Lecture 3: Cell Growth and Ribosomes

Question 1

Cell’s ability to divide (grow in number)

Answer 1

proliferation

Question 2

cell death

Answer 2

apoptosis

Question 3

Proteins that link proliferation and apoptosis (also link cell growth to proliferation)

Answer 3

morphogens (and modulators)

Question 4

Enlargement of individual cells

Answer 4

Cellular growth

Question 5

True or false: Cellular growth equals cellular proliferation.

Answer 5

False

Question 6

What two thing do cells need to grow?

Answer 6

1) Growth factors

2) Nutrients

Question 7

Small proteins on the outside of the cell that bind to receptors and signal to the inside of the cell.

Answer 7

Growth factors

Question 8

What 4 types of nutrients do cells need to grow?

Answer 8

1) Oxygen
2) Glucose
3) Amino Acids
4) Nucleic Acids

Question 9

What links cell growth and proliferation?

Answer 9

morphogens (proteins that drive both proliferation and growth)

Question 10

Process of making proteins from RNA

Answer 10

Translation

Question 11

What is needed for translation to take place?

Answer 11

1) mRNA
2) tRNA
3) ribosomes/rRNA

Question 12

What is the rate-limiting step in protein formation (making proteins from RNA)?

Answer 12

Making ribosomes

Question 13

Where are ribosomes made?

Answer 13

Nucleolus

Question 14

What are ribosomes made from?

Answer 14

rRNA and proteins

Question 15

Which two enzymes catalyze the transcription of rDNA into rRNA?

Answer 15

Pol I and Pol III

Question 16

This enzyme catalyst makes a single RNA transcript that is turned into 3 RNAs (this occurs in the nucleolus).

Answer 16

Pol I (RNA polymerase I)

Question 17

This enzyme catalyst makes rRNA in the nucleoplasm, then brings it into the nucleus.

Answer 17

Pol III (RNA polymerase III)

Question 18

What is the part of the nucleus outside of the nucleolus?

Answer 18

nucleoplasm

Question 19

How many subunits form the ribosomal complex? What are these subunits composed of?

Answer 19

2; rRNA molecules and r-proteins

Question 20

What does the small (40s) ribosomal subunit do?

Answer 20

Reads the RNA

Question 21

What does the large (60s) ribosomal subunit do?

Answer 21

Joins amino acids to form a polypeptide chain

Question 22

True or false: rRNA is never translated (proteins are never made out of it).

Answer 22

True

Question 23

What encodes for rRNA?

Answer 23

rDNA

Question 24

True or false: rDNA has the potential to become an oncogene.

Answer 24

True

Question 25

The process of ribosome production starts in the ________ and ends in the __________.

Answer 25

Nuclolus; cytosol

Question 26

True or false: Cells can divide quickly even if they do not grow quickly.

Answer 26

False. Cells must grow quickly to divide quickly.

Question 27

What is the oncogene that functions to export the ribosome from the nucleolus to the cytosol?

Answer 27

NPM

Question 28

Where do oncogenes tend to be (upstream or downstream) in a reaction pathway? Why?

Answer 28

Upstream. Because mutations only affect processes downstream, there is no selective pressure for the development for mutations downstream.

Question 29

Which tumor suppressor halts or turns off transport, transcription, and assembly of ribosomes? Where does it reside?

Answer 29

ARF; in the nucleolus

Question 30

Where do ARF and p53 reside in the pathways of the processes they regulate?

Answer 30

Downstream.

Question 31

How much of the ATP in the cell is utilized in the production of ribosomes?

Answer 31

70%

Question 32

True or false: Growth factors have the ability to become oncogenes.

Answer 32

True

Question 33

What type of mutation is caused by centrosome amplification?

Answer 33

Intrinsic

Question 34

True or false: Cells with ATM inhibitiion can’t repair DNA.

Answer 34

True

Question 35

What enzymes carry out apoptosis?

Answer 35

Caspaces