Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


AP Bio- Cell Cycle 2: Cell Cycle Control

2 of 4 of my cell cycle unit. Image Credits: Biology (Campbell) 9th edition, copyright Pearson 2011, & The Internet. Provided under the terms of a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. By David Knuffke.

Jessica Gregerson

on 26 January 2015

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of AP Bio- Cell Cycle 2: Cell Cycle Control

Cell Cycle Control
Big Questions:
Make Sure You Can:
Describe how cells determine whether or not to divide.

Explain the mechanics of the cell cycle control mechanisms described in this presentation

Explain how cancer develops.

Compare the roll that proto-oncogenes and tumor suppressor genes play in controlling the cell cycle.

Explain how cancer treatments work (and why they are not great for the body).
How is cell division controlled?

Why do people get cancer?
Cells should only divide when they need to.
The cell cycle is under both internal and external control
It's best to think of the cell cycle as consisting of a series of "
" that the cell must pass through in order to be able to divide.

What happens if cells don't pass a checkpoint?
The G1 checkpoint:
A breast cancer cell
Internal Controls:
External Controls:
Protein molecules that are present in varying concentrations during the cell cycle
Proteins and other environmental signals generated by other cells
Evidence suggesting that there are molecules present during the cell cycle that cause cells to progress
Determines if a cell should replicate its DNA.

From here cells either enter S phase or G0

"Senescence": Cells that have stopped dividing
MPF: Mitosis Promotion Factor
Cdk: "Cyclin-dependent" kinase
Present in a constant amount
Cyclin: the Cdk "on switch"
made in an increasing amount as the cell moves through interphase
MPF: Cyclin + Cdk
turns on other proteins needed for mitosis (e.g. microtuble formation)
No Cyclin = No Mitosis

What kind of feedback is this?
PDGF: Platelet Derived Growth Factor
What are platelets? Why do they make a growth factor?
Positional Inhibition
Normal animal cells must be anchored and not too crowded ("density-dependent").
Cancerous cells don't care
Uncontrolled Cell Division
Mutations Happen!
Every second of every day, your DNA is beset by entropic forces.
You have a whole series of genes that make sure mutated cells don't divide.
...but what happens when these genes get mutaed?
stimulate cell division
"The accelerator"
Oncogenes: mutated versions. Always "on".
Tumor Suppressor Genes
inhibit cell division
"The brake pedal"
mutated versions always "off".
Cancer requires ~6* mutations in different genes (it's a "multi-step" pathway)
The Stages of Cancer
* The "Knudson hypothesis" Suggested by Carl Nordling, based on the fact that cancer occurs on average as a sixth function of an individual's age. Who says math is useless?
A multistep model of colon cancer development
Metastasis is what kills people.

How do we treat cancer?
Is all the DNA copied correctly?

What if it's not?

Metaphase Checkpoint:
Are all chromosomes attached to a spindle

What if they are not?
The G2 checkpoint:
Watch this and then cruise through the rest of the Prezi!
Note: Yes, this is the SAME video as in the last Prezi. Watch the section about
cell cycle controls
for this Prezi!!
Bozeman Science
Full transcript