Post on 06-May-2015
1
Basic Structure of a Cell
copyright cmassengale
2
Introduction to CellsIntroduction to CellsCells are the basic units of organismsCells can only be observed under
microscopeBasic types of cells:
Animal Cell Plant CellBacterial
Cellcopyright cmassengale
3
Number of CellsOrganisms may be:• Unicellular – composed of one cell• Multicellular- composed of many cells that may organize
copyright cmassengale
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
ProkaryotesNucleoid region contains the DNA
•Cell membrane & cell wall
• Contain ribosomes (no membrane) to make proteins in their cytoplasm
copyright cmassengale
6
Eukaryotic Cell
Contain 3 basic cell structures:
•Nucleus•Cell Membrane•Cytoplasm with
organelles
copyright cmassengale
7
Two Main Types of Eukaryotic Cells
Plant Cell
Animal Cell
copyright cmassengale
8
OrganelleOrganelless
Very small size
Can only be observed under a microscope
Have specific functions
Found throughout cytoplasm
copyright cmassengale
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 proteinscopyright cmassengale
10
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
vesiclecopyright cmassengale
11
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)
copyright cmassengale
12
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
copyright cmassengale
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
Rod shapeSite of Cellular respiration
Cell PowerhouseCell Powerhouse
Mitochondrion( mitochondria )
copyright cmassengale
15
Active cells like muscles have more mitochondriaBurn sugars to produce energy ATP
In Animal Cells:In Animal Cells:
Mitochondria
copyright cmassengale
16
Lies immediately against the cell wall in plant cells
Made of protein and phospholipids
Selectively permeable
Cell membrane
Surrounding the Surrounding the CellCell
copyright cmassengale
17
Living layerControls the movement of materials into and out of the cell
Selectively permeable
Cell membrane
Cell or Plasma Cell or Plasma MembraneMembrane
copyright cmassengale
18
Nonliving layerGives structure and shape to plant and bacterial cells
Cell wall
Cell WallCell Wall
copyright cmassengale
19
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
copyright cmassengale
20
Contains organelles to carry out specific jobs
Examples: chloroplast & mitochondrion
Cytoplasm
More on More on CytoplasmCytoplasm
copyright cmassengale
21
Controls the normal activities of the cell
Contain the DNABounded by a nuclear membrane
Contains chromosomes
Control Organelle
Nucleus
copyright cmassengale
22
Each cell has fixed number of chromosomes that carry genes
Genes control cell characteristics
Nucleus
More on the More on the NucleusNucleus
copyright cmassengale
23
Contain the green pigment chlorophyll
Traps sunlight to make to make sugars (food)
Process called photosynthesis
Plant Cell OrganellesPlant Cell Organelles
Chloropla
st
copyright cmassengale
24
Dead layerLarge empty spaces present between cellulose fibers
Freely permeable
Cell wall
Plant CellPlant Cell
copyright cmassengale
25
Plant CellPlant Cell
Made of cellulose which forms very thin fibers
Strong and rigidFound in plant cells
Cell wall
copyright cmassengale
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
Have a large central vacuole
Surrounded by tonoplast
Contains cell sapSugars, proteins,
minerals, wastes, & pigments
Plant Cell OrganellesPlant Cell Organelles
Vacuole
copyright cmassengale
28
Different kinds of Different kinds of plant cellsplant cells
Onion Epidermal Cells
Root Hair Cell
root hair
Guard Cells
copyright cmassengale
29
mitochondrion
nucleus
glycogen granule
cell membrane
cytoplasm Animal cellAnimal cell
No cell wall or chloroplastStores glycogen in the cytoplasm for food energy
vacuole
copyright cmassengale
30
Animal Cell OrganellesAnimal Cell Organelles
•Near the nucleus•Paired structures•Help cell divide
copyright cmassengale
31
Different kinds of Different kinds of animal cellsanimal cells
white blood cell
red blood cell
cheek cells
sperm
nerve cell
muscle cell
Amoeba
Paramecium
copyright cmassengale
32
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
copyright cmassengale
33
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
copyright cmassengale
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
Compound MicroscopeCompound Microscope
• Instrument for observing small objects
•Magnify images up to 2000X their size
copyright cmassengale
36
Different parts of Different parts of a microscopea microscope
copyright cmassengale
37
Eyepiece
Fine adjustmentArm
Stage
Condenser control knob
Base
Body tubeCoarse adjustment
Iris diaphragm
Revolving nosepiece
Objective
ClipCondenser
Mirror
copyright cmassengale
38
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
copyright cmassengale
39
Levels of organizationLevels of organization
• Cells are grouped together and work as a whole to perform special functions
copyright cmassengale
40
TissueTissue
•A group of similar cells to perform a particular function–Animals : epithelial tissue, muscular tissue
–Plants : vascular tissue, mesophyll
copyright cmassengale
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
Stoma
Air Space
Spongy Mesophyll Cell
Chloroplast
The Structures of a Leaf (Plant Organ)
Palisade Mesophyll Cell
copyright cmassengale
43
The Structures of a Heart (Animal Organ)
copyright cmassengale
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
Human Body SystemsHuman Body Systems Examples of systems : Digestive System Respiratory System Circulatory System Nervous System Reproductive System
copyright cmassengale
46
Examples of a Human Body System
copyright cmassengale
47
Examples of a Human Body System
The Respiratory System
copyright cmassengale
48
Examples of a Human Body System
Circulatory System
copyright cmassengale
49
Examples of a Human Body System
Nervous System
copyright cmassengale
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
It’s You!
copyright cmassengale