the cell cycle…gone wrong how do cells know when to divide… what controls the cell cycle…...

15

The Cell Cycle… Gone Wrong • How do cells know when to divide… • What controls the cell cycle… • Cells grown in a lab will continue to divide until they come in contact with other cells • If you scrape away some cells, they will start dividing again… • Most of the time, cells know what to do and how to do it • But how…

Upload: clemence-stephens

Post on 04-Jan-2016

219 views

Category:

Documents

3 download

Report

Download

Tags:

Embed Size (px):

TRANSCRIPT

Page 1: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

The Cell Cycle…Gone Wrong

• How do cells know when to divide…• What controls the cell cycle…• Cells grown in a lab will continue to divide until

they come in contact with other cells• If you scrape away some cells, they will start

dividing again…• Most of the time, cells know

what to do and how to do it• But how…

Page 2: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

10.3 Regulating the Cell Cycle

• Cyclins – a family of proteins that help regulate the cell cycle

• Internal regulatory proteins – proteins inside a cell– Make sure everything is timed properly– Cells don’t enter mitosis until AFTER DNA is replicated

• External regulatory proteins – respond to events outside a cell– Heal wounds; tell cells when to stop dividing– What if cells kept going and going and going…

Page 3: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

Cell Death

• Cells are “born” in the cell cycle, and therefore must “die”• Happen by accident or injury, or…• Programmed to die = Apoptosis• Apoptosis is like self-destruction mode• Cell and DNA shrinks, parts break off, and neighboring cells

clean up the remains• Key role in embryonic development

Page 4: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

Uncontrolled Cell Growth• If cells grow out of control, cancer results• Cancer – inability to control cell growth• Cancer cells do not respond to signals

that regulate most cells, and will divide out of control

• A mass of cancerous cells = Tumor• Benign tumors – do not spread• Malignant tumors – spread through

body

Page 5: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

What causes cancer?

• Gene defects that regulate cell growth and division– Defect of gene called p53 is most common

• Smoking or chewing tobacco• Radiation exposure (X rays, UV rays)• Even viral infection• Common factor = can’t control cell cycle

Page 6: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

Treatments for Cancer• Removal• Radiation – target a specific

area of the body• Chemotherapy – chemical

compound that kills cancer cells (it targets cells that grow rapidly, so it kills healthy cells sometimes too)– Serious side effects

Page 7: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

• In which phase does the nuclear envelope break down?

Page 8: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

• In which phase do chromosomes line up at the middle?

Page 9: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

• In which phase is DNA replicated?

Page 10: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

• In which phase are chomatids pulled apart?

Page 11: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

• In which phase does the nuclear envelope reform?

Page 12: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

• What is the final product?

Page 13: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

During the videos, consider…• How is the cell cycle different in plants

compared to animal cells?

• How does cell division benefit us?

• How can the cell cycle cause us harm?

Page 14: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

What is cancer, exactly?• Cancer is what occurs when the cell cycle gets

out of control and cells don’t die when they’re supposed to

• What causes cancer?• Can we cure cancer?

Page 15: The Cell Cycle…Gone Wrong How do cells know when to divide… What controls the cell cycle… Cells grown in a lab will continue to divide until they come

• http://www.youtube.com/watch?v=3kpR5RSJ7SA

• Does your cell cycle drawing match these descriptions?

• http://www.youtube.com/watch?v=Q9cuEYSt0GE&feature=related

http://www.youtube.com/watch?v=3kpR5RSJ7SA

http://www.youtube.com/watch?v=3kpR5RSJ7SA

http://www.youtube.com/watch?v=Q9cuEYSt0GE&feature=related

http://www.youtube.com/watch?v=Q9cuEYSt0GE&feature=related

Cell Division The Cell Cycle and Mitosis. Why do cells divide? Growth Reproduction Repair

Why do cells divide?. Cells divide to maintain a workable volume to surface area ratio

The Cell Cycle, Mitosis, and Meiosis New cells can only be made when existing cells divide. All cells have the ability to divide – but some cells lose

How Cells Divide Mitosis is a key phase of the cell cycle Phases of the Cell Cycle

The Cell Cycle. Why do cells divide? - Smaller cells are more efficient at: - Obtaining: O2O2 H2OH2O Nutrients (glucose amino acids, etc.) - Ridding themselves

The Cell Cycle: Cell Division and Mitosis How and Why Cells Divide

The Cell Cycle 5A How eukaryotic cells divide to make new cells

Why do cells divide?. The Cell Cycle Why do cells divide? Repair Growth Reproduction Some organisms reproduce by cell division (asexual) Limit on size

Mitosis and Asexual Reproduction. I.The Cell Cycle A.Why Cells Divide... 1.cells obtain most resources through diffusion a.diffusion = FAST small distances

REGULATING the CELL CYCLE. CELL DIVISION GENES Some cells divide frequently (some human skin cells divide once/hour) Some cells divide occasionally (liver

How Do Cells Divide?. What you will learn… 1. Why Do Cells Divide? 2. Chromosome structure 3. Cell Division in Prokaryotes 4. Cell Cycle 5

Why do Cells Divide? Why do Cells Divide? Cell Size Limits

I. I.Control of Cell Cycle Normal growth & development require control of cell cycle (timing, location) Some cells divide frequently (Ex: Skin cells) Some

THE CELL CYCLE. Why do cells divide? Stimuli to start a cell division: – To replace dead or dying cells, –To produce more cells to enlarge the organism

Topic 1.2 Why do animal cells divide and what happens … · 28/09/2009 · cell cycle interphase mitosis ... anaphase telophase Why do animal cells divide and what happens when they

10-3: Regulating the cell cycle. Cardiac cells Small intestine Smooth muscle Nerve cell: brain Cardiac: cannot divide Smooth muscle: can divide Intestine:

The Cell Cycle Chapter 12. When do cells divide? Reproduction Replacement of damaged cells Growth of new cells In replacement and growth cell

The Cell Cycle the amazing! incredible! I-can’t –wait-to- hear-more story of how cells divide

Regulating the Cell Cycle. Some cells divide every few hours (skin and digestive tract cells) Some cells never divide (muscle and nerve cells)

Cell Division The Cell Cycle and Mitosis. Why do cells divide? Growth Repair Reproduction

THE CELL CYCLE As eukaryotic cells grow and divide, they move through three distinct stages: 1.interphase – cells grow and prepare to divideinterphase

Chapter 12: The Cell Cycle (How do cells divide?) - Auburn … · · 2014-09-25Chapter 12: The Cell Cycle (How do cells divide?) cell division in prokaryotes chromosomes eukaryotic

Cell Cycle, Mitosis, and Meiosis. Why do cells divide? Most cells go through a series of changes in order to maintain homeostasis. Cells need to reproduce

Chapter 12: The Cell Cycle (How do cells divide?)

The Cell Cycle and Mitosis. What is Mitosis? Mitosis is the process by which eukaryotic cells divide. Prokaryotes divide through a simpler process called

The Cell Cycle Chapter 12 Cells have to divide in order to multiply

1 The Cell Cycle and How Cells Divide. 2 Phases of the Cell Cycle The cell cycle consists of – Interphase – normal cell activity – The mitotic phase –

CHAPTER 12 THE CELL CYCLE · 3 Division is differ among cells:. -Skin cells divide frequently.-Liver cells divide when needed (damage repair).-Nerve cells and muscle cells do not

Cell Cycle: Life Events of a Cell Interphase: -period of cell growth and function -cells that never divide are in G 0 forever If a cells prepares to divide:

The Cell Cycle. When do cells divide? Reproduction Replacement of damaged cells Growth of new cells In replacement and growth cell divisions how should

Ways Cells Divide. Bacterial Cell Division Bacteria divide by binary fission –No sexual life cycle –Reproduction is clonal (no variation in offspring)

Chapter 12: The Cell Cycle (How do cells divide?) cell division in prokaryotes cell division in prokaryotes chromosomes chromosomes eukaryotic cell cycle

The Cell Cycle Chapter 10, Section 2. Why do cells divide? §For growth, repair, and reproduction

CELL CYCLE How Do Cells Divide?. What you will learn… 1. Why Do Cells Divide? 2. Chromosome structure 3. Cell Division in Prokaryotes 4. Cell

How Cells Divide Chapter 10. 2 Bacterial Cell Division Bacteria divide by binary fission –No sexual life cycle –Reproduction is clonal Single, circular