Regulating the Cell Cycle Flashcards
Cancer
a disorder in which body cells lose the ability to control growth (There are multiple types of cancer therefore there is no specific definition/cure)
Apoptosis
programmed cell death
How many steps does apoptosis consist of
3
What are the 3 steps of apoptosis
1) Cell and its chromatin shrink
2) Parts of the cell membrane break off
3) Neighboring cells quickly clean off the cells remains
What are the reasons for apoptosis
- too many of that type of cell
- if a cell is infected or has a virus
- cell has completed its function
What are some examples that go through apoptosis
- the webbing of the digits between human digits in an embryo
- the tail of a tadpole
Normal cells display:
1) density dependent inhibition/contact inhibition
2) anchorage dependence
density dependent inhibition/contact inhibition
the idea that cells grow and divide until there is no more space left (cell membranes are touching other cell membranes) when all space is gone cells stop growing and dividing
anchorage dependence
the idea that cells need something solid to attach to to grow
tumor
mass of cells
are all tumors cancerous
no
what is this an example of ~~
when you get a wound cells at the edge of the wound divide rapidly
density dependent inhibition/contact inhibition
Benign Tumor
harmless tumor; grows divides and stops. the edges are smooth
are benign tumors cancerous
generally not
malignant tumor
bad, cancerous tumor - rough around the edges - does not stop growing and dividing - interferes with the function of other cells
metastasis
the process in which a part of the tumor breaks off, travels via blood stream to go to a different part of the body
Do benign tumors metastisize
no
How many causes for cancer are there (that we need to know)
2
What are the causes of cancer
1) Mutations
2) Carcinogens
What are carcinogens?
cancer causing agents
What are some examples of carcinogens?
- UV Light (too much)
- Debris/Chemical/Pollution
- Smoking (Nicotine)
- Hot Dogs/BBQ Meat/Deli Meats
Mutations
Incorrect order of bases in DNA
How many treatments for cancer are there
3
What are the three treatments of cancer?
1) Surgical removal
2) Radiation Therapy
3) Chemotherapy
What is radiation therapy?
gamma rays used to kill cancerous cells with their high energy
Chemotherapy
chemicals that target rapidly dividing cells - most commonly intravenous but sometimes oral
Why do people who are treated with chemotherapy sometimes loss hair or have stomach pain
Bc hair follicles and the GI tract are also rapidly dividing
Cell differentiation
the process of cells specialization - the ability to do everything going to the ability to do one specific thing
regulatory proteins
regulators that tell the cell when to divide, duplicate its chromosomes, enter another phase of the cell cycle, etc.
how many types of regulatory proteins are there
2
What are the types of regulatory proteins
internal and external
internal regulators
respond to events occurring inside a cell. Internal regulatory proteins allow the cell cycle to proceed only when certain events have occurred in the cell itself.
example of internal regulator
cyclin
How do cyclins work
1) They build from S phase to G2
2) Cyclins bond to CDK to form MPF
3) MPF allows mitosis to occur (G2 checkpoint)
4) Cdk breaks down cyclins after mitosis and after they detatch from mpf bc theyre not needed anymore + degrade (cyclin)
CDK
cyclin dependent kinases (enzymes)
MPF
maturation-promoting factor
External regulators
Proteins that respond to events outside the cell
What is one example of an external regulator
growth factors
growth factors
stimulate the growth and division of cells.
How do growth factors work
1) Growth Factor sends out signal
2) If a different cells has the proper receptor to accept the signal it picks it up and begins to divide
Do growth factors pick up their own signals
yes
What is an example of a mutation that coulf cause cancer
Proto-oncogenes → Oncogenes
Proto-oncogenes
A gene involved in normal cell growth.
Oncogene
a gene which in certain circumstances can transform a cell into a tumor cell.
Tumor-suppressor genes
regulates a cell during cell division and replication
What is an example of a tumor suppressor gene
p-53
P-53 gene
halts cell cycle until chromatin has been properly replicated.
