Transcript PPoint Lec 1

WELCOME TO CELL PHYSIOLOGY
What is cell
physiologyand how does it
differ from
cell biology??
Some themes repeated throughout the course…
CompartmentalizationThere is an inside and an
outside to thingsand cells make energy, use
energy, and defend
themselves by taking
advantage of this
Statistical ProbabilityThings happen in the cell when
particles bump into each othercells cheat by making it more or
less likely they will bump into
each other to speed things up
or slow them down
•enzymes
•nerve transmission
Unitary StructureThings are put together
by linking components,
and components are
constantly recycled
Division of Labormolecules, proteins, cells,
tissues, systems have specialized
functions to do specific jobs-but
may also play several roles
simultaneously
•glutamate as amino acid and
neurotransmitter
•leptin in adiposity, sexual
development, immunity,
angiogenesis, etc.
Cells have a historyCells do what they do because that
is how they evolved-not necessarily
because it is the most efficient
way to do things
Most of what I tell you will not be true within 5 yearssome won’t be true for more than a few weeks!
-Cell physiology is arguably the most rapidly advancing
field in science-with thousands of articles published each
week (in my own field of leptin-over 4500 papers published
since 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already out of date.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 processthis 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 protein
that will be stabilized by damaged DNA. It then starts
a cascade that will prevent the cell from dividing (and in
some 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 cancer
p53+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 premature
aging)
The mutant mice also ‘look old’
Wild Type
Mutants