WELCOME TO CELL PHYSIOLOGY

What is cell physiology-and how does it differ fromcell biology??

Some themes repeated throughout the course…

Compartmentalization-There is an inside and an outside to things-and cells make energy, use energy, and defend themselves by taking advantage of this

Statistical Probability-Things happen in the cell when particles bump into each other-cells cheat by making it more or less likely they will bump intoeach other to speed things up or slow them down•enzymes•nerve transmission

Unitary Structure-Things are put togetherby linking components,and components areconstantly recycled

Division of Labor-molecules, proteins, cells,tissues, systems have specializedfunctions to do specific jobs-butmay also play several roles simultaneously•glutamate as amino acid and neurotransmitter•leptin in adiposity, sexual development, immunity,angiogenesis, etc.

Cells have a history-Cells do what they do because thatis how they evolved-not necessarilybecause it is the most efficientway to do things

Most of what I tell you will not be true within 5 years-

some won’t be true for more than a few weeks!

-Cell physiology is arguably the most rapidly advancingfield in science-with thousands of articles published eachweek (in my own field of leptin-over 4500 papers publishedsince mid 1994).So…your book, although it has a publication date of 2000-is already out of date.

We will supplement your book with brand-spanking new data.

Why bother???

Science is a process-and it is very useful to know the process-this course will give you the tools to understand (at some level)any paper in cell physiology-and that is very useful!

A Cool Cell Physiology Story to get you started…

p53 is a tumor suppressor gene, that codes for a proteinthat will be stabilized by damaged DNA. It then startsa cascade that will prevent the cell from dividing (and insome cases subsequently kill the cell)Fig. 13-36 p. 532

Why not make LOTS OF p53 all the time?

Tyner et al., (Nature 415: 45-53; 2002) 15 authors!

Made a mutant mouse that makes lots of p53-all the time. Is it resistant to getting tumors?

p53 ++ (wild type) median lifespan of 118 weeks, max 164 weeks,>45% of individuals get cancerp53+m (mutant) median lifespan of 96 weeks, max 136 weeks,<6% of individuals get cancer

Mutant mice age

prematurely, with lordokyphosis (hunched back), loss of weight, and degradation of ability to make RBCs.

Mutant mice also can’t grow hair well (consistent with prematureaging)

The mutant mice also ‘look old’

Wild Type

Mutants