Download Chapter 3 The Basic Structure of a Cell - GMCbiology

Opening Assignment
THIS IS A MACHINE THAT REQUIRES SEVERAL PARTS TO DO ITS
JOB. THINK ABOUT ITS JOB THEN ANSWER THE FOLLOWING:
- ARE THERE ANY PARTS YOU CAN TAKE OUT AND IT STILL
FUNCTION?
- ARE THERE ANY PARTS THAT YOU ABSOLUTELY CANNOT
REMOVE WITHOUT CHANGING ITS FUNCTION?
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Basic Structure of a Cell
2
Discovery of the Cell
• Robert Hooke (1665) →
examined a slice of
cork under the
microscope, he saw
boxes that he called
cells
• Anton Van
Leeuwenhoek (1675) →
looked at pond water
and found small living
organisms –
“animalcules”
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Formation of the Cell Theory
• Matthias Schleiden → cells compose every part of
plants
• Theodor Schwann → cells compose every part of
animals
• Rudolph Virchow → cells come only from other
cells
Rudolph Virchow
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The Cell Theory
1. All living organisms are
composed of one or
more cells
2. In organisms, cells are
the basic units of
structure and function
3. Cells are produced only
from existing cells
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History & Discovery Questions
• What are some ways our knowledge has
advanced regarding cells, based on the
developments done by these & other
scientists? (think of some current research
being done and information in the news)
• Think about the part of the cell theory that
states cells are produced only from preexisting cells. What does this mean? What
does it make you think about?
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Review of Introduction to Cells
Cells are the basic units of organisms
Cells can only be observed under
microscope
Basic types of cells:
Animal Cell
Plant Cell
Bacterial Cell
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Number of Cells
Organisms may be:
• Unicellular –
composed of one cell
• Multicellularcomposed of many
cells that may
organize
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Cells May be Prokaryotic or
Eukaryotic
 Prokaryotes include bacteria & lack a
nucleus or membrane-bound structures
called organelles – small single-celled
Eukaryotes include most other cells &
have a nucleus and membrane-bound
organelles (plants, fungi, & animals) –
larger than prokaryotes and can be
either unicellular or multicellular
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Prokaryote & Eukaryote
Questions
• If Prokaryotes don’t have a nucleus does that
mean that they do not have any DNA?
• Eukaryotes have membrane-bound
organelles, which are specialized to perform
specific cellular tasks. What characteristic
of life does this best coincide with?
10
Prokaryotes
Nucleoid region
contains the DNA
•Cell membrane &
cell wall
• Contain ribosomes
(no membrane) to
make proteins in
their cytoplasm
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Two Main Types of
Eukaryotic Cells
Plant Cell
Animal Cell
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Organelles
Very small size
Can only be observed under a
microscope
Have specific functions
Found throughout cytoplasm
13
ORGANELLES & OTHER
STRUCTURES OF THE CELL
14
Nucleolus
Nucleolus
Make the
______________
15
Ribosomes
Ribosomes
Site of
_____________
(the production of proteins)
Located freely or more
often on the outer surface
of the rough endoplasmic
reticulum
16
Proteins
Protein
 End ___________ of
the cell
 Gives structure
/characteristics and
function to cells &
whole organisms.
17
Endoplasmic Reticulum
Endoplasmic
Reticulum
 Newly made proteins fold
& assemble into their
complete structure.
 The ER will serve as
____________________
of the proteins making
sure they have their
correct structure in order
to function
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Golgi Apparatus




Golgi
Apparatus
Also known as Golgi Body or
Golgi Complex
___________________(add
carbs chains if needed),
___________________, and
_______________ proteins
for export to final
destination
Transports lipids as well
Creates the lysosomes
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Lysosome
Lysosome
 Contain Digestive
___________________
(____________________
____________________)
 Break down food & worn
out cell parts for the cell
 All lysosomal enzymes
are acid hydrolases that
are active at pH of 5
which are rendered
inactive if released in the
cytoplasm which has a pH
of 7.2
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21
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Control Organelle
Nucleus
Controls the normal
activities of the cell
Bounded by a
nuclear membrane
Contains chromosomes
23
More on the Nucleus
Nucleus
Each cell has fixed
number of
chromosomes that
carry genes
Genes control cell
characteristics
24
Cytoplasm of a Cell
Cytoplasm
Jelly-like substance
enclosed by cell
membrane
Provides a medium
for chemical
reactions to take
place
25
More on Cytoplasm
Cytoplasm
Contains organelles
to carry out
specific jobs
Examples:
chloroplast &
mitochondrion
26
Surrounding the Cell
Cell membrane
Lies immediately
against the cell wall
in plant cells
Made of protein and
phospholipids
Selectively permeable
27
Cell or Plasma Membrane
Cell membrane
Living layer
Controls the
movement of
materials into and
out of the cell
Selectively
permeable
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Cell Powerhouse
Mitochondrion
( mitochondria )
Rod shape
Site of Cellular
respiration
29
In Animal Cells:
Mitochondria
Active cells like
muscles have more
mitochondria
Burn sugars to
produce energy ATP
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Plant Cell Organelles
Chloroplast
Contain the green
pigment chlorophyll
Traps sunlight to
make sugars (food)
Process called
photosynthesis
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Plant Cell
Cell wall
Dead layer
Large empty spaces
present between
cellulose fibers
Freely permeable
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Plant Cell
Cell wall
Made of cellulose
which forms very
thin fibers
Strong and rigid
Found in plant cells
33
Plant Cell
Cell wall
Protect and support
the enclosed
substances
(protoplasm)
Resist entry of
excess water into
the cell
Give shape to the cell
34
Plant Cell Organelles
Vacuole
Have a large central
vacuole
Surrounded by tonoplast
Contains cell sap
Sugars, proteins,
minerals, wastes, &
pigments
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Different kinds of plant
cells
Onion Epidermal Cells
Guard Cells
root hair
Root Hair Cell
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vacuole
cytoplasm
nucleus
mitochondrion
glycogen
granule
Animal cell
No cell wall or
chloroplast
Stores glycogen
in the
cytoplasm for
food energy
cell
membrane
37
Animal Cell Organelles
• Near the nucleus
• Paired structures
• Help cell divide
38
Different kinds of animal
cells
white blood cell
Amoeba
red blood cell
muscle cell
cheek cells
sperm
nerve cell
Paramecium
39
Similarities between plant
cells and animal cells
Both have a cell membrane
surrounding the cytoplasm
Both have a nucleus
Both contain mitochondria
40
Differences between plant
cells and animal cells
Animal cells
Plant cells
Relatively
smaller in size
Relatively
larger in size
Irregular shape
Regular shape
No cell wall
Cell wall present
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Differences between Plant
Cells and Animal Cells
Animal cells
Plant cells
Vacuole small or
absent
Large central
vacuole
Glycogen as food
storage
Starch as food
storage
Nucleus at the
center
Nucleus near cell
wall
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Microscopes
43
Compound Microscope
• Instrument for
observing small
objects
• Magnify images
up to 2000X
their size
44
Different parts of a
compound microscope
45
Revolving
nosepiece
Eyepiece
Clip
Body tube
Coarse
adjustment
Fine adjustment
Condenser
Arm
Iris diaphragm
Stage
Objective
Mirror
Condenser
control knob
Base
46
Electron Microscope
• Transmission EM (TEM)
– Uses a beam of
electrons to produce an
enlarged image of very
thinly sliced specimen
on screen or
photographic plate
– Image focused by
magnetic lenses
– 200,000X magnification
– Cannot be used to view
living specimens
47
• Scanning EM (SEM)
– 3D image
– Specimens not sliced
for viewing
– Surface sprayed with
fine metal coating
– Also uses electron
beam and fluorescent
screen or photographic
plates
– 100,000X magnification
– Cannot be used to view
living specimens
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The cell is the Basic Unit
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
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Levels of organization
• Cells are
grouped
together and
work as a
whole to
perform special
functions
50
Tissue
• A group of similar cells to
perform a particular function
– Animals : epithelial tissue,
muscular tissue
– Plants : vascular tissue,
mesophyll
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Organ
• 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
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The Structures of a Leaf
(Plant Organ)
Chloroplast
Palisade
Mesophyll Cell
Spongy Mesophyll
Cell
Air Space
Stoma
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The Structures of a Heart
(Animal Organ)
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System
• 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
55
Human Body Systems
Examples of systems :
 Digestive System
 Respiratory System
 Circulatory System
 Nervous System
 Reproductive System
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Examples of a Human Body System
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Examples of a Human Body System
The Respiratory System
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Examples of a Human Body System
Circulatory System
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Examples of a Human Body System
Nervous System
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Levels of Organization
CELLS
(muscle cells,nerve cells)
TISSUES (muscle, epithelium)
ORGANS (heart, lungs,
stomach)
SYSTEMS (circulatory system)
ORGANISM (human)
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It’s You!
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