Protein Synthesis

Question 1

______ are sites of polypeptide assembly

Answer 1

ribosomes

Question 2

the eukaryotic ribosome is composed of a ____ ____ subunit and ____ ____ subunit

Answer 2

large 60s and small 40s

Question 3

ribosomes are found either free in the _______ or associated with the _____

Answer 3

ribosomes either free in the cytoplasm or associated with the ER

Question 4

ribosomes in the ER are for protein to be

Answer 4

exported out of the cell

Question 5

three steps for the formation of mature mRNA

Answer 5

5’cap, poly A tail, splicing out introns

Question 6

translation of mRNA

Answer 6

5–>3

Question 7

the genetic code represents the relation between the

Answer 7

sequence of bases in the RNA transcripts or DNA and the sequence of aa in proteins

Question 8

three base code could specify

Answer 8

64 aa

Question 9

group of three bases

Answer 9

codons

Question 10

the amino code is

Answer 10

degenerate, more than one codon coding for it

Question 11

code is nearly

Answer 11

universal

Question 12

starts the sequence

Answer 12

methionine

Question 13

A tRNA, post-transcriptional modification include addition of ____ sequences on the ____ terminal and modification of bases at specific positions to produce _____ ____

Answer 13

A tRNA, postranscriptional modification include addition of CCA sequences on the 3’ terminal and modification of bases at specific positions to produce unusual bases

Question 14

is used to form Aminoacyl-AMP

Answer 14

ATP

Question 15

when the aminoacyl-AMP binds to tRNA it releases

Answer 15

AMP

Question 16

during the two step process of addition of aa to tRNA, once the aa is attached, “loaded” by its _________ to the _____ of the appropriate tRNA molecule by ______ ______. This is a ____ energy linkage that activates the aa.

Answer 16

loaded by its carboxyl end to the 3’end by aminoacyl-tRNA synthetase. This is a high energy linkage

Question 17

true or false: there is a different synthetase for every aa that binds to the CCA and pairs it with the correct anticodon

Answer 17

true

Question 18

relaxed bonding between the 3 base of the codon and the 5’ base of the anticodon

Answer 18

wobble hypothesis

Question 19

true or false: need multiple tRNA to recognize codons

Answer 19

false, a single tRNA to recognize a codon explaining why there are fewer tRNAs than codons

Question 20

A site

Answer 20

accomodates the incoming amino acyl tRNA

Question 21

P site

Answer 21

contains the peptidyl-tRNA complex

Question 22

E site

Answer 22

empty tRNA

Question 23

regulates the high fidelity and rate of polypeptide elongation during translation

Answer 23

eEF1

Question 24

translocation requires

Answer 24

eEF2

Question 25

stop codons

Answer 25

UAA, UAG, UGA

Question 26

monocistronic

Answer 26

Eukaryotic mRNA, only one protein is produced from an mRNA

Question 27

multiple ribosomes move along the same mRNA functioning interdependently of each other is termed a

Answer 27

polyribosome

Question 28

can have serious consequences for protein structure and function

Answer 28

mutations

Question 29

mutations at ____ ____ can lead to abnormal mRNA processing

Answer 29

mutations at splice sites can lead to abnormal mRNA processing

Question 30

when a single base substitution leads to a different aa

Answer 30

missense mutation

Question 31

loss of termination signal leading to

Answer 31

abnormally large protein

Question 32

when a mutation leads to generation of a termination signal leading to a truncated protein

Answer 32

nonsense mutation

Question 33

insertion or deletion of a number that is not divisible by 3

Answer 33

frameshift mutation

Question 34

key regulatory mechanism for translation

Answer 34

phosphorylation

Question 35

in periods of stress phosphorylation of ____ leads it to be inactive to repress translation and conserve energy

Answer 35

eIF2

Question 36

use IRES (internal ribosome entry sites) to recruit the pre-initiation complex in a manner that does not involve the ____ or initial scanning process

Answer 36

certain viruses use IRES. does not involve the Cap

Question 37

important role in regulation of translation

Answer 37

microRNAs

Question 38

21 nt long, non-coding and usually target the 3’UTR

Answer 38

miRNAs

Question 39

miRNAs recruit the _______ and either cause stalling of the ________ complex or ______ of the mRNA

Answer 39

miRNAs recruit the RISC complex and cause stalling of the translation complex or degradation of the mRNA

Question 40

tumor of the brain/spine and gene sequencing can be used to guide tx.

Answer 40

Glioblastoma

Question 41

used to determine if DNA is methylated

Answer 41

Bisulfite sequencing

Question 42

Methylation pattern of a repair gene, _____, is to guide chemo and it is only used if epigenetically silenced by ________

Answer 42

repair gene, MGMT, is to guide chemo and it is only used if epigenetically silenced by methylation

Question 43

Remdesivir in SARS-COVID-2

Answer 43

Rendesivir blocks covid RNA polymerase because it looks like ATP, and puts a stop to covid genome replication

Question 44

One therapy decision

Answer 44

Decision of whether or not to treat a given patient with chemotherapy (using temozolomide) is based on the methylation pattern of a gene (MGMT) encoding a repair protein. Chemotherapy is given if the MGMT is epigenetically silenced (methylated)