Download Biology and you - properties of life and the scientific method

Cells & Their Structure and Function
Cell Essential
• How does the structure of a cell impact its function for the living organism?
Question.
Discovery of cells
How were they
discovered?
Using a compound microscope
Who discovered
them?
Robert Hook
What was he looking
at?
cork
Why were they
called cells?
Because they were big rectangles that
reminded him of the monks housing
that was referred to as a cell
Cell Theory:
1. Matthais Schleiden-(1838) concluded that all plants are made of cells
2. Theodor Schwann-(1839) concluded that all animals are composed of cells
3. Rudolph Virchow-(1855) determined that cells come only from other cells
Three Main Ideas of Cell Theory
1.All organisms are composed of one or more cells
2.Cell is the basic unit of structure and organization of organisms
3. All cells come from pre-existing cells
Cell Basics:
1. Structure must compliment the function.
2. Cells varies widely because they are capable of doing many things.
3. Size plays a role in its function.
4. A cell’s size is limited by its surface area to volume ratio.
2 major types of cells
1. Prokaryote- lacks a nucleus and most internal structures found in eukaryotic
cells. Only contain DNA and/or RNA and ribosomes along with cell wall,
cytoplasm and plasma membrane. They are both much smaller than eukaryotic
cells.
Pro means no. Bacteria is the only Prokaryote
2. Eukaryote-Has a nucleus surrounded by a membrane and has other internal
organelles surrounded by membranes. Protist, fungi, animal, and plant
Are just like you, Starts with an E- they’re evolved
2 Major Types of Eukaryotes:
a. Animal-Tend to be round, smaller than plant cells
b. Plant-Larger in size, squarish/rectangular in shape
Organelles: specialized subunit within a cell that have a specific function or job
Organelle
Function
Control center
Nucleus
Cell Wall
Support and protect
cells
Structure
Cell Types
Big round circle in
Prokaryotes
the center of the cell Plants
Animals
Tough fairly rigid
layer that surrounds
some type of cells
Regulates what’s
goes in and out of a
cell
Is a phospholipid bio
layer. Separates
interior of cell from
exterior
Energy power house Pill shaped with a
Mitochondria The folds create more folded membrane
energy because it has inside
more surface area
Cell storage unit
Plants -singular
Vacuoles
Food/water/waste
rectangular and large
Animals -many
small ones
Converts sunlight
Oval with small
Chloroplasts into food sugar
round disks in it
Plasma
Membrane
Protein builders
Ribosomes
Small dots
throughout the cell
Prokaryotes
Plants
Animals
Prokaryotes
Plants
Animals
Prokaryotes
Plants
Animals
Prokaryotes
Plants
Animals
Prokaryotes
Plants
Animals
Prokaryotes
Plants
Animals
Prokaryotic vs. Eukaryotic cells
Question
Prokaryotic
Eukaryotic
Does it have a
nucleus?
no
yes
Does it have
membrane bound
organelles?
What kind of
organisms is it
found in?
no
yes
Examples
E.coli
Which cell evolved
first?
This one
Animals/plants/fungi/protists
bacteria
Red blood cells
Cell Membrane:
AKA—plasma membrane.
It helps maintain hemostasis
Homeostasis-regulation of internal environment
Plasma membrane acts as a selectively permeable membrane; which means: things are
only chosen to go through, things don’t just go through by themselves
Cell diversity:
1.size
2.shape
3.internal organization
Why do cells differ in size, shape and organization?
To preform different functions. Shaped to make it move/or even stay put.
Plant cells are different from animal cells in many ways. A plant cell is much larger
than an animal cell because it needs to produce its own food. Because a plant cell
produces its own food it has chloroplasts something an animal cell wouldn’t need.
Animal cells are round and plant cells are boxy. An animal cell has no cell walls while
a plant cell does. That is why plants don’t move. A eukaryotic cell has membrane
bound organelles while prokaryotic cells have no membrane and their organelles are not
membrane bound.