Lecture 10

Question 1

What does transcription do?

Answer 1

makes an RNA copy of DNA

Question 2

What RNA transcribes most rRNA genes?

Answer 2

RNA polymerase 1

Question 3

What RNA polymerase transcribes all protein-coding genes, miRNA genes, plus genes for other noncoding RNA’s?

Answer 3

RNA polymerase 11

Question 4

What RNA polymerase codes tRNA genes, 5s rRNA genes and genes for many other small RNA’s?

Answer 4

RNA polymerase 111

Question 5

What form of rna carries amino acids for translation?

Answer 5

tRNA

Question 6

What rna codes for proteins?

Answer 6

mRNA

Question 7

What rna is involved in gene expression?

Answer 7

micro RNA

Question 8

What rna form the core of the ribosome’s structure and catalyze protein synthesis

Answer 8

Ribosomal RNA

Question 9

Can RNA act as an enzyme (ribozyme), catalyzing chemical reactions?

Answer 9

yes

Question 10

What initiates transcription to happen?

Answer 10

promoter

Question 11

What is the TATA box?

Answer 11

is contained in the promoter and recruits general transcription factors

Question 12

What is the role of the general transcription factors?

Answer 12

Seperate the double stranded DNA, allowing RNA polymerase II access to the template strand

Question 13

What is it called when removing an intron?

Answer 13

splicing

Question 14

What is the region called that has been spliced

Answer 14

splicesome

Question 15

What does it mean when the mRNA is capped, polyadenylated, and spliced?

Answer 15

Ready for export out of the nucleus

Question 16

What happens during translation?

Answer 16

Translation decodes the mRNA and producing the corresponding protein

Question 17

What does translation require?

Answer 17

mRNA
Ribosome
aminoacytl-tRNA

Question 18

What is the largest and abundant protein complexes in cells?

Answer 18

Ribosome

Question 19

What type of RNA does ribosomes have?

Answer 19

rRNA

Question 20

What links the proper amino acid to the corresponding tRNA?

Answer 20

tRNA synthase

Question 21

What enzyme is highly specific?

Answer 21

tRNA synthase

Question 22

what happens at the A site?

Answer 22

first binding site for aminoacyl-tRNA

Question 23

What happens in the P site?

Answer 23

tRNA linked to the polypeptide

Question 24

What happens at the E site?

Answer 24

Exit site for the tRNA

Question 25

What is the mRNA ribosome complex called?

Answer 25

polysomes

Question 26

What does polysome analysis indicate?

Answer 26

Translation activity of cells

Question 27

What end of the protein starts folding as soon as it emerges from the ribosome?

Answer 27

N -terminal

Question 28

Cotranslational folding of proteins only occurs to what type of proteins?

Answer 28

less complex proteins

Question 29

What is the role of a molecular chaperone?

Answer 29

Help with protein folding

Question 30

What do chaperones require?

Answer 30

ATP

Question 31

What is the endoplasmic reticulum functions?

Answer 31

- protein translocation - protein folding - protein glycoslytion - protein quality control - calcium iron storage

Question 32

What is the structure of the ER?

Answer 32

Membrane network, distributed by microtubule interactions

Question 33

What materials are translated at the ER?

Answer 33

Transmembrane proteins and soluble lumenal proteins

Question 34

What ensures proper insertion into the membrane or delivery into the lumen of the ER?

Answer 34

Ribosome linkage with protein translocator

Question 35

What is the n terminus?

Answer 35

lumenal

Question 36

What is the C - terminus?

Answer 36

cytosol

Question 37

Where are the n and c termini located?

Answer 37

cytoplasm

Question 38

What happens during N-linked glycosylation?

Answer 38

Modification of an amino group

Question 39

What happens in o-linked glycosylation?

Answer 39

Modification of OH group

Question 40

Most proteins that are translated and translocated at the ER become what?

Answer 40

glycosylated (both soluble and transmembrane proteins)

Question 41

What does glycosylation increase?

Answer 41

Increase stability of secreted proteins

Question 42

Why is the glycosylation of surface proteins important?

Answer 42

Important for recognition of self vs foreign (immune system)

Question 43

Where do newly synthesized proteins fold?

Answer 43

In the ER

Question 44

What is allowed to leave the ER?

Answer 44

Only folded proteins - unfolded proteins remain in the ER with chaperones

Question 45

What happens to proteins that are not properly fold in to the ER?

Answer 45

They are retro translocated to the cytoplasm, ubiquitinated and degraded by the proteasome

Question 46

What is retrotranslocation mediated by?

Answer 46

By the same translocator protein that allows for protein import into the ER