Unit 2 - Cell Signaling

Question 1

How do Cells send and receive signals?

Answer 1

Through signal transduction

Question 2

What process occurs as an organism develops?

Answer 2

Rapid Cell Division and then diffrentiation

Question 3

What are Mature Cells?

Answer 3

A cell which has acquired a specific function rather than general.

Question 4

What are tissues in the body made from?

Answer 4

cells that interact with each other forming functional organs

Question 5

What is a plasma membrane?

Answer 5

The barrier from outside and inside the cell

Question 6

What is a nucleus

Answer 6

The internal complex which contains all of the genetic material

Question 7

What are receptors?

Answer 7

Imbedded in the cells membrane, which receive signals

Question 8

Why do cells have all the same DNA information in the nucleus, but all express differently?

Answer 8

Transcription factors can either turn certain genes on and off, the ones that are turned on are the ones that can be expressed in the cell

Question 9

Do human cells have a high lifespan?

Answer 9

Yes, only ~1% actually go through mitosis

Question 10

What are Embryonic cells?

Answer 10

Cell which is derived from an early stage of an embryo, which is able to differentiate.

Question 11

How are embryonic cells produced?

Answer 11

Through cell division of Embryonic stem cells

Question 12

What are Embryonic cells able to produce?

Answer 12

Adult cell types which are totipotent
–> they can differentiate into any adult cell

Question 13

What is the difference between Adult cells and Embryonic cells

Answer 13

Embryonic cells can differentiate into type of cell type (liver, skin, eye, etc. )
==> totopotent

Adult cells can only differentiate into the cells within its tissue
==> pluripotent

Question 14

How do Stem cells know when to replicate and what to replicate to?

Answer 14

Through a signal, and then the transduction pathway is initiated

Question 15

What are stem cells?

Answer 15

The set of cells that are able to amplify/copy together and turn into different specialized cells

They differentiate

Question 16

What is self renewal

Answer 16

A process stem cells go through in cell division

• When the stem cell goes through mitosis, one goes and differentiates and the other remains the stem cell

Question 17

When does the cell get told to differentiate

Answer 17

After its parent cell went through mitosis, and its only told to that one cell

Question 18

Will cells divide again when they are mature?

Answer 18

No, its very rare

Question 19

What happens to the mature cells after a while?

Answer 19

they die off

Question 20

How are the mature cells replaced?

Answer 20

through other stem cells going through differentiation and replacing them.

Question 21

What is the process of cell signaling?

Answer 21

Receptor activation, signal transduction, response, termination

Question 22

What is protein Kinase?

Answer 22

It is an enzyme which starts phosphorylation, activates protein target

Question 23

What is the Kinase and Phosphatase rule in this class?

Answer 23

Phosphatase always wins

Question 23

What is protein turnover

Answer 23

The idea that after cell life, it dies and it is re-expressed if the nucleus codes for it

Question 24

What is Ubiquitin Dependent Proteolysis

Answer 24

The same idea of protein turnover

Ubiquitin is selectively attached to proteins

Tag tells it to go to protesome

protein is destroyed and ubiquitin is recycled

Question 25

What is Receptor Mediated Endocytosis

Answer 25

When receptor is stuck in membrane and signal enters the receptor

Signal is collected as a vesicle and the two are separated

Divides into two vesicle, one has receptor and one has vesicle

Receptor is then entered back into the membrane

OR

Destroyed if signal no longer needed

signal is ALWAYS degraded in lysosome.

Question 26

Degradation mode

Answer 26

Receptors are removed and the signal is destructed in the lysosome

Question 27

Recycle Mode

Answer 27

the receptors are replaced without signal m
- the signal is destructed in the lysosome