Transcript Cells

Cells
Organelles
History
• 1590 The invention of
the electron microscope
led to the discovery of
organelles within the
cell
• They use a beam of
electrons instead of
light to produce a
magnified image
Present
• Scientists use video
cameras and computer
processing to observe
the movement of cell
organelles.
• But in the future
nanotechnology will be
used to manipulate
organelle functions.
•
https://www.youtube.com/watch?
v=6LOednv-nQ4
Cells
• Cells carry on the many
functions needed to
sustain life.
• They grow and divide,
thereby producing more
cells.
• This requires that they
take in nutrients, to
provide energy for the
work that cells do and to
make the materials that a
cell or an organism needs.
Two Types of Cells
• Eukaryotes
• Cells with a nucleus and
all sorts of organelles.
• Prokaryotes
• A prokaryote is a single cell
or organisms that does NOT
have nucleus.
Cells
• According to cell
theory, cells are the
main unit of
organization in biology.
• Whether you are a
single cell or a blue
whale with trillions of
cells, you are still made
of cells.
Cell Membrane
• Controls what substances come
in and out of the cell.
• When you think about a
membrane, imagine it is like a big
plastic bag with some tiny holes.
That bag holds all of the cell pieces
and fluids inside the cell and keeps
any nasty things outside the cell.
The holes are there to let some
things move in and out of the cell.
Cells
• Cell Membrane
– The proteins
that cross the
bilayer are very
important in
the active
transport of ions
and small
molecules.
Cell Membrane
• Active Transport – moving
materials across the cell
membrane.
– Requires Energy
• Passive Transport – moving
materials across the cell
membrane.
– Does Not Require energy
– Diffusion and Osmosissubstances move from areas
of high to low concentration
Cell and its Organelles
Cytoplasm
• The fluid that fills a
cell.
• Also called cytosol
Nucleus
• Command center the
Cell
– acts like the brain
• It is the big dark spot
somewhere in the
middle of all of
the cytoplasm
Mitochondria
• The powerhouses of
the cell.
• Acts like a digestive
system
• Takes in nutrients,
breaks them down, and
creates energy rich
molecules for the cell.
Mitochondria
• Cellular respiration
happen in the
mitochondria.
• Keep the cell full of
energy.
• Cells that require more
energy have more
mitochondria.
Endoplasmic Reticulum
• Functions as a
manufacturing and
packaging system.
• It is a network of
membranes found
throughout the cell and
connected to the nucleus.
• Carries proteins and other
materials throughout the
cell.
– Transport of materials
Nucleolus
• Produce ribosomes.
– A ribosome production factory.
• Ribosomes produce proteins.
Ribosomes
• Protein Construction Teams
• Protein builders or the
protein synthesizers of the cell.
• Cells Need Proteins.
– speed up biological processes.
– support cell functions
• Attach to the surface of the
endoplasmic Reticulum.
• Smallest and most abundant
organelle that makes proteins by
linking amino acids
Lysosomes
• A lysosome is basically a
specialized vesicle that
holds a variety of
enzymes.
• Breaks down particles
and worn out cell parts.
– Digest food or break down
the cell when it dies.
• Contributes to the aging
process in humans.
• Float in the cytoplasm
until they are needed.
Vacuoles
• Storage bubbles.
• Water filled sack
floating in the
cytoplasm.
• Stores food, waste,
and/or other materials.
Plant Cells
• Plant cells have an additional
protective layer.
• Cell Wall – Rigid layer of non
living material
– Animal cells DO NOT have a cells
wall.
– Helps support
– While cell walls protect the cells,
they also allow plants to grow to
great heights. You have
a skeleton to hold you up.
Cell Membrane
• The cell membrane surrounds, protects,
keeps the cytoplasm inside.
• There are small holes, in the cell walls
between plant cells. The cell membranes of
neighboring cells are able to connect
through these holes.
• The connections allow the transfer of
nutrients, waste, and ions.
• Helps with the movement of materials in
and out of the cell.
– Food
– Oxygen