Biological Membranes

Fig 10-14

Lipids define space, provide barrier, act as label

What else is in biological membranes?

Proteins

What is a protein? (in general terms)

What functions do they perform?

Membrane Proteins

Transmembrane/Integral or Peripheral

What functions would require each category of membrane protein?

Cells are stable…

CBI 10.1

And yet they do this?

How?

Fluid Mosaic Model (revised)1. Length and saturation of fatty acid chains in phospholipids

More model

2. Amount of Cholesterol (and cholesterol paradox)

3. Temperature

More model 2If ‘everything can move’ is everything randomly distributed?

Lipid rafts

Tethering

Complex formation

Why is this levelof organization important for correct cellular function?

Questions?

Membranes define organelles.How?

Cell City

Coordinating the parts and the whole

Overcoming the barrier ways to cross a membrane

gated transport transmembrane transport vesicular transport

ways to signal without crossing receptors and conformational change

Case Study 1:Symptoms: One or more of the following

•Nervousness•Irritability•Rapid Heartbeat•Increased Sweating•Fine tremors of hands or feet•Sudden weight loss

What else?

Graves’ opthalmopathy

Pretibial dermopathy

Goiter

History

Cause? Unknown

Players?

Why use this case study?

Compare what should happen

with

What actually occurs

Focus on: Extracellular signalingIntracellular signalingProtein structure and function

This week in Cell Bio

Lab: Getting a feeling for the organismMating vs budding yeast what can you tell?microscopy/ platingexperimental design

Class: Extracellular signaling and cellular receptors