Unit 4.3-4.4 Cancer cells and regulation

 What are regulatory proteins? (4.3)

1. Proteins that regulate the health of the cell and determine whether the cell is heavy enough to divide 

   1. Cyclins - enzymes and proteins 

G1 checkpoint (4.3)

checks to make sure that the DNA is healthy and clear enough to duplicate, and to make sure it's grown enough 

G2 checkpoint (4.3)

checks to see if the DNA replicated correctly and if there is enough nutrients to divide 

Mitosis spindle fibers pause (4.3)

1. making sure that every chromosome is connected to a spindle fiber at the centromere

   1. Only pauses the cycle to make sure they all get connected 

Explain what G0 is and why a cell might enter it. (4.3)

1. G0 is a permanent phase that a cell can enter if it dont pass the checkpoints, it can't be healed

   1. Enters after the G1 checkpoint determine it's not healthy enough to continue 

2. Some stay there forever

Describe apoptosis. Why is it important that cells can undergo apoptosis? (4.3)

It is a destructive system that will destroy the cell if it has been told to stop by the checkpoints, and if it can't be fixed, therefore making it dangerous if the cell does not apoptosis because it could rapidly divide and create cancer  

Explain what may happen if the checkpoints of the cell cycle are not obeyed by the cell. (4.4)

If the cell cycle checkpoints are not obeyed and the cell is not in good shape enough to divide, then the cell will rapidly divide the bad cell configuration, ignor all signals to not divide, and cause cancer tumors. 

Differ between the genes that are often mutated in cancer cells. (4.4)

1. Protooncogenes - produces proteins that increase cell division

2. Oncogene - make cell division go into uncontrolled overdrive

3. Tumor suppressor gene - produce proteins that normally decrease cell division (causes apoptosis)

   1. If mutated, they dont stop the cell from dividing

What are 2 ways that mutations can be caused in DNA? (4.4)

1. When a cell divides with unclear DNA

2. Environmental stressors like radiation, chemo, and the sun rays

Normal cell physical characteristics

• Follow checkpoints

• Divide a finite number of times

• Go through apoptosis when errors are large

• Organized

Cancer cells Physical characteristics

• Larger nucleus

• rapidly/uncontrolled division

• Ignores apoptosis, contact inhibition ect

• Divide infinitely 

• Do not follow checkpoints

• Variation of size and shape

• Cluster of cells

Describe the functional characteristics of cancerous cells. (4.4)

1. Self-sufficiency in growth signals - make their own

2. Insensitivity to anti-growth signals - ignores it

3. Evading apoptosis - have mutations to ignore the signals

4. Limitless replicative potential - telomeres regrow, cell never dies

5. Sustained angiogenesis - release chemicals that encourage angiogenesis

6. Tissue invasion and metastasis - cancer cells travel through the bloodstream to affect other tissue

What is / are Growth factors? How does it relate to cancer?

1.  signals that tell a cell to divide 

   1. Cancer cells make their own so they never stop

What is / are Apotosis? How does it relate to cancer?

1. cell death

   1. Have mutations to ignore the genes and keep dividing 

What is / are telomeres? How does it relate to cancer?

1. ends of a chromosome that determine how many times it can divide

   1. Cancer cells replicate it and regrow it so they never die 

What is / are angiogenesis? How does it relate to cancer?

1. the growth of blood vessels that give cells nutrients and oxygen to grow

   1. Allows cancer cells to have the ability/health to grow

What is / are Metastasis? How does it relate to cancer?

1. the spread of cancer from one location to another 

   1. Allows cancer cells to infect other places