Download 04_Lecture_Presentation Cell I

Chapter 7
A Tour of the Cell
PowerPoint® Lecture Presentations for
Biology
Eighth Edition
Neil Campbell and Jane Reece
Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
History of the Cell
•Robert Hooke In 1665
Hooke published
Micrographia, a book
describing his microscopic
and telescopic
observations, and some
original work in biology.
Hooke coined the term cell
for describing the
resemblance of plant cells
to monk’s cells . He was
looking at cork
Anton Van Leeuwenhoek
• Leeuwenhoek
discovered bacteria,
free-living and
parasitic microscopic
protists, sperm cells,
blood cells,
microscopic
nematodes and
rotifers.
• animalcules
Schleiden and Schwann
The Cell theory
1. All living things are composed of one or more
cells
2. Cells are the basic building unit of life
3. New cells come from existing cells
What is the study of cells ?
10 m
1m
Human height
Length of some
nerve and
muscle cells
0.1 m
Chicken egg
1 cm
Unaided eye
Frog egg
100 µm
Most plant and
animal cells
10 µm
Nucleus
Most bacteria
1 µm
100 nm
10 nm
Mitochondrion
Smallest bacteria
Viruses
Ribosomes
Proteins
Lipids
1 nm
Small molecules
0.1 nm
Atoms
Electron microscope
1 mm
Light microscope
Fig. 6-2
Cell are not alike
• 1. size Eukaryotic cells 10.0 um – 100 um
Bacteria – 1.0 um -10.0 um
2. shape cuboidal – plant
spherical - animal
Eukaryotic cells have internal membranes that
compartmentalize their functions
• Only organisms of the domains Bacteria and
Archaea consist of prokaryotic cells
• Protists, fungi, animals, and plants all consist of
eukaryotic cells
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• Prokaryotic cells are characterized by having
– Monerans = Bacteria
– No nucleus
– No membrane-bound organelles
– Only ribosomes
– Large surface area to volume ratio ( class lab
activity)
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Fig. 6-6
Ribosomes
Plasma membrane
DNA
Cell wall
0.5 µm
(a) bacterium
(b) A thin section
through the
bacterium
Bacillus
coagulans (TEM)
A Panoramic View of the Eukaryotic Cell
• Eukaryotic cells have less surface area to
volume
• A eukaryotic cell has internal membranes that
help move around this large volume
• Plant and animal cells have most of the same
organelles
BioFlix: Tour Of An Animal Cell
BioFlix: Tour Of A Plant Cell
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 6-9a
Nuclear
envelope
ENDOPLASMIC RETICULUM (ER)
Flagellum
Rough ER
NUCLEUS
Nucleolus
Smooth ER
Chromatin
Centrosome
Plasma
membrane
CYTOSKELETON:
Microfilaments
Intermediate
filaments
Microtubules
Ribosomes
Microvilli
Golgi
apparatus
Peroxisome
Mitochondrion
Lysosome
Fig. 6-9b
NUCLEUS
Nuclear envelope
Nucleolus
Chromatin
Rough endoplasmic
reticulum
Smooth endoplasmic
reticulum
Ribosomes
Central vacuole
Golgi
apparatus
Microfilaments
Intermediate
filaments
Microtubules
Mitochondrion
Peroxisome
Chloroplast
Plasma
membrane
Cell wall
Plasmodesmata
Wall of adjacent cell
CYTOSKELETON
Plant cells and animal cells differ
•
Only Plants cells have ?
Cell wall, vacuoles, plastids
•
Only Animal cells have ?
Centrioles, lysosomes, cilia
and flagella
Cell membrane
•Also called the plasma
membrane
•Bilipid layer and proteins
•Phospholipid = bilipid
•Gives shape and flexibility
•Selectively permeablehas control over what can
cross, lipids that are
hydrophobic pass easily
Cytoplasm
• The area between the nucleus and membrane
• Contains cytosol; water, salts and organic
compounds
• Cytoplasmic streaming is a circular flow of
cytoplasm within cells
• This streaming speeds distribution of materials
within the cell
Video: Cytoplasmic Streaming
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Organelles
• Little organs with special functions
Ribosomes: Protein Factories
• Ribosomes
• Numerous
• Spherical
• Free floating or attached to the ER
(next slide)
• No membranes
• Ribosomes carry out protein synthesis
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 6-11
Cytosol
Endoplasmic reticulum (ER)
Free ribosomes
Bound ribosomes
Large
subunit
0.5 µm
TEM showing ER and ribosomes
Small
subunit
Diagram of a ribosome
The Endoplasmic Reticulum: Biosynthetic Factory
• The endoplasmic reticulum (ER)
• Membranes ( 50% of cell )
• Sacs and tunnels
• Transports materials
• two regions of ER:
– Smooth ER, lacks ribosomes, makes lipids
– Rough ER, with ribosomes …protein
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Fig. 6-12
Smooth ER
Rough ER
ER lumen
Cisternae
Ribosomes
Transport vesicle
Smooth ER
Nuclear
envelope
Transitional ER
Rough ER
200 nm
The Golgi Apparatus: Shipping and
Receiving Center
• The Golgi apparatus
• flattened membranous sacs
– Sorts and packages materials into transport
vesicles
– Modifies products of the ER
– Secretes proteins
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 6-13
cis face
(“receiving” side of
Golgi apparatus)
0.1 µm
Cisternae
trans face
(“shipping” side of
Golgi apparatus)
TEM of Golgi apparatus
Mitochondria
• Many membranes that make infolds called
cristae
• Respiration center
• Glucose + 02  C02 + H20 + energy (ATP)
abnormal mitochondria cause extreme fatigue
and weakness in legs, trouble breathing and
a host of other problems
Fig. 6-17
Intermembrane space
Outer
membrane
Free
ribosomes
in the
mitochondrial
matrix
Inner
membrane
Cristae
Matrix
0.1 µm
Lysosomes: Digestive Compartments
lysosome
• Small and spherical
• sac of hydrolytic enzymes that can digest
macromolecules and old cells
• acidic
Animation: Lysosome Formation
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Fig. 6-14a
Nucleus
1 µm
Lysosome
Lysosome
Digestive
enzymes
Plasma
membrane
Digestion
Food vacuole
(a) Phagocytosis
Concept 6.6: The cytoskeleton is a network of fibers
that organizes structures and activities in the cell
• The cytoskeleton is a network of fibers
extending throughout the cytoplasm
• It organizes the cell’s structures and activities,
2 types…
– Microtubules- large, hollow, help move
organelles, chromosomes and cilia
– Microfilaments- two strands, give the
membrane shape and help with cleavage
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Fig. 6-20
Microtubule
0.25 µm
Microfilaments
Cilia and Flagella
• Microtubules control the beating of cilia and
flagella,
• Both locomotor appendages of some cells
• Cilia short, row ex- trachea lining sweeps
mucus
• Flagella longer, moves like a snake, ex -sperm
Video: Chlamydomonas
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Video: Paramecium Cilia
Cilia and flagella
The Nucleus: Information Central
• The nucleus contains most of the cell’s genes
• Directs the cells activities
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• The nucleolus is located within the nucleus
and is the site of ribosomal synthesis
• In the nucleus, DNA and proteins form genetic
material called chromatin
Chromatin fine strands of DNA and protein
nuclear membrane – envelope, separates
the nucleus from the cytoplasm, double
membrane
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Centrioles
• Centrioles - microtubules arranged in a
centrosome area
• microtubules grow out from a centrosome
• Cell division
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Fig. 6-22
Centrosome
Microtubule
Centrioles
0.25 µm
Longitudinal section Microtubules Cross section
of one centriole
of the other centriole
Cell Walls of Plants
• The cell wall distinguishes plant cells from
animal cells
•
(Prokaryotes, fungi, and some protists also have cell walls)
• The cell wall protects the plant cell, maintains its
shape, and prevents excessive uptake of water
• Plant cell walls are made of cellulose fibers
• Nonliving
• permeable
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Vacuoles: Diverse Maintenance Compartments
• A plant cell or fungal cell may have one or
several vacuoles
• Some protozoans have contractile vacuoles so
they don’t go through cytolysis ( cell breaks)
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• Central vacuoles, found in many mature plant
cells, hold organic compounds and water,
wastes, 90% of the cell
Video: Paramecium Vacuole
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 6-15
Central vacuole
Cytosol
Nucleus
Central
vacuole
Cell wall
Chloroplast
5 µm
Chloroplasts: Capture of Light Energy
• Plastids –organelles that store pigments
• The chloroplast is a member of a family of
plastids
• Chloroplasts function in photosynthesis
• contain the green pigment chlorophyll, as well
as enzymes and other molecules
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 6-18
Ribosomes
Stroma
Inner and outer
membranes
Granum
Thylakoid
1 µm
The Endomembrane System: A Review
• The endomembrane system is a complex and
dynamic player in the cell’s compartmental
organization
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The endomembrane system regulates protein
traffic and performs metabolic functions in the cell
• Components of the endomembrane system:
– Nuclear envelope
– Endoplasmic reticulum
– Golgi apparatus
– Lysosomes
– Plasma membrane
• These components are either continuous or
connected via transfer by vesicles
• NO RIBOSOMES IN THIS SYSTEM
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Fig. 6-16-1
Nucleus
Rough ER
Smooth ER
Plasma
membrane
Fig. 6-16-2
Nucleus
Rough ER
Smooth ER
cis Golgi
trans Golgi
Plasma
membrane
Fig. 6-16-3
Nucleus
Rough ER
Smooth ER
cis Golgi
trans Golgi
Plasma
membrane
Explain in your own diagram …
Cells are unique for the function they do
• Pancreas – aids in chemical digestion,
secretes enzymes
• Eye – needs energy to absorb light
• Human red blood cells – needs space to carry
oxygen
What organelles would these cells have or
not have ?
Fig. 6-UN1
Cell Component
Concept 6.3
The eukaryotic cell’s genetic
instructions are housed in
the nucleus and carried out
by the ribosomes
Structure
Surrounded by nuclear
envelope (double membrane)
perforated by nuclear pores.
The nuclear envelope is
continuous with the
endoplasmic reticulum (ER).
Nucleus
Function
Houses chromosomes, made of
chromatin (DNA, the genetic
material, and proteins); contains
nucleoli, where ribosomal
subunits are made. Pores
regulate entry and exit of
materials.
(ER)
Two subunits made of riboProtein synthesis
somal RNA and proteins; can be
free in cytosol or bound to ER
Ribosome
Concept 6.4
The endomembrane system
regulates protein traffic and
performs metabolic functions
in the cell
Concept 6.5
Mitochondria and chloroplasts change energy from
one form to another
Extensive network of
membrane-bound tubules and
sacs; membrane separates
lumen from cytosol;
continuous with
the nuclear envelope.
Smooth ER: synthesis of
lipids, metabolism of carbohydrates, Ca2+ storage, detoxification of drugs and poisons
Golgi apparatus
Stacks of flattened
membranous
sacs; has polarity
(cis and trans
faces)
Modification of proteins, carbohydrates on proteins, and phospholipids; synthesis of many
polysaccharides; sorting of Golgi
products, which are then
released in vesicles.
Lysosome
Membranous sac of hydrolytic
enzymes (in animal cells)
Vacuole
Large membrane-bounded
vesicle in plants
Digestion, storage, waste
disposal, water balance, cell
growth, and protection
Mitochondrion
Bounded by double
membrane;
inner membrane has
infoldings (cristae)
Cellular respiration
Endoplasmic reticulum
(Nuclear
envelope)
Chloroplast
Peroxisome
Rough ER: Aids in synthesis of
secretory and other proteins from
bound ribosomes; adds
carbohydrates to glycoproteins;
produces new membrane
Breakdown of ingested substances,
cell macromolecules, and damaged
organelles for recycling
Typically two membranes
Photosynthesis
around fluid stroma, which
contains membranous thylakoids
stacked into grana (in plants)
Specialized metabolic
compartment bounded by a
single membrane
Contains enzymes that transfer
hydrogen to water, producing
hydrogen peroxide (H2O2) as a
by-product, which is converted
to water by other enzymes
in the peroxisome