I say I say I say boy,
What the Cell?
An introduction to
cells and their
organelles!
Cells! Who wants some?!
Not that type, but this
kind…
Cells have a lot of variety and some
exists as living, mobile entities
More observations…
• Finally in the 1800’s, after the scientific community observed
and recorded cell activities, they concluded this-The Cell
Theory:
1) Living things are composed of cells.
2) Cells are the basic units of structure
and function of living things.
3) Cells come from other cells
The Tree of Life
At the base, one cell gave rise to species now and once
upon a time. It was probably a self-replicating, bacterial
cell. It’s also called the Last Universal Common Ancestor
or LUCA.
These guys are old!
This guy is too, but the oldest,
known bacteria dates back to about
3.5 Billion Years Ago. Our current
clock’s at 6 Billion years.
Their DNA is also our DNA. At least
genes that control metabolism, energy,
and replicating DNA.
There was a split though!
From LUCA, there came two camps:
Prokaryotes. Prokaryotes have genetic material, but it’s
not contained in a membrane (nucleus). An example’s
your basic bacterial cell. Think: simpler.
Eukaryotes. Eukaryotes have genetic material bound in a
membrane. An example is us. Think: complex.
PRO -- NO
NO Nucleus
EU -- TRUE
EU it’s true they
DO have a
nucleus
Prokaryotes
These fellahs, despite their simplicity, carryout activities like any other living
creature; in fact, they grow reproduce, respond to their environment and
can move. They are older and smaller than Eukaryotes.
The Prokaryotes
• Generally smaller and simpler than eukaryotes
• Key: have genetic material that is not contained
in the nucleus
• Less “complicated” than eukaryotes but still
carry out all aspects of “life”
• Bacteria are prokaryotes
Some Prokaryotic Examples
Eukaryotes
These fellahs contain
internal structures
wrapped in a
membrane. Think:
tiny organs, or,
organelles.
Some eukaryotes live as single-celled organisms; others form large,
multicellular organisms like plants, animals, fungi, and protists.
My Friends the Eukaryotes
• You are made of Eukaryotic cells!!!
• Usually contain dozens of structures and
internal membranes
• Key: Contain a nucleus in which genetic
material is separated from the rest of the
cell
• Can be highly specialized
• Much larger and more complex than
prokaryotes
• Can be single celled or multicellular:
humans, hamsters, venus fly traps, etc.
Some of our Eukaryotic friends
Cell Types
What is an organelle?
• Membrane bound structure that has a
job
to do in eukaryotic cells
• They’re not in Prokaryotes! (bacteria)
• Plant cells have an organelle that
animals don’t
• Animals have one organelle plants don’t.
Plant vs Animal
VS
Plant Cell
Animal Cell
Nucleus
• Control Center
• Contains nearly all DNA – instructions for making
proteins and other important molecules
• Surrounded by nuclear envelope
– Dotted with nuclear pores = stuff in and out
• Nucleolus – small dense region where
assembly of ribosomes begins
Chromosome
• (The Data) … all the directions
• (DNA)
Nucleolus
• A structure that is within the nucleus that produces
ribosomes
Endoplasmic Reticulum
• Transportation
• Rough Endoplasmic
Reticulum (RER)
– Covered in ribosomes (rough)
– Makes and transports proteins,
especially membrane proteins
• Smooth Endoplasmic
Reticulum (SER)
– Synthesis of membrane lipids
– Contain enzymes that can
detoxification of drugs – Liver
has lots of SER’s
Notice how the E.R. is
attached to the nucleus
…. Like the ‘hallways’
Ribosomes!
• Protein Factory
• Proteins are assembled on these organelles by
following coded instructions from the nucleus
Smooth and Rough ER
Nuclear
Pores
review!
Nuclear
Envelope
ER
Nucleus
Ribosomes
Golgi Apparatus
• Packaging Center
• Modify, sort, and package proteins and other
materials from the endoplasmic reticulum for
storage or secretion.
Mitochondria
• Power House
• Convert chemical energy stored in food to a
form a cell can use (ATP)
• In humans you get all of you mitochondria from
your mom
• Contain own
‘Mitochondrial DNA’
• Has double membrane
Chloroplast
• Food Factory
• Only in plants
• Captures energy from the sun and converts it
into chemical energy by a process called
photosynthesis
• Has double membrane
Mitochondria/Chloroplasts
• These two utilize energy from food and the sun
respectively and convert it into energy the cell can
use.
Cytoskeleton
• Cell Framework
• A network of protein filaments
that helps the cell to maintain its
shape
Vacuoles
• Storage Facility
• More prevalent in plants
• Store materials like water, salts, proteins, and
carbohydrates
• In plants, there is a large vacuole which helps with
maintaining pressure.
– Allows plant to support heavy
loads like leaves and branches
Lysosome
• Waste Management
• In animal cells ONLY
• Have enzymes used to break down lipids,
carbohydrates, and proteins
• breaking down old organelles
Cell boundaries aka cell membrane
• Cell membrane regulates what enters/leaves the cell.
Here’s the protein channel embedded in the
cell membrane-doors
Cell Wall
•
•
•
•
Castle Wall
Only in Plant Cells
Provides support an protection for cell
Mostly made of cellulose
– Cellulose is the key component of wood and paper
Come on baby let’s do the
locomotion……
• Cilia
• Flagella
Plant Cell
Animal Cell
The End . . . Or The Beginning