Upload
alexander-byrd
View
218
Download
0
Tags:
Embed Size (px)
Citation preview
HISTORY OF CELL
• STARTED WITH DISCOVERING THE FIRST MICROSCOPE
• Hans and Zacharias Janssen • Dutch lens grinders, father and son • produced first compound microscope
(2 lenses)
3
HISTORY OF CELL• Robert Hooke (1665)• English scientist • looked at a thin slice of cork (oak cork)
through a compound microscope • observed tiny, hollow, room like structures • called these structures 'cells' because they
reminded him of the rooms that monks lived in • only saw the outer walls (cell walls) because
cork cells are not alive
4
HISTORY OF CELL
• Anton van Leeuwenhoek (around the same time as Hooke 1680?)
• Dutch fabric merchant and amateur scientist • looked at blood, rainwater, scrapings from
teeth through a simple microscope (1 lens) • observed living cells; called some
'animalcules' • some of the small 'animalcules' are now
called bacteria
5
HISTORY OF CELL• Matthias Schleiden (1838)• German botanist • viewed plant parts under a microscope • discovered that plant parts are made of cells
• Theodor Schwann (1839) • German zoologist • viewed animal parts under a microscope • discovered that animal parts are made of
cells
6
HISTORY OF CELL• Rudolph Virchow (1855)• German physician • stated that all living cells come only from
other living cells • Credited with completing the CELL THEORY
7
9
Introduction to CellsIntroduction to CellsCells are the basic units of organismsCells can only be observed under
microscopeBasic types of cells:
Animal Cell Plant CellBacterial
Cell
10
Number of CellsOrganisms may be:• Unicellular – composed of one cell• Multicellular- composed of many cells that may organize
11
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
12
ProkaryotesNucleoid region contains the DNA
•Cell membrane & cell wall
• Contain ribosomes (no membrane) to make proteins in their cytoplasm
13
Eukaryotic Cell
Contain 3 basic cell structures:
•Nucleus•Cell Membrane•Cytoplasm with
organelles
15
OrganelleOrganelless
Very small size
Can only be observed under a microscope
Have specific functions
Found throughout cytoplasm
16
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
17
Golgi Bodies• Stacks of Stacks of flattened flattened
sacssacs• Have a shipping side Have a shipping side
& a receiving side& a receiving side• Receive & Receive & modify modify
proteinsproteins made by ER made by ER• Transport vesiclesTransport vesicles
with modified with modified proteins pinch off proteins pinch off the endsthe ends
Transport
vesicle
18
Lysosome• Contain digestive Contain digestive
enzymesenzymes• Break down food and Break down food and
worn out cell parts worn out cell parts for cells for cells
• Programmed for cell Programmed for cell death (lyse & release death (lyse & release enzymes to break enzymes to break down & recycle cell down & recycle cell parts)parts)
19
Nucleolus• Cell may have Cell may have 1 1
to 3to 3 nucleoli nucleoli• Inside nucleusInside nucleus• DisappearsDisappears when when
cell dividescell divides• Makes ribosomesMakes ribosomes
that make that make proteinsproteins
20
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
Structure of Plant Cells• Smooth Endoplasmic
Reticulum- Portion of the endoplasmic reticulum that has no ribosomes and thus appears smooth
• Produces steroids and other lipids
• Also called Smooth ER
Structure of Plant Cells•Rough Endoplasmic
Reticulum- Major portion of the endoplasmic reticulum that has ribosomes and thus appears rough
•Produces proteins•Also called Rough ER
23
Rod shapeSite of Cellular respiration
Cell PowerhouseCell Powerhouse
Mitochondrion( mitochondria )
24
Active cells like muscles have more mitochondriaBurn sugars to produce energy ATP
In Animal Cells:In Animal Cells:
Mitochondria
25
Lies immediately against the cell wall in plant cells
Made of protein and phospholipids
Selectively permeable
Cell membrane
Surrounding the Surrounding the CellCell
26
Controls the movement of materials into and out of the cell
Selectively permeable
Cell membrane
Cell or Plasma Cell or Plasma MembraneMembrane
27
Jelly-like substance enclosed by cell membrane
Provides a medium for chemical reactions to take place
Cytoplasm
Cytoplasm of a Cytoplasm of a Cell Cell
28
Contains organelles to carry out specific jobs
Examples: chloroplast & mitochondrion
Cytoplasm
More on More on CytoplasmCytoplasm
29
Controls the normal activities of the cell
Bounded by a nuclear membrane
Contains chromosomes
Control Organelle
Nucleus
30
Each cell has fixed number of chromosomes that carry genes
Genes control cell characteristics
Nucleus
More on the More on the NucleusNucleus
31
Contain the green pigment chlorophyll
Traps sunlight to make to make sugars (food)
Process called photosynthesis
Plant Cell OrganellesPlant Cell Organelles
Chloroplast
33
Plant CellPlant Cell
Made of cellulose which forms very thin fibers
Strong and rigidFound in plant cells
Cell wall
34
Protect and support the enclosed substances
Resist entry of excess water into the cell
Give shape to the cell
Cell wall
Plant CellPlant Cell
35
Have a large central vacuole
Surrounded by tonoplast
Contains cell sapSugars, proteins,
minerals, wastes, & pigments
Plant Cell OrganellesPlant Cell Organelles
Vacuole
36
Different kinds of Different kinds of plant cellsplant cells
Onion Epidermal Cells
Root Hair Cell
root hair
Guard Cells
37
mitochondrion
nucleus
glycogen granule
cell membrane
cytoplasm Animal cellAnimal cell
No cell wall or chloroplastStores glycogen in the cytoplasm for food energy
vacuole
38
Animal Cell OrganellesAnimal Cell Organelles
•Near the nucleus•Paired structures•Help cell divide
39
Different kinds of Different kinds of animal cellsanimal cells
white blood cell
red blood cell
cheek cells
sperm
nerve cell
muscle cell
Amoeba
Paramecium
40
Similarities between Similarities between plant cells and animal plant cells and animal
cellscellsBoth have a cell membrane surrounding the cytoplasm
Both have a nucleus
Both contain mitochondria
41
Differences between Differences between plant cells and animal plant cells and animal
cellscellsAnimal cells Plant cells
Relatively smaller in
sizeIrregular shape
No cell wall
Relatively larger in size
Regular shapeCell wall present
42
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
43
The cell is the Basic The cell is the Basic Unit of LifeUnit of 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
44
Levels of organizationLevels of organization
• Cells are grouped together and work as a whole to perform special functions
45
TissueTissue
•A group of similar cells to perform a particular function–Animals : epithelial tissue, muscular tissue
–Plants : vascular tissue, mesophyll
46
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
47
Stoma
Air Space
Spongy Mesophyll Cell
Chloroplast
The Structures of a Leaf (Plant Organ)
Palisade Mesophyll Cell
49
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
50
Human Body SystemsHuman Body Systems Examples of systems : Digestive System Respiratory System Circulatory System Nervous System Reproductive System
55
Levels of OrganizationLevels of Organization
CELLS (muscle cells,nerve cells)TISSUES (muscle, epithelium)ORGANS (heart, lungs, stomach)
SYSTEMS (circulatory system)ORGANISM (human)