Biology 1002B Chapter 14.2: Cycle 8 - Regulation of Transcription in Eukaryotes

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amethystarmadillo903

3 May 2018

School

Western University

Department

Biology

Course

Biology 1002B

Professor

Tom Haffie Denis Maxwell

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Two general categories of eukaryotic gene regulation

• Short-term - regulatory events in which gene sets are quickly turned on or off in response

to changes in environment; similar to prokaryotic gene regulation

• Long-term - regulatory events required for an organism to develop and differentiate;

occurs in multicellular eukaryotes

14.2a In Eukaryotes, Regulation of Gene Expression Occurs at Several Levels

Regulation of gene expression is more complicated in eukaryotes because they are more

complex

• Eukaryotic nuclear envelope separates transcription and translation

• Gene expression regulated at transcriptional, post-transcriptional, translational, and post-

translational level

• Most important is transcriptional regulation

14.2b Regulation of Transcription Initiation

• Organization of a eukaryotic protein-coding gene

o Promoter

• Contains TATA box, which is a regulatory DNA sequence that plays a role in

transcription initiation

• RNA polymerase II cannot recognize promoter sequence - transcription

factors recognize TATA box and then recruit the polymerase

o Promoter proximal region

• Contains promoter proximal elements (regulatory sequence)

• Regulatory proteins bind to promoter proximal elements to stimulate or

inhibit rate of transcription

o Enhancer

• Region at a significant distance from beginning of a gene containing regulatory

sequences that determine whether the gene is transcribed at max rate

• Regulatory proteins also bind with enhancer to stimulate or inhibit rate of

transcription

• Activation of transcription

o General transcription factors bind to TATA box which recruits RNA polymerase II

o Transcription factors and RNA polymerase II forms transcription initiation complex

o On its own, this complex brings about a LOW rate of transcription initiation, leading

to few mRNA transcripts

o Activators: regulatory proteins that play a role in positive regulatory system to

control expression of one or more genes

• Activators bind to promoter proximal elements and stimulate transcription

initiation by interacting with transcription factors at promoter

• Housekeeping genes have promoter proximal elements that are recognized by

activators present in all cell types

• Genes expressed in only particular cell types have promoter proximal

elements that are recognized by activators found only in those cell types

o Motifs: highly specialized region of protein produced by 3D arrangement of AA; give

rise to functional properties of activators

• Helix-turn-helix - one alpha-helix binds to base pairs in DNA, then a looped

(turn) region of the protein connects a second alpha-helix and holds first helix

in place

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Document Summary

Short-term - regulatory events in which gene sets are quickly turned on or off in response to changes in environment; similar to prokaryotic gene regulation. Long-term - regulatory events required for an organism to develop and differentiate; occurs in multicellular eukaryotes. 14. 2a in eukaryotes, regulation of gene expression occurs at several levels. Regulation of gene expression is more complicated in eukaryotes because they are more complex: eukaryotic nuclear envelope separates transcription and translation, gene expression regulated at transcriptional, post-transcriptional, translational, and post- translational level, most important is transcriptional regulation. Zing finger - resembles finger projecting from a protein and presence of a bound zinc atom. Steroid binds to its receptor in cytoplasm and activates the receptor: hormone-receptor complex enters nucleus and binds to steroid hormone response element (regulatory sequence) adjacent to the gene whose expression is controlled by the hormone.

Related Questions

1 DNA sequences found in introns provide [A] amino acid sequence information.

[B] regulatory information.
[C] no known useful information.

[D] structure for the gene.
[E] alternative DNA splicing possibilities.

3. The TATA box is a(n)
[A] sequence close to the promoter region of many genes.
[B] square-shaped sequence.
[C] enhancer consensus sequence.
[D] activator sequence necessary for proper translation.
[E] None of the above

5. Regarding genes and gene expression, which of the following is not a difference between prokaryotes and eukaryotes
[A] Eukaryotic DNA does not contain a TATA box close to the initiation site as does prokaryotic DNA.

[B] In eukaryotes, RNA polymerase requires

'transcription factors'or initiation.

[C] Prokaryotic genes are often grouped together in

operons.

[D] In eukaryotes, the regulation of several genes at once requires common control elements in each of the genes.
[E] There is a diversity of eukaryotic polymerases that is reflected in the diversity of eukaryotic promoters.

10) In eukaryotic cells, a repressor

[A] is made of DNA.
[B] binds to the enhancer region to block transcription. [

C] is located both upstream and downstream from the promoter.
[D] binds to the operator to block RNA polymerase.

[E] binds to a silencer to reduce transcription rates.

Coordinated regulation of genes in eukaryotic cells [A] is the result of positioning the same regulatory sequence in front of each gene.
[B] results from all of those genes being under the control of one promoter.

[C] occurs because related genes all have the same

operons.
[D] occurs because enhancers cause DNA to bend.

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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

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The lipid bi-layer is

Select one:

a. hydrophilic

b. hydrophobic

c. hydrophilic and hydrophobic

d. depends on the surrounding medium

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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

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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

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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

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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

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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

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Which of the following is a reduced compound?

Select one:

a. CO2

b. O2

c. N2

d. NAD +

e. NADH

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Gel electrophoresis separates DNA fragments according to their:

Select one:

a. base sequence

b. size

c. percentage of labelled nucleotides

d. electrical charge

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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

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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

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Which of the following enzymes has proofreading activity?

Select one:

a. Ligase

b. Helicase

c. Topoisomerase

d. DNA polymerase

e. Peptidyl transferase

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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

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Transcription is initiated when RNA polymerase binds to

Select one:

a. a promoter

b. an initiator

c. a transciptor

d. a codon

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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

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Which of the following regions of RNAs are translated?

Select one:

a. 5' UTR

b. exons

c. introns

d. 3' UTR

e. poly-A

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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

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Cellular organelles containing hydrolytic enzymes are called:

Select one:

a. peroxisomes

b. lysosomes

c. ribosomes

d. mesosomes

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______ 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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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Biology 1002B Chapter 14.2: Cycle 8 - Regulation of Transcription in Eukaryotes

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