Class Notes (903,377)
CA (537,974)
UTSG (45,699)
BIO (2,270)
BIO120H1 (1,175)
Lecture

Tutorial notes

2 Pages
116 Views

Department
Biology
Course Code
BIO120H1
Professor
Jean Jiang Nash

This preview shows half of the first page. Sign up to view the full 2 pages of the document.
Bens Story case of retinoblastoma
Cancers result when cells lose contact with neighbours, or lose control of cell cycle, or
cannot die because of constant propagation
To combat cancer we must understand what leads to cancer at the level of molecules
Cell cycle
Enlarges, duplicates chromosomes, and separates into two cells
Must be tightly controlled with checkpoints
In yeast, decision to divide or not to divide based on nutrient availability
oIf enough, then divide
In mice, nutritional and cell-cell communication through contact and receptors
and signals that feed into cell cycle clock
oThey include tyrosine kinase receptors, G-protein coupled receptors, TGF-
beta receptors, integrins, nutrient status
oAll feed into molecular machine, used by cell to deicde whether to enter
into G0 or enter into cell cycle
oThis decision is screwed up in cancer
oWhen enter cell cycle, must finish or die
oEntering is the big decision for the cell
G0 = way for cell to exit cell cycle, if it lacks mitogen telling it to divide
Many checkpoints in cell cycle
oQuestions asked include about DNA damage (blocked if DNA damage);
replication doesnt finish if DNA damage, can stop to repair; entrance into
M, DNA must be completely replicated; anaphase blocked if chromosomes
not aligned up on metaphase plate
All are checkpoints
R point is misregulated in cancer
oMitogens gone, cell stops dividing
oBut once cell pases Restriction point, entire process is autonomous
Cell signals, mitogen, no longer matters
Once enter R point, rest of cycle must occur or die
This is checkpoint most usually lost in cancer cells
Cyclin Cdk complexes checkpoints depend on
Are protein kinases, which must be phosporylated and interact with cyclin
Cyclin binding pulls out T-loop, leaving active site of Cdk available so can
phosphorylate
Important to know are cyclin-D CDK4/6 (before R point) and cyclin-E CDK2 (after R point)
To pass R point, cell must express E, which brings cell into S-phase
CDK protein levels are stable through out cell cycle
Cyclin D expression is activated by growth factors
oRegulated by mitogens
oMitogen present, cyclin D expressed; if absent, not expressed
www.notesolution.com

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Description
Bens Story case of retinoblastoma Cancers result when cells lose contact with neighbours, or lose control of cell cycle, or cannot die because of constant propagation To combat cancer we must understand what leads to cancer at the level of molecules Cell cycle Enlarges, duplicates chromosomes, and separates into two cells Must be tightly controlled with checkpoints In yeast, decision to divide or not to divide based on nutrient availability o If enough, then divide In mice, nutritional and cell-cell communication through contact and receptors and signals that feed into cell cycle clock o They include tyrosine kinase receptors, G-protein coupled receptors, TGF- beta receptors, integrins, nutrient status o All feed into molecular machine, used by cell to deicde whether to enter into G0 or enter into cell cycle o This decision is screwed up in cancer o When enter cell cycle, must finish or die o Entering is the big decision for the cell G0 = way for cell to exit cell cycle, if it lacks mitogen telling it to divide Many checkpoints in cell cycle o Questions asked include about DNA damage (blocked if DNA damage); replic
More Less
Unlock Document


Only half of the first page are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit