Cell Biology
Outline
• Organization of body systems– Organ – Tissue – Cell—
• How do we study biology?– Why should we?
• Research question in biology
Body System Hierarchy
System > Organ > Tissue > Cell
Body System Hierarchy
Cardiovascular System
System > Organ > Tissue > Cell
Body System Hierarchy
Cardiovascular System Blood Vessel (Organ)
Vessel Tissue
System > Organ > Tissue > Cell
Cells + Matrix
Blood Vessel Tissue
The functional part of organs are cells + matrix
Matrix are proteins that hold cells together and give tissues mechanical integrity
System > Organ > Tissue > Cell
The functional part of organs are cells + matrix
Example: bone tissue
Cells Matrix
Matrix
The functional part of organs are cells + matrix
Example: bone tissue
Cells Matrix
Blood vessels
Matrix
The Cell
The Cell This is not a cell…so what is it?
50 um
~7 um
~5 um
~3 um
~100 nm
~6 um
What can cells do?
Adhesion Change Shape(Spread)
Migrate Communicate
Direction of Migration
ActinFocal Adhesion
Hey Hi
Matrix
Cell
How do we study Biology?
In vitro In vivo
Within glass Within the living
Why do we study Biology?
In vitro In vivo
If we understand why cells malfunction, we can learn how to fix them
Research Question:What role does matrix stiffness have on cells?
Cancer
Stress Shielding
1,000 Pascals1 kPa
10,000 Pascals10 kPa
50 um
50x10-6 m
50 um
50x10-6 m
Let’s look at an experiment on single cells
Substrate Stiffness Affects Cell Size
1,000 Pascals1 kPa
10,000 Pascals10 kPa
50 um
50x10-6 m
50 um
50x10-6 m
200 1000 2500 5000 100000
200400600800
100012001400
Area vs. Stiffness
Stiffness (Pa)
Are
a (u
m2)
Cell
Nucleus(DNA)
Cell Proliferation (cell division)
What’s in cells? Proteins run the showExample: Structural proteins give cells shape
What’s in cells? Proteins run the showOther proteins do lots of other things