Transcript Cells Lect 1 diversity , size, pro vs. euk

Cells
Diversity, Size, Basic parts
And
Prokaryotes vs. Eukaryotes
Cellular Organization
Life is Highly Organized
Living things are organized in a
“Hierarchical” manner – meaning one level
is integrated into the next higher level,
increasing in complexity
Explain: Cell Diversity
Cells within the same organism show
Enormous Diversity in:
1. Size
2. Shape
3. Internal Organization
1. Cell Size
Female Egg - largest cell in the human
body; seen without the aid of a microscope
about the size of a grain of salt
Most cells are visible only with a
microscope.
Cells are small for 2 Reasons
Reason 1:
Limited in size by the RATIO between their Outer
Surface Area and Their Volume.
A small cell has more SURFACE AREA than a
large cell for a GIVEN VOLUME OF CYTOPLASM.
Why cells are small
 As a cell grows
larger at some
point its surface
area becomes too
Small to allow
nutrients it needs
to survive quickly
enough to meet the
cell's need.
Cells are Small
Reason 2:
THE CELL'S
NUCLEUS (THE
BRAIN) CAN
ONLY CONTROL
A CERTAIN
AMOUNT OF
LIVING, ACTIVE
CYTOPLASM.
2. Cell Shape
Diversity of form reflects a
diversity of function.
THE SHAPE OF A CELL
DEPENDS ON ITS
FUNCTION.
What is this? Structure = function
What is this? Structure = function
What is this? Structure = function
Cells size shape form
http://www.youtube.com/watch?v=Ssf
SyFliU0M
3. Internal Organization
Basic Parts of a Cell
All Cells have:
Plasma membrane
Cytoplasm
Control Center
Plasma membrane
The cells outer boundary – a barrier
between the inside and outside of a cell
Cytoplasm
The region that is within the plasma
membrane - includes fluids and
organelles
Control Center
Cells carry coded
information in the
form of DNA .
In some cells it
floats freely
In others it is
surrounded by a
membrane and
called a nucleus
3. Internal Organization
Cell membrane
Cytoplasm
Prokaryotic Cell
Cell membrane
Cytoplasm
Eukaryotic Cell
Nucleus
Organelles
Two Basic Types of Cells
Prokaryotic Cell
DNA floats in
cytoplasm
Two types of cells
Eukaryotic Cells
DNA bound in
membrane =
nucleus
Compare and Contrast
Make a venn diagram comparing and
contrasting Prokaryotes vs.
Eukaryotes
Go to page 75
Venn Diagram: Prokaryotic and
Eukaryotic Cells
Go to diagram saved