Download CELL - OCC

Cells
(Chapter 3)
Developed by Dave Werner
OCC BIOL-114
Spring 2014
OBJECTIVES:
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Outline the discoveries that led to the
development of the Cell Theory.
State the cell theory.
Describe the relationship between cell
shape & cell function.
Distinguish between prokaryotes and
eukaryotes.
3.1 History
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1. In 1660, the English Scientist Robert Hooke used a
microscope to examine a thin slice of cork and described it as
consisting of "a great many little boxes". Named “cells”.
2. 1673, Antony Von Leeuwenhoek – improved lenses and
advanced cell biology by viewing red blood cells and sperm.
3. 1838, German Botanist Matthias Schleiden - PLANT cells
4. 1839, German Zoologist Theodor Schwann –ANIMAL
cells
5. In 1855, German Physician Rudolf Virchow induced that
THAT CELLS ONLY COME FROM OTHER CELLS".
6. His statement contradicted the idea that life could arise
from Nonliving Matter. "Theory of Spontaneous
Generation" The process by which life begins when ethers
enter nonliving things.
CELL THEORY
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A. All living things are composed of
one or more cells.
B. Cells are the basic units of
structure & function in an
organism.
C. Cells come only from
reproduction of existing cells.
How Do We “See” Cells?
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Compound Light
Microscope
TEM
SEM
So What is “A Cell”?
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The CELL is the smallest unit of matter that
CAN Carry on ALL the PROCESSES OF LIFE.
Both Living and Nonliving Things are
composed of molecules made from chemical
elements such as carbon, hydrogen,
oxygen, and nitrogen.
The organization of these molecules into Cells
is one feature that distinguishes Living Things
from all other matter.
CELL SHAPE - Video
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Variety of Shapes
SHAPE DEPENDS ON
FUNCTION – Examples?
Example:Cells of Nervous
System that carry
information from your toes to
your brain are long and
threadlike.
6. Blood Cells are shaped
like round disk that can
squeeze through tiny blood
vessels.
INTERNAL
ORGANIZATION
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1. Cells contain a variety of Internal
Structures called ORGANELLES.
2. An organelle PERFORMS SPECIFIC
FUNCTIONS FOR THE CELL.
3. The entire cell is Surrounded by A THIN
MEMBRANE, called the CELL MEMBRANE
4. A Large Organelle near the Center of the
Cell is the NUCLEUS. IT CONTAINS THE
CELL'S GENETIC INFORMATION AND
CONTROLS THE ACTIVITIES OF THE CELL.
Why Aren’t Cells Bigger?
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Surface-to-volume
ratio
3.2 Different Cell Types Characterize Life’s
Three Domains
Introducing Prokaryotic Cells
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1. ORGANISMS WHOSE CELL
CONTAIN A NUCLEUS AND
OTHER MEMBRANE-BOUND
ORGANELLES ARE CALLED
EUKARYOTES.
2. ORGANISMS WHOSE CELLS
NEVER CONTAIN (OR LACK) A
NUCLEUS AND OTHER
MEMBRANE-BOUND
ORGANELLES ARE CALLED
PROKARYOTES.
Examples of Each???
Differences between
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UNICELLULAR ORGANISMS such as
bacteria and their relatives are
Prokaryotes.
Prokaryotes are placed in Two
Kingdoms, Separate from Eukaryotes.
All other organisms are Eukaryotes;
plants, fish, mammals, insects and
humans.
4.2 Prokaryotic Cells (fig.4.3)
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Believed to be the
first cells to evolve.
Lack a membrane
bound nucleus and
organelles.
Genetic material is
naked in the
cytoplasm
Ribosomes are only
organelle.
Http.micro.magnet.fsu.edu/cells.html
Cell Wall
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Rigid peptidoglycan
- polysaccharide
coat that gives the
cell shape and
surround the
cytoplasmic membrane. Offers
protection from
environment.
Http://micro.magnet.fsu.edu/cells/bacteriacell.ht
ml
Plasma Membrane
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Layer of phospholipids and proteins
that separates
cytoplasm from
external
environment.
Regulates flow of
material in and out
of cell.
Http://micro.magnet.fsu.edu/cells/bacteriacell.ht
ml
Cytoplasm
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Also known as
proto-plasm is
location of growth,
metabolism, and
replication. Is a gellike matrix of water,
enzymes, nutrients,
wastes, and gases
and contains cell
structures.
Http://micro.magnet.fsu.edu/cells/bacteriacell.ht
ml
Ribosomes
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Translate the
genetic code into
proteins.
Free-standing and
dis-tributed
throughout the
cytoplasm.
Http://micro.magnet.fsu.edu/cells/bacteriacell.ht
ml
Nucleoid
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Region of the
cytoplasm where
chromosomal DNA is
located. Usually a
singular, circular
chromosome.
Smaller circles of
DNA called plasmids
are also located in
cytoplasm.
Http://micro.magnet.fsu.edu/cells/bacteriacell.ht
ml
Mesosome
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Infolding of cell
membrane.
Possible role in cell
division.
Increases surface
area.
Photosynthetic
pigments or respiratory chains here.
Http://www.med.sc.edu:85/fox/protobact.jpg
Prokaryotic vs. Eukaryotic
Http://micro.magnet.fsu.edu/cells.html
3.3 Plasma Membrane
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Phospholipid bi-layer
that separates the
cell from its
environment.
Selectively
permeable to allow
substances to pass
into and out of the
cell. (Fig. 3.10-3.11)
Http:micro.magnet.fsu.edu/cells/animal/plasma
Proteins (Fig 3.12)
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Transport Proteins
Enzymes
Recognition Proteins
Adhesion Proteins
Receptor Proteins
3.4 Eukaryotic Organelles
Divide Labor
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OBJECTIVES:
Describe the structures, composition, &
function of the cell membrane.
Name the major organelles found in a
Eukaryotic cell, and describe their function.
Describe the structure and function of the
nucleus.
Describe three structures characteristic of
plant cells.
Eukaryotic Cells (Table 3.2)
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“True nucleus”;
contained in a membrane bound
structure.
Membrane bound
organelles.
Thought to have
evolved from
prokaryotic cells.
Http:micro.magnet.fsu.edu/cells/animalcell.html
CYTOPLASM
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EVERYTHING BETWEEN THE CELL MEMBRANE AND THE
NUCLEUS = CYTOPLASM.
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Consists of TWO MAIN COMPONENTS: CYTOSOL and
ORGANELLES.
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CYTOSOL = jellylike mixture that consists MOSTLY OF WATER,
along with PROTEINS, CARBOHYDRATES, SALTS, MINERALS
and ORGANIC MOLECULES.
Suspended in the Cytosol are tiny ORGANELLES (ORGANS).
ORGANELLES ARE STRUCTURES THAT WORK LIKE
MINIATURE ORGANS, THEY CARRY OUT SPECIFIC FUNCTIONS
IN THE CELL.
Any analogies???
Ribosomes
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Translate the genetic code
into proteins = Protein
Synthesis.
Found attached to the
Rough endoplasmic
reticulum or free in the
cytoplasm.
60% RNA and 40%
protein.
Http://micro.magnet.fsu.e
du/cells/animals/ribosome
s.html
Ribosome
Http://cellbio.utmb.edu/cellbio/ribosome.htm
Rough Endoplasmic Reticulum
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Network of
continuous sacs,
studded with
ribosomes.
Manufactures, processes, and
transports proteins
for export from cell.
Continuous with
nuclear envelope.
Http://micro.magnet.fsu.edu/cels/animal/endopl
Endoplasmic Reticulum
(Fig 3.15)
Http://cellbio.utmb.edu/cellbio/ribosome.htm
Smooth Endoplasmic
Reticulum
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Similar in appearance to rough ER, but
without the ribosomes.
Involved in the production of lipids,
carbohydrate metabolism, and
detoxification of drugs and poisons.
Metabolizes calcium.
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Http://micro.magnet.fsu.edu/cells/animals/endoplasmicreticulum.html
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Lysosome (Fig 3.17)
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Single membrane
bound structure.
Contains digestive
enzymes that break
down cellular waste
and debris and
nutrients for use by
the cell.
Http://micro.magnet.fsu.edu/cells/animals/lysos
ome/html
Lysosome
Http://anatomy.med.unsw.edu.au/teach/phph1004/1998/WWWlect3/sld005.htm
Golgi Apparatus (Fig 3.16)
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Modifies proteins
and lipids made by
the ER and prepares
them for export
from the cell.
Encloses digestive
enyzymes into
membranes to form
lysosomes.
Http://micro.magnet.fsu.edu/cells/animals/golgi
apparatus.html
Golgi Apparatus
Http://cellbio.utmb.edu/cellbio/golgi.htm
Mitochondrion =
“Powerhouse” of the Cell
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Membrane bound
organelles that are
the site of cellular
respiration (ATP
production)
Fig. 3.20
http://micro.magnet.fsu.edu/cells/animals/mitoc
hondrion/html
Mitochondrion
Http://anatomy.med.unsw.edu.au/teach/phph1004/1998/WWWlect3/sld005.htm
Nucleus (Fig 3.14)
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Double membranebound control center
of cell.
Separates the
genetic material
from the rest of the
cell.
Http://micro.magnet.fsu.edu/cells/animals/nucle
us/html
Nucleus
Http://cellbio.utmb.edu/cellbio/nucleus.htm
Parts of the nucleus:
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Chromatin - genetic material of cell in
its non-dividing state.
Nucleolus - dark-staining structure in
the nucleus that plays a role in making
ribosomes
Nuclear envelope - double membrane
structure that separates nucleus from
cytoplasm.
Cell Wall
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Protects and gives
rigidity to plant cells
Formed from fibrils
of cellulose
molecules in a
“matrix” of
polysaccharides and
glycoproteins.
Http://micro.magnet.fsu.edu/cells/plants/cellwal
l.html
PLANT CELLS
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1.
2.
2 Additional Structures Not
found in animals cells
CELL WALLS
PLASTIDS
PLASTIDS
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MAKE OR STORE FOOD
CHLOROPLAST, (figure 4-17) an organelle that
converts SUNLIGHT, CARBON DIOXIDE, AND WATER
INTO SUGARS. This process is called
PHOTOSYNTHESIS
Each Chloroplast encloses a system of Flattened,
Membranous Sacs called THYLAKOIDS. It is in the
Thylakoids that Photosynthesis occurs
Chloroplasts are GREEN because they contain
CHLOROPHYLL, a PIGMENT that ABSORBS
ENERGY IN SUNLIGHT. THEY ARE FOUND ONLY IN
ALGAE, SUCH AS SEAWEED, AND IN GREEN PLANTS.
Other PLASTIDS store reddish-orange pigments that
color fruits, vegetables, flowers, and autumn leaves
Chloroplast Fig. 3.19
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Site of
photosynthesis
Membrane bound
structure.
Contains chlorophyll
http://micro.magnet.fsu.edu/cells/plants/chlorop
last.html
Chloroplast
Www.ultranet.com/~jkimball/BiologyPages/C/Chloroplasts.html
Vacuole
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Plants have large
central vacuoles that
store water and
nutrients needed by
the cell.
Help support the
shape of the cell.
Http://micro.magnet.fsu.edu/cells/plants/vacuol
e.html
Animal Vacuole
Www.puc.edu/Faculty/Bryan_Ness/vacuole_TEM.htm
Plant Cell Vacuole
Www.bio.mtu.edu/campbell/plant.htm
Animal Cell vs. Plant Cell
Http://:micro.magnet.fsu.edu/cells/html
3.5 The Cytoskeleton Supports
Eukaryotic Cells
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In Animal Cells, an internal framework
called CYTOSKELETON maintains the
Shape of the Cell (Fig. 3.23)
TWO Types of structures:
MICROFILAMENTS
MICROTUBULES
MICROFILAMENTS
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NOT HOLLOW and have a
structure that resembles ROPE
made of
TWO TWISTED CHAINS OF
PROTEIN called ACTIN.
CONTRACT, causing movement.
Muscle Cells
MICROTUBULES (Fig. 3.24)
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HOLLOW TUBES like plumbing pipes. They are
the Largest Strands of the Cytoskeleton.
Made of a PROTEIN called TUBULIN.
THREE FUNCTIONS:
A. To maintain the shape of cell.
B. To serve as tracks for organelles to move
along within the cell.
C. When the Cell is about to divide, bundles
of Microtubules known as SPINDLE FIBERS
come together and extend across the cell to
assist in the movement of Chromosomes during
Cell Division
Microfilaments
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Solid rods of
globular proteins.
Important
component of
cytoskeleton which
offers support to cell
structure.
Http://micro.magnet.fsu.edu/cells/animals/micro
filaments.html
Centrioles
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Found only in animal
cells.
Self-replicating
Made of bundles of
microtubules.
Help in organizing
cell division.
Http://micro.magnet.fsu.edu/cells/animals/anim
as/centrioles.html
How Do Cells Move?
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Cilia and Flagella
External appendages
from the cell
membrane that aid
in locomotion of the
cell.
Cilia also help to
move substance
past the membrane.
Http://micro.magnet.fsu.edu/cells/animals/ciliaa
ndflagella.html