Log in
HomeClass Notes1,200,000CA670,000

Biology 2581B Lecture Notes - Lecture 4: Alternative Splicing, Transesterification, Phosphodiester Bond

13 views3 pages
spectral
2 May 2020
School
Western University
Department
Biology
Course
Biology 2581B
Professor
Susanne Kohalmi

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

Document Summary

Post-transcriptional gene control involves all mechanisms that regulate gene expression following transcription. This is regulated at every step of the life of an mrna (synthesis degradation). In the nucleus transcription and posttranscriptional modulation leads to the production of a mature mrna which is less prone to degradation and translocated to the cytosol. This makes it difficult to predict a mrna sequence from the dna. Pre-mrna processing is co-transcriptional, meaning that it is performed whilst another part of the. Ctd, phosphorylated by polymerase ii, recruits and activates the capping enzyme. The capping enzyme then removes a 5" phosphate from the rna and replaces it with. Gmp, thereby creating a guanosine 5" triphosphate structure. Furthermore, sr proteins can interact with exonic splicing enhancers to mediate binding of snrnas to a true splice site. Splicing of exons proceeds via two sequential transesterification reactions during each of which a phosphoester bond is exchanged for another (no energy consumed), leading to the linkage of the.

Get access

Grade+
$40 USD/m
Billed monthly
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
10 Verified Answers
Class+
$30 USD/m
Billed monthly
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
7 Verified Answers

Related Documents

Biology 2581B Chapter Notes - Chapter 7: Ribonucleotide, Phosphodiester Bond, Gene Expression
orangealligator209
Biology 2581B Lecture Notes - Lecture 16: George Gamow, Chagas Disease, Leucine
jadedolphin26
Biology 2581B Lecture Notes - Lecture 17: Rna Polymerase I, Rna Polymerase Iii, Nucleosome
scarletrabbit663

Related Questions

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 – 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