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