BIO230H1 Lecture Notes - Lecture 6: Start Codon, Transcriptome, Quality Control

45 views10 pages

cerisetoad631

4 Nov 2016

School

Department

Course

Professor

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

avalack09 and 39882 others unlocked

BIO230H1 Full Course Notes

Verified Note

42 documents

Document Summary

Readings (alberts et al. , custom text) pages 72-82; 122-129. Eukaryotic rna processing initiated before transcription is completed. Any defect mrna will produce aberrant proteins -> damage cells mrna quality control in the cytosol. Some mrnas are incompletely processed or damaged in the cytosol. Need to prevent production of aberrant protein which can be toxic to cells. Trnas match amino acids to codons (3 nucleotides) in the mrna. Start codon - methionine aug on rna atg on dna. Mrna message is decoded in ribosome made up of >50 different proteins and several rna molecules. Amino acids are added to the c-terminal end of the growing polypeptide chain. Therefore proteins are synthesized from n- to c- terminus. 5" end = n term of the translated protein mrna quality control in the cytosol - eukaryotes. Translation initiation machinery recognizes 5"-cap and poly-a tail. Eukaryotic initiation factors (eifs) (bind only to properly processed mrna)

Related Questions

If one is testing a goodness of fit to a 9:3:3:1 ratio, how many degrees of freedom would be associated with the Chi-square?

not enough information to determine

Which of the following choices does not describe a type of posttranslational modification of proteins?

The amino terminal methionine may be removed.

Glycoproteins are produced by the attachment of phosphates to newly synthesized proteins.

Precursor proteins are cleaved and trimmed by protease enzymes to produce a functional protein.

Molecular chaperones help proteins fold correctly.

Amino acids in the amino terminal of the protein can be acetylated.

A eukaryotic DNA sequence that affects transcription at distant promoters is called a(n)

long distance promotor

regulator

operon

enhancer

DNA methylation may be a significant mode of genetic regulation in eukaryotes. Meythylation refers to

altering RNA polymerase activity by adding methyl-groups

changes in DNA-DNA hydrogen bonding

altering translation activity via methylated tRNAs

adding methyl groups to certain cytosines in DNA

If a nucleotide lacks a 3â-OH group, what will happen?

itâs transformed into RNA

another nucleotide can bond at the 3â site during replication

replication will halt

no effect

Which of the following describe posttranscriptional modifications commonly seen in mRNA of eukaryotes?

5â capping, 3â-poly-A tail addition, splicing

3â capping, 5â poly-A tail addition, splicing

heteroduplex formation

5â capping, 3âpolyA tail addition, removal of exons

In birds, females are the heterogametic sex. This means that

females have chromosomes in pairs.

emales produce eggs.

females determine the gender of their offspring.

males have two identical sex chromosomes (ZZ)

An anticodon on a tRNA has the sequence 5'âGCAâ3'. What would be the effect on translation if the G in the anticodon were mutated to a U?

The anticodon could pair to the serine codon 5'âUCAâ3', and a cysteine would be incorporated at all points where a serine should have been incorporated.

The anticodon could pair to the threonine codon 5'âACUâ3', and a threonine would be incorporated at all points where a cysteine should have been incorporated.

The anticodon could pair to the serine codon 5'âAGUâ3', and a serine would be incorporated at all points where a cysteine should have been incorporated.

The anticodon could pair to the stop codon 5'âUGAâ3', and instead of stopping translation, a cysteine would be incorporated and translation could continue.

1. You have the following prokaryotic DNA sequence: 5â²-GGACTAGACAATAGGGACCTAGAGATTCCGAAA-3â² 3â²-CCTGATCTGTTATCCCTGGATCTCTAAGGCTTT-5â² If the top strand is the template strand which sequence below is the correct mRNA transcript? A. 5â²-GGACUAGACAAUAGGGACCUAGAGAUUCCGAAAâ3â² B. 5'-UUUCGGAAUCUCUAGGUCCCUAUUGUCUAGUCC-3' C. 5'-CCUGAUCUGUUAUCCCUGGAUCUCUAAGGCUUU-3' D. None of the above are correct

2.Starting in the cytoplasm with a fully mature mRNA explain the process of translation initiation and then elongation and termination to me.

3.Prior to export from the nucleus, pre-mRNA must be processed. What specifically does this entail?

4.The biosynthetic pathway for the two amino acids E and H is shown schematically in the figure. You are able to show experimentally that E inhibits enzyme V, and H inhibits enzyme X. The most logical hypothesis regarding the regulation of Enzyme T would be that it is most likely subject to feedback inhibition by E alone. True or False?

5. A. kinase B. ligase C. polymerase D. oxido-reductase E. Phosphatase F. protease G. nuclease H. ATPase 1. Removes a phosphate group from a molecule 2. Hydrolyzes ATP 3. Hydrolyzes bonds between nucleotides 4. Adds phosphate groups to molecules 5. Catalyzes reactions in which one molecule is oxidized and another is reduced 6. Hydrolyzes peptide bonds 7. Joins two ends of DNA together 8. Catalyzes the synthesis of polymers such as RNA and DNA

6. Looking at the figure showing the change in reaction rate for two different enzymes that both utilize the same substrate, answer the following questions. a. What is the approximate Vmax for enzyme B ? b. What is the approximate Vmax for enzyme A ? c. What is the approximate Km for the enzyme which has a higher affinity for the substrate uM.

7. Answer the following question either yes or no (spell out the word, do not abbreviate as y or n). Looking at the following coupled reaction: Luciferase luciferin + O 2 ==========> oxyluciferin + light âG = + + Mg2+ ATP <=> AMP + PPi âG = - - - a. Based on your knowledge of free energy change and reactions would this coupled reaction occur ? b. Would changing the second step from ATP<=> AMP + PPi âG = - - - to ATP <=> ADP + Pi âG = - change your answer

7.Spontaneous reactions by definition will happen instantaneously. Why false?

8. Each of the following questions apply to the image of the channel protein. The purple sphere is a charged ion. Type your response to each question in the blank provided. a. Based you on what you know about cells and ions, what does the tri-lobed red and white molecule represent (although there aren't anywhere near enough of them shown) ? b. Since the question stated the purple sphere was a charged particle, using what you know about the tri-lobed red and white molecule what is the charge of the purples sphere c. On the extracellular space, on the right side of the purple sphere, there are two tri-lobed red and white molecules in close proximity to one another. The red of one appears to be attracted to the white of the other. What type of bond is this ? d. Based on your knowledge of proteins that interact with the membrane and the properties of the membrane, to what family of amino acids would the amino acid marked by A. most likely belong? ?

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

BIO230H1 Lecture Notes - Lecture 6: Start Codon, Transcriptome, Quality Control

BIO230H1 Full Course Notes

Document Summary

Get access

Related textbook solutions

Molecular Cell Biology

Biology: Science for Life with Physiology

Biology

Concepts of Biology

Essentials of Biology

Related Documents

BIO230H1 Lecture Notes - Lecture 6: Nuclear Pore, Aconitase, Critical Role

BIO230H1 Lecture Notes - Lecture 6: Chromatin, Aconitase, Dicer

BIO230H1 Lecture Notes - Lecture 6: Exon Junction Complex, Start Codon, Polyadenylation

Related Questions