the cell factory
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THE CELL
Chapter 7
Microscopy
Micrographs
Photograph of the view through a microscope
Light Microscopes
Electron Microscopes
Scanning EM
To look at the surface of cells/specimen
3-D images
Transmission EM
To look at internal structures of cells/specimen
Robert Hook (1665)
Englishman
cork
“cells”
Compound
microscope
Anton van Leeuwenhoek
(1660’S)
(LAY vun
Hook)
Holland
Single lens
microscope
Pond water
“animalcules”
Cell Theory
3 parts and key people
Cells
Basic units of life
Matthias Schleiden (1838)
German botanist
Plant cells
Theodor Schwann (1839)
German biologist
Animal cells
Rudolf Virchow (1855)
German physician
New cells could only
come from the division
of existing cells
Cell Theory
All living things are composed of one or
more cells
Cells are the basic units of structure and
function in living things
New Cells are produced from existing
cells
Lots of different shapes
and sizes of cells
Sizes
The body is made of 100 trillion cell (1014)
Extremely small…The human eye can see
.01 cm, a human cell is 5x smaller
5 to 50 micrometers…µm
How big is a micrometer?
1m=100cm=1,000,000 micrometers
1 micrometer=.000001m
Basically you can’t see it
Remember: KHDmDCM..micro..nano..pico
Chaos chaos
Largest protozoan
You can see without microscope
1000 micrometers
How many meters is this? .001 m
How many centimeters is this? 0.1 cm
2 things in every cell…
Surrounded by a barrier, cell membrane
At some point in their life they contain….
DNA
What is a Nucleus?
Plural: nuclei
Large, membrane enclosed
structure that contains the
cell’s genetic material in the
form of DNA
What is a membrane?
A thin layer of material that
serves as a covering or lining
2 categories for cells…
Prokaryotes (pro-care-ee-ohts)
No nucleus
Cell’s genetic material is not contained in the nucleus…found in NUCLEOID: Region in cytoplasm where DNA is found
Less complicated that eukaryotes
Some have internal membranes
Do NOT have membrane bound organelles
Carry out every activity associated with living things…which are…
Eukaryotes (you-care-ee-othts)
Contain nucleus in which the genetic
material is separated from the rest of the cell
Contains dozens of structures and internal
membranes
High Variety
Single celled or multi-cellular
Plants, animals, fungi, and protists
Eukaryotic cell
structure
The Cell factory
Organelles
Highly specialized structures within the cell
Little organs
2 major divisions of the eukaryotic cell
Nucleus
The “brain”
DNA
Cytoplasm
Portion outside the nucleus but inside the cell membrane
2 types of Eukaryotic cells
Plant cells
Animal cells
What are the differences? (write them down!!!)
Nucleus
Brain of the cell
Office of the factory
Contains nearly all the cell’s DNA and
with it the coded instructions for making
PROTEINS and other important
molecules
Nuclear envelope
Surrounds nucleus
Made of 2 membranes
Dotted with thousands of nuclear pores
How do we get messages, instructions and
blueprints out of the office?
Allow material to move in and out of nucleus by
using “little runners” such as proteins, RNA and
other molecules
Inside the nucleus we
see…
Contain a granular material called…
CHROMATIN
Chromatin= DNA + protein
Usually spread out in nucleus
During cell division, chromatin clumps
together or condenses…we call this….
CHROMOSOMES
In the nucleus…
Contain a granular material called…
CHROMATIN
Chromatin= DNA + protein
Usually spread out in nucleus
During cell division, chromatin clumps
together or condenses…we call this….
CHROMOSOMES
Chromosomes
Threadlike structures that contain genetic
information that is passed on from one
generation to the next
Nucleolus
Small dense region inside the nucleus
Function: assembly of ribosomes begin…
Ribosomes
Most important function of cell is… Making proteins
Proteins regulate a zillion different things
Like…
Proteins are assembled ON Ribosomes
Ribosomes are small particles of protein & RNA (what’s RNA?)
They follow instructions from the nucleus to make proteins…follow the orders from the “head haunchos” in the main office
Scattered throughout the cell
They are like little factories
If a cell’s main function is making proteins, how many ribosomes are you going to have?
Endoplasmic reticulum
(ER)
Internal membrane system
The site where the lipid components of the cell membrane are assembled, along with proteins and other materials exported from the cell
2 types
Smooth ER
Rough ER
Rough ER
Involved in protein making (synthesis)
So what are we going to see on it?
ribosomes
Once a protein is made, it leaves the ribosome and goes into the Rough ER
The rough ER then modifies the protein
All proteins that are exported by the cell are made on the RER
Membrane proteins are made on the RER too
Smooth ER
NO ribosomes on it
Looks smooth
Contains collections of ENZYMES that have
specialized tasks
What do enzymes do?
Tasks include:
Synthesis of membrane lipids
Detoxification of drugs
Liver cells
Big in detox therefore….what do u think liver cells have a
lot of?
Golgi Apparatus
Discovered by Italian scientist Camillo Golgi
Once proteins are done being “modified” in the
RER, they move onto the Golgi apparatus
Looks like a stack of pancakes
Function: modify, sort, and package proteins
and other materials from the ER for STORAGE
or SECRETION outside the cell
Proteins are “shipped” to final destination
They are the CUSTOMIZATION SHOP
Finishing touches on proteins before they leave
factory
Lysosomes
(Lie-so-soh-mz)
The factory’s clean-up crew
It’s an Organelle filled with enzymes
Function: Digestion (break down) of lipids, carbohydrates, and proteins into smaller molecules that can be used by the cell
Also digest organelles that have outlived their usefulness
What do you think happens if
lysosomes malfunction?
A bunch of “junk” build up in the
cell…why?
Is this good?
Many human diseases result from
malfunction of lysosome
Tay-Sachs disease
DNA does not make the enzyme
hexoaminidase A that breaks down
lipids in nerve cells
Build up of lipids in nerve cells
causes those cells to stop working
Noticeable 3-6 months after birth,
child lives to be about 4-5 years old
Vacuoles
The factory’s storage place
Only in certain cells
Sac-like organelles
Function: stores material such as water,
salts, proteins, and carbohydrates
Plant cells have a single, large central
vacuole
Pressure of central vacuole allows plants to
support heavy structures
Single-celled organisms and
some animals also have
vacuoles…
Paramecium
Contractile vacuole
Contracts rhythmically to pump excess water
out…this maintains what?
homeostasis
What is the one thing
all living things need
to eat, breath,
reproduce, move and
much more?
ENERGY!!!!
Two ways cells get
energy…
From food molecules
From the sun
Mithochondria
Convert chemical energy stored in food
into compounds that are more convienent
for the cell to use
Has 2 membranes
Inner membrane
Outer membrane
In Animal AND Plant cells
Nearly all come from the ovum
You get your mitochondria from your mom!
Chloroplasts
Plant and some Bacteria cells only ( NOT in animal cells)
Capture energy from the sunlight and convert it into chemical energy…what is this process called?
PHOTOSYNTHESIS
Like solar power for plants
2 membranes
Inside: large stacks of other membranes that contain chlorphyll
Organelle DNA
Chloroplasts and
mitochondria contain their
own genetic info
In form of small, circular
DNA molecules
mDNA
Lynn Margulis
American biologist
Chloroplasts and
mitochondria are
descendents of
prokaryotes
She said…
Ancient Prokaryotes from wayyyyy back in the
day had a symbiotic relationship with the
ancient eukaryotes
What is symbiotic? (review ecology!!!)
The prokaryotes lived inside the eukaryotes
There were prokaryotes that used oxygen to
make energy (ATP)
Mitochondria
There were prokaryotes that used
photosynthesis to get energy
Chloroplasts
Endosymbiotic Theory
Idea that
mitochondria and
chloroplasts evolved
from prokaryotes
Cytoskeleton
Supporting structure and
transportation system
Network of protein filaments that helps the cell to maintain its shape and to help the cell move
2 main type of filaments
Microtubules
Microfilaments
(Intermediate filaments is a 3rd type)
Microfilaments
Threadlike structures
Made of protein called ACTIN
Extensive networks
Tough, flexible framework
Help cells move
Assembly and disassembly helps cells
move (like amoebas)
Microtubules
Hollow structures
Made of proteins called TUBULINS
Maintain cell’s shape
Important in cell division
Make mitotic spindle (separates
chromosomes)
Help build projections from cell surface…
Cilia and Flagella
Plural: cilium and flagellum
Cilia: hundreds of extension of the cell membrane that move like
the oars of a boat
Flagella: one or two long extensions off the cell that move in a
whip like fashion
Enable cells to swim rapidly through liquid
Centrioles
Only animal cells
Made of protein
TUBULIN
What else is made of
tubulin?
Near nucleus
Help organize cell
division
Antwon van Leeuwenhook
Robert Hook
Cell
bacteria
Cell Theory
Electron microscope
Prokaryote
Eukaryote
Organelles
Cytoplasm
Nuclear envelope
Chromatin
Nucleus
nucleolus
Ribosome
Smooth ER
Rough ER
Chromosome
Vacuole
Osmosis
Endocytosis
exocytosis
Proteins
DNA
RNA
Microscope
Micrograph
Magnifier
Lens
Contractile vacuole
Central Vacuole
Centrioles
Centrosomes
Nuclear pores
Nuclear-plasm
Stomata
ATP synthase
Chlorophyll
Cell membrane
Cell Wall
Cellulose
Phospholipids
Thylakoid
Cristae
Matrix
Inner membrane
Outer memebrane
Golgi apparatus
Micrometer
Millimeter
Picameter
Lysosome
Vacuole
Mitochondria
Chloroplast
Cytoskeleton
Centriole
Mictrotubule
Microfilament
Theodor Schwann
Matthias Schleiden
Rudolph Virchow
Lynn Margulis
Endosymbiotic Theory
Cilia
Flagella
Photosynthesis
Pseudopodia
Aquaporin
Transmembrane protein
Facilitated diffusion
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