D103 - Lecture 21 - Cell Cycle I.docx

5 Pages
Unlock Document

Biological Sciences
Grant Mac Gregor

A. Cicker a. How to block mitosis and continue i. Inactivate cyclin-CDK complex by binding of an inhibitor B. Interphase, Mitosis, Cytokinesis a. Interphase i. G1 - growth, gap ii. S - synthesis phase iii. G2 - growth, gap b. Length of phases i. Mitosis is the shortest 1. Due to its vunerability ii. G1 is the longest phase iii. Synthesis is the longest phase (S Phase) iv. Early embryos participate in S, M B. Cell Cycle a. Commitment point b. Check Points c. Cyclin-dependent Kinase (CDK) i. Has intricinisic kinase activity ii. Kinase must be bound to CDK and bound to cyclin b. G1/S-CDK - growing. M-CDK- managing mitosis, i. Phsophorlylate mitostic actors b. Cyclin activates =kinase B. Ubiquination of cyclin to cause destruction by lysosome, every Cell cycle stage. C. S-Cdk a. Inhibitor of an inhibitor A. G0 (stationary) phase a. G0-> G1 go from in inhibitory state to a developing state B. Growth factors a. Growth factors bind to extracellular receptors b. Activate Phopoinotitol 3 kinase B. Mitogens a. Rb, binds to E2F and sequesters it from acts as transcription factor inhibitor, i. Produces b. Myc is an oncogen i. Transcription of a cyclin, activates S-Cdk b. Ras - > RTK B. Retinoblastoma a. Rb B. Checkpoints a. Regulate cell cycle transitions b. Checks for DNA damage c. Unreplicated DNA d. Spindle checkpoint i. Make sure all the chromosomes are captured correctly B. G1 Checkpoint a. DNA breakage leads to free ends of DNA i. Usually has a telomere at the end of the DNA b. P53 is the guardian of the genome i. Lost in cancer patients b. P21 i. Cdk inhibitor protein B. S-cyclin cdk a. Cdc6 i. Cell division cycle 6 ii. Genes needed for the cell cycle b. Breakdown of cdc6, not created again B. G2 Phase C. M-CDK a. Active M-Cdk i. Positive feedback 1. Activates/phosphorylates cdc25 2. Inhibits CDK-inhibitory kinase Wee1 A. Cell Cycle a. Interphase i. G1 1. slowest ii. S Phase iii. G2 b. Mitosis i. FASTest ii. Prophase iii. Metaphase iv. Anaphase v. Telophase b. Cytokinesis B. Cyclin/CDK a. Controls the cell cycle b. M-CDK i. Promotes mitosis b. S-CDK i. Initiates DNA replication b. G1/S-CDK i. Cyclin D 1. G1 to S ii. Cyclin E 1. Commits to replication (G1/S) B. CDK a. Cyclin dependent Kinase b. Active when cyclin is bound B. M-CDK a. M-cyclin i. Concentration varies during cell cycle b. CDK i. Concentration remains stable b. M-cyclin + CDK = M-CDK c. Must pass a threshold of m-Cyclin concentration d. M-CDK must be turned off before mitosis completion i. Anaphase promoting complex (APC)
More Less

Related notes for BIO SCI D103

Log In


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


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.