Chapter 5

DNA Polymerase

During DNA replication, which enzyme is involved in proofreading to prevent the incorrect matching of nucleotides?

conjugation, F+

During _________ a pilus forms between an F+ and an F-cell and allows for the exchange of genetic material. By the end of the process, the previously F-cell is converted to a(n) _________ cell.

translation amino acids

During _________, tRNAs serve as adapter molecules to bring _________ to the ribosome to build a protein.

constitutive genes

During optimum conditions, E. coli will replicate every 20 minutes. Because the genes required for replication are needed as part of a routine function, these genes are considered __________.

rna polymerase

Enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription

restriction enzymes

Enzyme that cuts DNA at a specific sequence of nucleotides

CH3

Genes can be silenced by a process called DNA methylation. Which of the following compounds is a methyl group?

transformation

Griffith's experiment proved that bacteria can take up naked DNA from the environment and use it as part of their genome. This process, which can occur in a laboratory or in a natural setting, is called __________.

Methyl groups

Groups added to the daughter strand for DNA polymerase to use during proofreading.

Ribonucleotides contain ribose instead of deoxyribose, which is found in deoxyribonucleotides. Ribonucleotides are used to build RNA, while deoxyribonucleo-tides are used to build DNA. Ribonucleotides will not incorporate thymine as a nitrogen base and instead use uracil; 1

How is a ribonucleotide different from a deoxyribonucleotide?

competent

If a cell is to be transformed in a lab, the cell must be __________ to uptake the available genetic information.

DNA polymerase I

Important for removing RNA primers on the lagging strand

the lagging strand, because the DNA polymerase can move only in the 5' to 3' direction

In DNA replication, Okazaki fragments are required in synthesizing __________.

eukaryotic cells

In DNA replication, protein factors are more heavily required for replication in __________. (eukaryotic or prokaryotic cells)

DNA polymerase III

In DNA replication, what is the main enzyme responsible for adding complementary nucleotides to the daughter strand while reading the parent strand?

Repressor Protein

In an inducible operon, what protein is used to turn off transcription by binding to the operator sequence?

introns

In eukaryotic mRNA, there are sequences of mRNA that do NOT encode for specific amino acids and do NOT contribute to the protein. These sequences are called __________.

lactose, glucose

In order for the lactose operon to be "on" and actively transcribed, _________ must be present and _________ must be absent.

It can undergo vertical gene transfer.

Of the following statements, which does NOT apply to a microorganism that has a fertility plasmid? -It has a pilus. -It can undergo vertical gene transfer. -It can further develop into a Hfr cell. -It can undergo horizontal gene transfer.

They create a stable, non-changing genome.

Of the following statements, which one is NOT related to transposable elements? - They create a stable, non-changing genome. - They can change the rate of gene expression. - They recombine the genome. - They require the transposase enzyme.

stop codon (or nonsense codon)

Once the ribosome reaches a _________ on the mRNA, translation ends.

prokaryotic translation is polycistronic, and eukaryotic translation is almost always monocistronic.

One major difference between prokaryotic and eukaryotic translation is __________.

RNA

Primase lays down a short piece of __________ as a primer to start DNA replication.

primosome

Protein complex responsible for creating RNA primers on single stranded DNA during DNA replication

would die

Proteins provide cells with the necessary equipment to perform normal cellular activity. Without gene expression the cell __________.

autoinducers

Quorum sensing allows bacteria within communities to communicate with chemical messages, which may help regulate gene expression. The chemical messages are called __________.

Ribose

RNA nucleotides are made of a sugar, a phosphate, and a nitrogen base. Which sugar is unique to RNA nucleotides and NOT found in DNA nucleotides?

DNA Polymerase I

RNA primers are removed from the leading and lagging strand by __________.

Histidine

The Ames test is used to identify if a chemical will result in mutations. This test uses the microorganism S. typhimurium and the amino acid __________. proline glycine histidine lysine

conjugation

The exchange of genetic information by use of a pilus and cell-to-cell interaction is called __________.

genotype

The genetic makeup of an organism is its __________.

DNA polymerase III

The primary enzyme that copies DNA

excision repair

The process of removing incorrect nucleotides and replacing them with correct ones is referred to as __________. excision repair base substitution mutation correction replication repair

horizontal gene transfer

The process of transferring of genetic information between cells in the same generation is referred to as __________.

RNA polymerase to the promoter region of the intended gene to be transcribed

The role of transcription factors is to signal __________.

different codons that code for the same amino acid

The term "redundancy" in molecular biology refers to __________.

Central Dogma of Biology

The term used by molecular biologists to describe the flow of genetic information from DNA, to RNA, to protein is the __________.

selenocysteine and pyrrolysine

There are two nonstandard encoding amino acids: __________.

Primosome

To start DNA replication, the origin of replication is recognized by a collection of factors called the __________.

specialized transduction

Transduction that involves a temperate phage integrating into the host cell genome is called __________.

thymine dimers

UV radiation can result in __________ in a cell's DNA. nonsense mutation silent mutation frameshift mutation thymine dimers

DNA ploymerase

What is the main enzyme required for transcription of a gene?

nucleoid

Where is the chromosomal DNA found in prokaryotic cells?

DNA polymerase III

Which enzyme is the main contributor to the development of spontaneous mutations? DNA polymerase III helicase ligase RNA primase.

phosphate group

Which functional group is found at the 5' end of DNA?

a repressed operon

Which of the following is considered a pre-transcriptional regulation and NOT a post-transcriptional regulation? - the rate of mRNA processing in eukaryotic cells - a repressed operon - the rate of ribosome association with the mRNA - messenger RNA stability

Frameshift

Which of the following mutations is the most detrimental to the cell? frameshift mutation missense mutation nonsense mutation silent mutation

Uracil

Which of the following nucleotides is found only in RNA and not in DNA? cytosine, guanine, adenine, uracil

Plasmids are part of the cell's chromosome.

Which of the following statements is NOT a characteristic of plasmids? -Plasmids are part of the cell's chromosome. -Plasmids are involved in horizontal gene transfer. -Plasmids replicate independently of the cell's chromosome. -Plasmids carry genes that may be involved in antibiotic resistance.

They are found only in prokaryotic cells. (they are found in both)

Which of the following would be considered a FALSE statement about small noncoding RNAs? - They are used in post-transcription regulation. - They reduce the amount of protein made from mRNA. - They are found only in prokaryotic cells. - They can be used to tag a ribosome to be destroyed.

tRNA

Which type of RNA carries in amino acids and adds the amino acids to the "A" site in the ribosome?

Plasmids

Which type of genetic material may be found in both prokaryotic and eukaryotic cells and may contain genes conferring antibiotic resistance?

Physical

biological, chemical, or physical mutagen? X-Rays

chemical

biological, chemical, or physical mutagen? Alcohol

Chemical

biological, chemical, or physical mutagen? Cigarette Smoke

biological

biological, chemical, or physical mutagen? Plasmids

Biological

biological, chemical, or physical mutagen? Transposons

Physical

biological, chemical, or physical mutagen? UV Radiation

Biological

biological, chemical, or physical mutagen? Viruses

reverse transcriptase

cDNA is a product of the action of __________.

epigenetic regulation

changes in gene expression that are due to environmental effects rather than to changes in the nucleotide sequence of the gene

Translation

decoding of a mRNA message into a polypeptide chain

Central Dogma of Molecular Biology

information is transferred from DNA to RNA to protein

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

frameshift mutation

mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide

rRNA

ribosomal RNA; type of RNA that makes up part of the ribosome

transcription

synthesis of an RNA molecule from a DNA template

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

helicase

unwinds DNA helix

Redundancy, triplet code, 64 different codons that encode 20 different amino acids, 2 stop signals, and one start signal

3 Features of the genetic code

three

A codon consists of __________ nucleotides.

Single-strand DNA binding protein

Keep DNA strands separated during replication

Primase

Lays RNA primers to start DNA replication

gene library

Mixed collection of bacteria that house many different cloned DNA fragments

Gyrase

Relieves the coiling tension in DNA as it is unwound,

parts of mRNA that are not translated and act as post-transcription regulators

Riboswitches are best defined as __________. parts of mRNA that are not translated and act as pre-transcription regulators parts of mRNA that are not translated and act as post-transcription regulators parts of mRNA that block the first tRNA from entering into the "A" site of the ribosome factors that block the ribosome from binding

e. RNA primase builds RNA in transcription

Select the false statement: a. DNA is made of deoxyribonucleotides. b. RNA is made of ribonucleotides. c. RNA is built in a 5' to 3' direction. d. DNA is built in a 5' to 3' direction. e. RNA primase builds RNA in transcription.

RNA primer

Serves as a jump-start platform for DNA polymerase I;

Okazaki fragments

Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.

False. (DNA has an antiparallel arrangement)

T or F DNA has a parallel arrangement

True

T or F DNA ligase forms phosphodiester bonds between Okazaki fragments on the lagging strand.

True

T or F In DNA, C bonds with G.

True

T or F In RNA, A bonds to U.

False. (Eukaryotic mRNA requires processing before it is translated)

T or F Prokaryotic mRNA requires processing before it is translated

False (DNA contains deoxyribonucleotides; RNA con-tains ribonucleotides)

T or F RNA contains deoxyribonucleotides

True

T or F RNA primase is required on the leading and the lagging strand.

False. (DNA is replicated in a 5′ to 3′ direction)

T or F DNA is replicated in a 3' to 5' direction.

DNA Replication

the process of making a copy of DNA

PCR (polymerase chain reaction)

A method used to rapidly make multiple copies of a specific segment of DNA; can be used to make millions of copies of DNA from a very small amount of DNA

Repressor

A protein that binds to an operator and physically blocks RNA polymerase from binding to a promoter site

plasmid

A small, circular section of extra DNA that confers one or more traits to a bacterium and can be reproduced separately from the main bacterial genetic code.

Inducer

A specific small molecule that binds to a bacterial repressor protein and changes the repressor's shape so that it cannot bind to an operator, thus switching an operon on.

retrotransposon

A transposon that relies on an RNA intermediate is called a __________.

addition of a methionine

After translation, protein modifications are necessary for a final functioning product. Which of the following is NOT part of protein modification?

tRNA (anticodon)

An anticodon is found on __________.

5'-TGCATAGGTCGTCGAGGTGGTT-3'

Assume you have the DNA sequence 3'-ACGTATCCAGCAGCTCCAC-CAA-5'. Use the genetic code table found in the chapter to answer the fol-lowing questions: a. What would the complementary DNA sequence be?

5'-UGCAUAGGUCGUCGAGGUGGUU-3'

Assume you have the DNA sequence 3'-ACGTATCCAGCAGCTCCAC-CAA-5'. Use the genetic code table found in the chapter to answer the following questions: What would the corresponding mRNA sequence be?

three mRNA

Codons are _________ nucleotides long and are in _________, which is transcribed from DNA.

quorum sensing

Communicate and cooperate in the formation and function of biofilms

No. No start codon

Could the mRNA sequence you generated (5'-UGCAUAGGUCGUCGAGGUGGUU-3') be translated? Why or why not?