CMMB 511 Lecture Notes - Lecture 13: Precursor Mrna, Polyadenylation, Cordycepin

9 views2 pages

rosefrog223

28 Dec 2019

School

University of Calgary

Department

Cellular, Molecular and Microbial Biology

Course

CMMB 511

Professor

Lashitew Gedamu

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

When a gene is transcribed, it first forms a primary transcript that is capped and polyadenylated, then it is spliced out to get the mature mrna. Steps in polya addition during mrna formation. In it, the expose cells to precursors (nucleotides), in addition to that they added radioactively labelled adenosine to follow addition of a nucleotide to the rna. When the gene is transcribed, see radioactivity as rna is polyadenylated. When this experiment was done, they found that only 25% of the nuclear transcripts are polyadenylated, the remaining get transcribed but are quickly degraded. Polya addition takes place in the nucleus. 1/4 of the rna modifications have polya segment. Depending on type of species, size of polya varies (mammalian cells have 250 a nucleotides added) Not all mrnas have the same number of a nucleotides, it varies slightly even though cells belong to same organism. Kinetic analysis demonstrates that the rna is labelled (nucleus) initially.

Related Questions

How can a cell remember which gene it needs to express (turn on)and which gene does from one generation to the next?

1.Methylation of cytosine bases

2.heritable chromatin structure

3.both of the above

4. none of the above

If you were to make 2 liters of a 2 molar solution of SodiumChloride (MW 58.4) How many grams of Sodium Chloride would youdissolve?

/1.58.4 /2.29.2 /3.116.8 /4.233.6

After transcription, nuclear RNA is capped, polyadenylated,spliced. After successful splicing, proteins are added to themature mRNA at the exon junction complex and then transported tothe cytoplasm. Which of the following is a NOT a reason why thesemodifications are added to

mRNA?

1.to identify the RNA molecule as mRNA

2.to stabilize mRNA molecule

3.to aid in transport from ribosome to cytoplasm throughpore

4.to signal to the cell that mRNA is ready for translation

A cell is being held in G1 phasedue to DNA damage caused by UV radiation. When the DNA is damaged,p53 is phorphorylated and precents entry into whatphase?

1.M phase 2. s-phase 3.G0 phase 4. none of the above

taupeclam801

QUESTION 1

Which of the following statements regarding splicing is FALSE?

A) The length of introns determines the efficiency of splicing.

B) Many human neurological disorders are caused by splicing errors and/or mutations in splicing factors.

C) Splicing requires the action of a variety of snRNAs that direct the transesterification reactions.

D) Splicing is dictated by sequence features in pre-mRNA transcripts

QUESTION 2

Which of the following mRNA processing factors does NOT associate with the CTD of RNA polymerase II?

A) splicing factors

B) polyadenylation factors

C) miRNAs/siRNAs

D) capping proteins

QUESTION 3

Which of the following statements about mRNA stability is FALSE?

A) Deadenylation-independent mRNA decay is exclusively in the 5' to 3' direction.

B) The most common pathway of mRNA decay is deadenylation-dependent.

C) Yeast mRNA decay occurs primarily in the 5' to 3' direction, while 3' to 5' decay is more common in mammalian cells.

D) Decapping enzymes are required for all pathways of mRNA decay.

QUESTION 4

You obtain the sequence of a gene containing 10 exons, 9 introns, and a 3â² UTR containing a polyadenylation consensus sequence. The fifth exon also contains a polyadenylation site. To test whether both polyadenylation sites are used, you isolate mRNA and find a longer transcript from muscle tissue and a shorter transcript from all other tissues. Which of the following is the most likely mechanism underlying these alternative transcripts?

A) The fifth exon is spliced out of the mature mRNA transcript in muscle cells.

B) Muscle cells have less effective polyadenylation than other tissues.

C) An alternative CPSF protein is expressed in muscle cells with lower affinity for the polyadenylation sequence in exon 5.

D) The mRNA in muscle cells is edited to eliminate the polyadenylation sequence in exon 5.

blushdonkey474

Question 1

Not yet answered

Marked out of 1.00

Flag question

Question text

The function of tRNA is to

Select one:

a. provide a site for polypeptide synthesis

b. transport amino acids to the ribosome

c. transcribe DNA

d. transform DNA

Question 2

Not yet answered

Marked out of 1.00

Flag question

Question text

The lipid bi-layer is

Select one:

a. hydrophilic

b. hydrophobic

c. hydrophilic and hydrophobic

d. depends on the surrounding medium

Question 3

Not yet answered

Marked out of 1.00

Flag question

Question text

Which of the following statements is FALSE?

Select one:

a. carbohydrates are generally hydrophilic molecules.

b. living things use carbohydrates for structure and for energy storage.

c. carbohydrates are composed principally of carbon, hydrogen, and oxygen.

d. none of the above â they are all true

Question 4

Not yet answered

Marked out of 1.00

Flag question

Question text

Which of the following terms correctly describes a compound featuring more than one double bond?

Select one:

a. saturated

b. polyunsaturated

c. monounsaturated

d. disaturated

Question 5

Not yet answered

Marked out of 1.00

Flag question

Question text

Eukaryotic mRNA transcripts are protected from modification by

Select one:

a. 5' caps

b. 5' poly-A caps

c. 3' caps

d. 5'-3' poly tails

Question 6

Not yet answered

Marked out of 1.00

Flag question

Question text

The methods of membrane transport that don't require protein channels or carriers are

Select one:

a. osmosis

b. diffusion

c. phagocytosis

d. exocytosis

e. all of the above

Question 7

Not yet answered

Marked out of 1.00

Flag question

Question text

Complete the following sentences: "Primary active transport is dependent on __________. Secondary active transport is dependent on __________ created by __________.

Select one:

a. channel proteins, electrochemical gradient, carrier proteins

b. electrochemical gradient, ATP, mitochondria

c. electrochemical gradient, ATP, primary active transport

d. ATP, electrochemical gradient, primary active transport

e. carrier proteins, electrochemical gradient, channel protein

Question 8

Not yet answered

Marked out of 1.00

Flag question

Question text

Which of the following is a reduced compound?

Select one:

a. CO2

b. O2

c. N2

d. NAD +

e. NADH

Question 9

Not yet answered

Marked out of 1.00

Flag question

Question text

Gel electrophoresis separates DNA fragments according to their:

Select one:

a. base sequence

b. size

c. percentage of labelled nucleotides

d. electrical charge

Question 10

Not yet answered

Marked out of 1.00

Flag question

Question text

G0 is:

Select one:

a. part of interphase

b. the phase of the cell cycle where DNA replication occurs

c. the phase of the cell cycle where two identical daughter cells are created

d. a special "resting" phase in which cells are in a non cycling state

e. a special phase where the number of chromosomes in a parent cell is reduced by half such that each daughter cell contains only one member of a pair of homologous chromosomes

Question 11

Not yet answered

Marked out of 1.00

Flag question

Question text

At which pH will the concentration of hydrogen ions be equal to the concentration of hydroxide ions?

Select one:

a. pH 1

b. pH 5

c. pH 7

d. pH 9

e. pH 14

Question 12

Not yet answered

Marked out of 1.00

Flag question

Question text

Which of the following enzymes has proofreading activity?

Select one:

a. Ligase

b. Helicase

c. Topoisomerase

d. DNA polymerase

e. Peptidyl transferase

Question 13

Not yet answered

Marked out of 1.00

Flag question

Question text

The process of _______________ cuts introns from the primary transcript and the final "processed" mRNA is produced.

Select one:

a. RNA cleaving

b. RNA translocation

c. RNA elongation

d. RNA splicing

Question 14

Not yet answered

Marked out of 1.00

Flag question

Question text

Transcription is initiated when RNA polymerase binds to

Select one:

a. a promoter

b. an initiator

c. a transciptor

d. a codon

Question 15

Not yet answered

Marked out of 1.00

Flag question

Question text

Complete the following sentences: "__________ connect the extracellular matrix with microfilaments. __________ connect intermediate filaments from adjacent cells."

Select one:

a. Cadherins, Integrins

b. Connexins, Cadherins

c. Integrins, Cadherins

d. Integrins, Connexins

e. Connexins, Integrins

Question 16

Not yet answered

Marked out of 1.00

Flag question

Question text

Which of the following regions of RNAs are translated?

Select one:

a. 5' UTR

b. exons

c. introns

d. 3' UTR

e. poly-A

Question 17

Not yet answered

Marked out of 1.00

Flag question

Question text

Control of gene expression in eukaryotic cells occurs at which level(s)?

Select one:

a. only the transcriptional level

b. epigenetic and transcriptional levels

c. epigenetic, transcriptional, and translational levels

d. epigenetic, transcriptional, posttranscriptional, translational, and posttranslational levels

Question 18

Not yet answered

Marked out of 1.00

Flag question

Question text

Cellular organelles containing hydrolytic enzymes are called:

Select one:

a. peroxisomes

b. lysosomes

c. ribosomes

d. mesosomes

Question 19

Not yet answered

Marked out of 1.00

Flag question

Question text

______ are chemicals or combinations of chemicals that take up excess hydrogen ions or hydroxide ions in order to keep the pH constant.

Select one:

a. acids

b. bases

c. salts

d. buffers

e. carbohydrates

Question 20

Not yet answered

Marked out of 1.00

Flag question

Question text

Which of the following proteins appear in some stages of the cell cycle and are degraded at other stages?

Select one:

a. kinases

b. cyclins

c. nucleotides

d. phosphatases

e. none of the above

Question 21

Not yet answered

Marked out of 1.00

Flag question

Question text

Which of the following correctly matches an organelle with its function?

Select one:

a. mitochondrion photosynthesis

b. nucleus cellular respiration

c. ribosome manufacture of lipids

d. lysosome movement

e. central vacuole storage

Question 22

Not yet answered

Marked out of 1.00

Flag question

Question text

What is the sequence corresponding to the following electropherogram obtained by Sanger sequencing (green: A; red:T; black: G; blue: C)?

Select one:

a. CCGTTATGAAC

b. GGCTTATGAAG

c. CAACTATTGCC

d. GGCAATAGTTG

e. CCGTTATCAAC

Question 23

Not yet answered

Marked out of 1.00

Flag question

Question text

Which of the following statement is true

Select one:

a. the two DNA strands are parallel and complementary

b. the two DNA strands are anti parallel and non-complementary

c. the two DNA strands are anti-parallel and complementary

d. none of these

Question 24

Not yet answered

Marked out of 1.00

Flag question

Question text

The energy-requiring process by which small molecules are joined to form larger molecules is specifically called

Select one:

a. metabolism

b. anabolism

c. catabolism

d. enzymatic reactions

Question 25

Not yet answered

Marked out of 1.00

Flag question

Question text

When DNA replication starts

Select one:

a. the phosphodiester bonds between the adjacent nucleotides break

b. the bonds between the nitrogen base and deoxyribose sugar break

c. the leading strand produces Okazaki fragments

d. the hydrogen bonds between the nucleotides of two strand break

Question 26

Not yet answered

Marked out of 1.00

Flag question

Question text

A(n)_______ is the movement of a segment of a chromosome from one chromosome to another nonhomologous chromosome

Select one:

a. inversion

b. translocation

c. deletion

d. duplication

Question 27

Not yet answered

Marked out of 1.00

Flag question

Question text

Complete the following sentences: "Replication forks from the same origin of replication extend __________. __________ DNA strand is used as template for the leading strand at one fork and for the lagging strand at the second fork. New DNA is synthesized from 5' to 3' on the __________."

Select one:

a. unidirectionally, A different, both the leading and lagging strands

b. bidirectionally, The same, leading strand

c. bidirectionally, The same, lagging strand

d. unidirectionally, A different, leading strand

e. bidirectionally, The same, both the leading and lagging strands

Question 28

Not yet answered

Marked out of 1.00

Flag question

Question text

Manufacturing recombinant DNA molecules involves cutting a gene from its normal location, inserting it into a circular piece of DNA from a bacterial cell, and then transferring the circle of DNA to cells of another species. Which of the below describe the circular piece of DNA?

Select one:

a. restriction enzyme

b. plasmid

c. bacteriophage

d. transposon

Question 29

Not yet answered

Marked out of 1.00

Flag question

Question text

Complete the following chemical equation to make it balanced: glycerol + ___ ? triacylglycerol + ___

Select one:

a. 3 fatty acid, 3 H2O

b. fatty acid, H2O

c. 3 OH-, 3 H+

d. 3 H2O, 3 fatty acid

e. fatty acid, 3 H2O

Question 30

Not yet answered

Marked out of 1.00

Flag question

Question text

Which structure is found in plant cells but not animal cells? Check all that apply.

Select one or more:

a. Cell wall

b. Chloroplast

c. Plastid

d. Central vacuole

e. Lysosomes

brownhound170

CMMB 511 Lecture Notes - Lecture 13: Precursor Mrna, Polyadenylation, Cordycepin

Document Summary

Get access

Related Documents

CMMB 511 Lecture Notes - Lecture 3: Community Access Program, Cistron, Exonuclease

CMMB 511 Lecture Notes - Lecture 15: Half-Life, Escherichia Coli, Cytokine

CMMB 511 Lecture Notes - Lecture 12: Small Nuclear Rna, Rna Splicing, Hbb

Related Questions