Transcript Cell Basics

Cell Basics
Two Basic Cell Types
All cells are either
prokaryotic
or
eukaryotic
Eukaryotic cells
• Complex cells that
contain a nucleus
and many
membrane-bound
organelles with
specialized functions.
• Animal or plant cells.
(also includes fungi and
protists)
Nucleus
• Controls activities of the cell and holds the genetic
information (DNA)
• Surrounded by the nuclear membrane/envelope
• Ribosomes, which will later be used in protein
synthesis, are partially assembled in an area called
the nucleolus
• The nucleus is known
as the “control
center” of the cell
and is found in all
eukaryotic cells. For
example, plant and
animal cells.
Lets quickly examine the structure and function
of the cell membrane:
Which of the following animals do you
think can pass easily through this opening?
Why?
Cell Membrane
• Regulates what goes in and out of the cell
(selective).
• Composed of lipids and proteins.
Cytoplasm
• Cytoplasm is a clear,
jelly-like fluid that
fills the cell
Ribosomes
• Make proteins.
• Found throughout the cell and on rough ER.
Endoplasmic Reticulum (ER)
• System of internal membranes that transport
proteins and other substances through the
cell.
• 2 Kinds:
–Rough ER: transports proteins that are made
by ribosomes attached to it
–Smooth ER: helps make new lipids and helps to
break down toxic substances such as alcohol
• Has no ribosomes attached to it
Which picture best depicts the function of
the ER?
• The ER is referred to as
the highway of the cell
since it transports
molecules, such as
proteins, throughout the
cell.
Golgi Apparatus
• Flattened, membrane-bound sacs that serve as
the packaging and distribution center of the cell.
– They modify the proteins that travel from the ER in
vesicles (small, membrane-bound sacs) before
they are released to serve their function.
Which picture best depicts the function of
the golgi apparatus?
• The Golgi is sometimes
referred to as the
post office since it
modifies and packages
proteins before they
are shipped to their
rightful destination
Mitochondria
• Releases energy from organic compounds to
make ATP (energy)
• “Powerhouse” of the cell
Fact: Mitochondria contain their own DNA and ribosomes to make
their own proteins. Who do you inherit your mitochondrial DNA
from?
• Your mother –it’s found within the egg and the father only donates his
DNA (23 chromosomes)
Mitochondria
• Look at the mitochondrial DNA and
determine whether it looks like picture a or b.
Mitochondrial DNA similar to Prokaryotic
(bacterial) DNA?
• This fact supports the widely accepted
theory that mitochondria were once
primitive prokaryotes!
Which picture best depicts the function
of the Mitochondria?
TXU supplies
electricity to many
houses and
businesses in Dallas
just as the
mitochondria
supplies energy for
it’s cell
Based on your knowledge of
mitochondria, which of the following
cells would contain a greater number of
mitochondria?
• Muscle cells require large amounts of energy in
order to perform functions and therefore
require a larger number of mitochondria
Lysosomes
• Specialized vesicles that contain digestive
enzymes
– Function by digesting and recycling the cell’s used
components (carbs, proteins, lipids and old
organelles)
Which picture best depicts
the function of the lysosome?
• Both contain
digestive enzymes
and both help to
breakdown particles
Cytoskeleton
• A network of
protein structures
that determines cell
shape
• Provides support
for organelles and
pathways for cell
movement.
Some structures are found in plant
cells but not animal cells…
Cell wall
• Helps support, protect and maintain the shape
of the cell
Chloroplasts
• Use light energy to make carbohydrates from
carbon dioxide and water (photosynthesis).
• Just like mitochondria, chloroplasts contain
their own DNA and are also thought to be
descendents of ancient prokaryotic cells
“Large” Central Vacuole
• Stores water and may contain many
substances, including ions, nutrients, and
wastes
• Largest organelle found in plants
• When full of water, the cell becomes rigid
(turgor pressure)
• FYI: Small vacuoles are
found in animal cells.
Cell Organelles
Cell Membrane
Mitochondria
Chloroplast
Endoplasmic Reticulum
Nucleus
Vacuole
Lysosome
Golgi Body
Ribosome
• Animal
Cell Wall
• Plant
Prokaryotes, which includes all bacteria. They
are the simplest cellular organisms. They have
genetic material but no nucleus.
Typical bacteria cell
Prokaryotic cells
• Unicellular
• No membrane bound
organelles –
therefore, not many
specialized functions.
Bacteria!
Flagella
• Tail-like structure
that helps bacteria
move (MOTILITY)
• Flagella are also
found on some
eukaryotic cells.
• For example, some
protists have
flagella. So do
sperm cells!
Pili
• Hair-like structure that helps bacteria stick
to surfaces
Capsule
• A sticky outer
protective covering
that allows bacteria to
adhere to surfaces
• Increases their ability
to cause disease
Name the structures of this bacterium.
1.
2.
3.
4.
5.
6.
7.
Different Types of Cells
• Prokaryotic
no nucleus
• Eukaryotic
nonucleus
nucleus
nucleus
small ribosomes
larger
ribosomes
small ribosomes
larger ribosomes
no organelles
noorganelles
organelles
organelles
very small 1-10µm
only in bacteria
verysmall
small
small 2-1000µm
protists, fungi, plants, protists, fungi, plants,
only in bacteria
animals
animals