to take
place
Cytoplasm
Cytoplasm of a Cell Cytoplasm of a Cell
copyright cmassengale

20. 20
Contains organelles
to carry out
specific jobs
Examples: chloroplast
& mitochondrion
Cytoplasm
More on CytoplasmMore on Cytoplasm
copyright cmassengale

21. 21
Controls the normal
activities of the cell
Contain the DNA
Bounded by a
nuclear membrane
Contains chromosomes
Control Organelle
Nucleus
copyright cmassengale

22. 22
Each cell has fixed

number of
chromosomes that
carry genes
Genes control cell
characteristics
Nucleus
More on the NucleusMore on the Nucleus
copyright cmassengale

23. 23
Contain the green
pigment chlorophyll
Traps sunlight to
make to make sugars
(food)
Process called
photosynthesis
Plant Cell OrganellesPlant Cell Organelles
Chloroplast
copyright cmassengale

24. 24
Dead layer
Large empty spaces
present between
cellulose fibers
Freely permeable
Cell wall
Plant CellPlant Cell
copyright cmassengale

25. 25
Plant CellPlant Cell
Made of cellulose
which forms very
thin fibers
Strong and rigid
Found in plant cells
Cell wall
copyright cmassengale

26. 26
Protect and support
the enclosed
substances
(protoplasm)
Resist entry of excess
water into the cell
Give shape to the cell
Cell wall
Plant CellPlant Cell
copyright cmassengale

27. 27
Have a large central
vacuole
Surrounded by tonoplast
Contains cell sap
Sugars, proteins, minerals,
wastes, & pigments
Plant Cell OrganellesPlant Cell Organelles
Vacuole
copyright cmassengale

28. 28
Different kinds of plant Different kinds of plant
cellscells
Onion Epidermal Cells
Root Hair Cell
root hair
Guard Cells
copyright cmassengale

29. 29
mitochondrion
nucleus
glycogen
granule
cell
membrane
cytoplasm
Animal cellAnimal cell
No cell wall or
chloroplast
Stores glycogen
in the cytoplasm
for food energy
vacuole
copyright cmassengale

30. 30
Animal Cell OrganellesAnimal Cell Organelles
•Near the nucleus
•Paired structures
•Help cell divide
copyright cmassengale

31. 31
Different kinds of animal Different kinds of animal
cellscells
white blood cell
red blood cell
cheek cells
sperm
nerve cell
muscle cell
Amoeba
Parameciumcopyright cmassengale

32. 32
Similarities between plant Similarities between plant
cells and animal cellscells and animal cells
Both have a cell membrane
surrounding the cytoplasm
Both have a nucleus
Both contain mitochondria
copyright cmassengale

33. 33
Differences between plant Differences between plant
cells and animal cellscells and animal cells
Animal cells Plant cells
Relatively
smaller in size
Irregular shape
No cell wall
Relatively larger
in size
Regular shape
Cell wall present
copyright cmassengale

34. 34
Animal cells Plant cells
Vacuole small or
absent
Glycogen as food
storage
Nucleus at the
center
Large central
vacuole
Starch as food
storage
Nucleus near cell
wall
Differences between Plant Differences between Plant
Cells and Animal CellsCells and Animal Cells
copyright cmassengale

35. 35
Compound MicroscopeCompound Microscope
•Instrument for
observing small
objects
•Magnify images
up to 2000X
their size
copyright cmassengale

36. 36
Different parts of Different parts of
a microscopea microscope
copyright cmassengale

37. 37
Eyepiece
Fine adjustment
Arm
Stage
Condenser
control knob
Base
Body tube
Coarse
adjustment
Iris diaphragm
Revolving
nosepiece
Objective
Clip
Condenser
Mirror
copyright cmassengale

38. 38
The cell is the Basic Unit The cell is the Basic Unit
of Lifeof Life
•Cell is the smallest unit of living organisms
•Unicellular organisms are made of one cell
only
•The cells of multicellular organisms are
specialized to perform different functions
–e.g. mesophyll cells for photosynthesis
and root hair cells for water absorption
copyright cmassengale

39. 39
Levels of organizationLevels of organization
•Cells are
grouped
together and
work as a
whole to
perform special
functions
copyright cmassengale

40. 40
TissueTissue
•A group of similar cells to
perform a particular function
–Animals : epithelial tissue,
muscular tissue
–Plants : vascular tissue,
mesophyll
copyright cmassengale

41. 41
OrganOrgan
•Different tissues group together
to carry out specialized functions
–Heart : consists of muscles,
nervous tissue and blood
vessels
–Leaf : consists of epidermis,
mesophyll and vascular tissue
copyright cmassengale

42. 42
Stoma
Air Space
Spongy Mesophyll
Cell
Chloroplast
The Structures of a Leaf
(Plant Organ)
Palisade
Mesophyll Cell
copyright cmassengale

43. 43
The Structures of a Heart
(Animal Organ)
copyright cmassengale

44. 44
SystemSystem
•Several organs and tissues work together
to carry out a particular set of
functions in a co-ordinated way
–Human : digestive, respiratory, excretory,
circulatory and reproductive systems
–Plant : root and shoot systems
copyright cmassengale

45. 45
Human Body SystemsHuman Body Systems
Examples of systems :
Digestive System
Respiratory System
Circulatory System
Nervous System
Reproductive System
copyright cmassengale

46. 46
Examples of a Human Body System
copyright cmassengale

47. 47
Examples of a Human Body System
The Respiratory System
copyright cmassengale

48. 48
Examples of a Human Body System
Circulatory System
copyright cmassengale

49. 49
Examples of a Human Body System
Nervous System
copyright cmassengale

50. 50
Levels of OrganizationLevels of Organization
CELLS (muscle cells,nerve cells)
TISSUES (muscle, epithelium)
ORGANS (heart, lungs,
stomach)
SYSTEMS (circulatory system)
ORGANISM (human)
copyright cmassengale

51. 51
It’s You!
copyright cmassengale