Chapter 12 practice problems/review

Rank the following termination events in sequential order. Place the first event at the top of the list. Release factor binds to stop codon Ribosomal subunits dissociate Protein product is released

1. Release factor binds to stop codon 2. Protein product is released 3. Ribosomal subunits dissociate

List the steps of translation in the correct order

1. initiation 2. elongation 3. termination

Place these steps in DNA replication in the correct sequence beginning with the first step at the top: complimentary base pairing joining nucleotides to the growing DNA strand unwinding the DNA double helix

1. unwinding the DNA double helix 2. complimentary base pairing 3. complimentary base pairing

DNA nucleotides come in ________ different varieties.

4

DNA structure: which one? A always pairs with G and C always pairs with T A always pairs with T and C always pairs with G

A always pairs with T and C always pairs with G

According to the Watson and Crick model, DNA has all of the following characteristics: A is bonded to T antiparallel G is bonded to C runs in a 3' to 5' direction DNA is a single helix

A is bonded to T antiparallel G is bonded to C

What would the mRNA transcript's sequence be if a section of the DNA strand contained the sequence TATGCCCG?

AUACGGGC

Place the following steps in the order in which they occur during gene expression. A B C OR D? A. mRNA is carried to ribosomes in the cytoplasm, mRNA is translated into polypeptides by tRNA, DNA is transcribed into mRNA in the nucleus B. DNA is transcribed into mRNA in the nucleus, mRNA is carried to ribosomes in the cytoplasm, mRNA is translated into polypeptides by tRNA C. DNA is transcribed into mRNA in the nucleus, mRNA is translated into polypeptides by tRNA, mRNA is carried to ribosomes in the cytoplasm D. mRNA is carried to ribosomes in the cytoplasm, DNA is transcribed into mRNA in the nucleus, mRNA is translated into polypeptides by tRNA

B. DNA is transcribed into mRNA in the nucleus, mRNA is carried to ribosomes in the cytoplasm, mRNA is translated into polypeptides by tRNA

What is the best explanation as to why the number of adenines in an organism's DNA is equal to its number of thymines? Because adenine pairs with guanine, and cytosine with thymine Because DNA is only made of adenine or thymine, and they are complementary bases Because adenine pairs with thymine in DNA

Because adenine pairs with thymine in DNA

Why would the number of guanines in an organism's DNA be equal to its number of cytosines? Because DNA is only made of cytosine or guanine, and they are complementary bases Because cytosine pairs with guanine in DNA Because adenine pairs with guanine, and cytosine with thymine

Because cytosine pairs with guanine in DNA

For a protein, gene expression requires ____________ in the nucleus and ____________ at the ribosome to take place.

Blank 1: transcription Blank 2: translation

Select the choices indicating similarities between RNA and DNA. Both contain the base uracil. Both are nucleic acids. Both contain 4 types of nucleotide bases. Both contain the sugar ribose. Both are polymers of nucleotides. Both are double-stranded double-helices.

Both are nucleic acids. Both contain 4 types of nucleotide bases. Both are polymers of nucleotides.

Which of the following are steps in DNA replication? Complementary base pairing Unwinding the DNA double helix Translating mRNA into protein Transcribing DNA into a complementary RNA strand Joining nucleotides to the growing DNA strand

Complementary base pairing Unwinding the DNA double helix Joining nucleotides to the growing DNA strand

Which of the following are steps in DNA replication? Complementary base pairing Transcribing DNA into a complementary RNA strand Translating mRNA into protein Unwinding the DNA double helix Joining nucleotides to the growing DNA strand

Complementary base pairing Unwinding the DNA double helix Joining nucleotides to the growing DNA strand

DNA or RNA: Helix form

DNA

DNA or RNA: bases are adenine, guanine, thymine, and cytosine

DNA

DNA or RNA: contains deoxyribose sugar

DNA

DNA or RNA: double stranded

DNA

DNA structure: which one? DNA is a single stranded molecule DNA is a double helix

DNA is a double helix

DNA structure: which one? DNA is antiparallel meaning the strands are oriented in opposite directions DNA antiparallel meaning the strands are oriented in the same direction as eachother

DNA is antiparallel meaning the strands are oriented in opposite directions

structure of DNA: DNA is referred to as a ___________ meaning that it has _________ strands that are __________ together. The _____________ of DNA form the rungs, linking the ______ strands together through ____________ The backbone of DNA is comprised of ____________ sugar and a ______________. The strands are ____________, meaning they are __________ but are oriented in __________ directions. Adenine is always paired with _________ and cytosine is always paired with __________.

DNA is referred to as a double helix, meaning that it has 2 strands that are twisted together. The nitrogen bases of DNA form the rungs, linking the 2 strands together through hydrogen bonds. The backbone of DNA is comprised of deoxyribose sugar and a phosphate group. The strands are antiparallel, meaning they are parallel but are oriented in opposite directions. Adenine is always paired with thymine and cytosine is always paired with guanine.

Which of the following is the correct enzyme that is used for proofreading the replication of DNA?

DNA polymerase

the synthesis of new DNA double helix molecules from a pre-existing parent molecule is called _______.

DNA replication

semiconservative replication: DNA replication is achieved by a process called _______________ replication, meaning that each new double helix includes an _________ strand from the parent DNA and a ___________ strand. After the DNA double helix unwinds, each old strand serves as a ___________ for the formation of a new strand. Complementary ____________ base pair with those of the old strand. After replication is complete, there are ___________ daughter DNA double helices. Each daughter double helix has the ________ sequence of base pairs that the __________ double helix had before replication began.

DNA replication is achieved by a process called semiconservative replication, meaning that each new double helix includes an old strand from the parent DNA and a new strand. After the DNA double helix unwinds, each old strand serves as a template for the formation of a new strand. Complementary nucleotides base pair with those of the old strand. After replication is complete, there are two daughter DNA double helices. Each daughter double helix has the same sequence of base pairs that the parental double helix had before replication began.

Which choice identifies the flow of information according to the central dogma of molecular biology? Protein to RNA to DNA Protein to DNA to RNA DNA to protein to RNA DNA to RNA to protein

DNA to RNA to protein

DNA replication: During DNA replication, the double-stranded DNA ___________ as the ____________ bonds connecting the parent strands are ____________. An enzyme called ____________ is responsible for this step. New _____________ position themselves along the parent strands through _____________________. The nucleotides are ____________ to each other by an enzyme called _______________ Now, __________ new daughter DNA molecules are produced, each consisting of one old _____________ and one new _____________, rendering DNA replication a _____________ process.

During DNA replication, the double-stranded DNA unwinds as the hydrogen bonds connecting the parent strands are broken. An enzyme called helicase is responsible for this step. New nucleotides position themselves along the parent strands through complementary base pairing. The nucleotides are joined to each other by an enzyme called DNA polymerase. Now, two new daughter DNA molecules are produced, each consisting of one old parent strand and one new daughter strand, rendering DNA replication a semiconservative process.

Which of the following facilitates the binding of tRNA anticodons to mRNA codons? Stop codon Initiator tRNA Elongation factors Release factors

Elongation factors

Which of the following contain proper complementary DNA base pairs? Multiple select question. G - T A - U G - C C - C A - T A - G A - A A - C C - T

G - C A - T

the genetic code: Information within ____________ is contained within the sequence of the _______________ When DNA is ___________ into mRNA, sets of three nucleotides, also called __________, code for specific ____________. There are ______ different ___________ that can combine to form the countless proteins needed by living organisms. Almost all organisms use this ____________, suggesting an __________ evolutionary origin.

Information within DNA and RNA is contained within the sequence of the nitrogenous bases. When DNA is transcribed into mRNA, sets of three nucleotides, also called codons, code for specific amino acids. There are 20 different amino acids that can combine to form the countless proteins needed by living organisms. Almost all organisms use this genetic code, suggesting an early evolutionary origin.

What type of RNA is needed to begin translation?

Initiator tRNA

A portion of an mRNA transcript has the sequence CUGAAA. Assuming no modification occurs, what would be the sequence of amino acids in the protein product? (Use the mRNA codon table.)

Leucine - lysine

Which of the following directly plays a part in translation initiation? Messenger RNA Initiator tRNA Large ribosomal subunit Template DNA strand Small ribosomal subunit

Messenger RNA Initiator tRNA Large ribosomal subunit Small ribosomal subunit

Which of the following are components of a nucleotide? Nitrogen-containing base 5-carbon sugar Lipid and a protein Phosphate

Nitrogen-containing base 5-carbon sugar Phosphate

Select the items that describe events occurring during the termination phase of translation. Protein product is released. Release factor binds to stop codon. tRNA binds to E, P, or A sites. Ribosomal subunits dissociate. mRNA exits the nucleus of eukaryotes.

Protein product is released. Release factor binds to stop codon. Ribosomal subunits dissociate.

DNA or RNA: bases are adenine, guanine, uracil and cytosine

RNA

DNA or RNA: contains ribose sugar

RNA

DNA or RNA: single stranded

RNA

DNA or RNA: sometimes exhibits secondary structure such as hairpins

RNA

What is the name of the enzyme complex responsible for synthesizing a new RNA molecule through nucleotide binding?

RNA polymerase

DNA structure: which one? The backbone is made up of deoxyribose sugar and phosphate groups the backbone is made of ribose sugar and nitrogen bases

The backbone is made up of deoxyribose sugar and phosphate groups

why replication errors in DNA are infrequent: The enzyme that positions complementary nucleotides on growing daughter strands during DNA replication is called _________________. If an error occurs during the replication process, that error would be passed on to all subsequent ____________ strands, resulting in ___________ in the organism. Over time, this could cause a sequence of DNA to contain numerous ___________, which could result in __________ or other physical anomalies. For this reason, ____________ also ___________ the growing strand and removes any ___________ nucleotides. This process is extremely __________, allowing as few as one mistake in over 1 billion!

The enzyme that positions complementary nucleotides on growing daughter strands during DNA replication is called DNA polymerase. If an error occurs during the replication process, that error would be passed on to all subsequent daughter strands, resulting in mutations in the organism. Over time, this could cause a sequence of DNA to contain numerous mutations, which could result in cancer or other physical anomalies. For this reason, DNA polymerase also proofreads the growing strand and removes any mismatched nucleotides. This process is extremely efficient, allowing as few as one mistake in over 1 billion!

What is the source of particular sequences of tRNA, mRNA, and rRNA?

Transcription from DNA

Semiconversative replication

Type of DNA replication in which the replicated double helix consists of one old strand, derived from the parental model, and one newly made strand.

If a certain section of a template strand of DNA had the sequence AATGCCCG, the mRNA transcript's sequence would be

UUACGGGC

RNA polymerase has all the following in common with DNA polymerase: a growing strand runs in a 5' to 3' direction nucleotides are added to the 3' end a double helix is the final product nucleotides are joined together

a growing strand runs in a 5' to 3' direction nucleotides are added to the 3' end nucleotides are joined together

During the process of translation, a codon matches up with its complement, a(n) __________

anticodon

The term that refers to the strands of a DNA molecule being oriented in opposite directions is ___________

antiparallel

When two molecular strands are connected but oriented in opposite directions, the strands are said to be ______.

antiparallel

DNA structure: which one? Bases are attached to backbone and face outwards away from eachother bases are attached to the backbone and face inwards towards eachother

bases are attached to the backbone and face inwards towards eachother

rRNA, mRNA or tRNA? closely associated with DNA in the nucleus? contains anticodons? produced in the nucleus and assembled in the cytoplasm?

closely associated with DNA in the nucleus: mRNA contains anticodons: tRNA produced in the nucleus and assembled in the cytoplasm: rRNA

An anticodon is the compliment of the ______.

codon

mRNA contains three base units of RNA that are called _____, each of which code for one amino acid

codons; mRNA is divided into three-base units called codons.

DNA structure: which one? each nucleotide contains a phosphate group at the 5' end of the sugar each nucleotide contains a phosphate group at the 3' end of the sugar

each nucleotide contains a phosphate group at the 5' end of the sugar

The polypeptide increases in size one amino acid at a time during the phase of translation called

elongation

Translation allows additional amino acids to be added to the growing polypeptide during the _____ phase.

elongation

The production and usage of a gene's product is called gene ________

expression

What is the function of the promoter? guides RNA polymerase to the strand to be transcribed defines the direction of transcription defines the start of transcription defines the start of translation

guides RNA polymerase to the strand to be transcribed defines the direction of transcription defines the start of transcription

Complimentary bases are held together in the DNA strand by ___________ bonds.

hydrogen

The two strands of a DNA double helix are held together by

hydrogen bonds.

Select the characteristics of translation. involves a mRNA molecule occurs in eukaryotic nuclei results in a protein product involves RNA polymerase

involves a mRNA molecule results in a protein product

rRNA, mRNA or tRNA? Messenger RNA?

mRNA

rRNA, mRNA or tRNA? produced in the nucleus and assembled in the cytoplasm?

mRNA

DNA is composed of units called ____________, each of which contains a phosphate group, a 5-carbon sugar, and one of 4 nitrogen-containing bases.

nucleotides

The building blocks of DNA are ________

nucleotides

In eukaryotes, transcription occurs in the ____________, and translation occurs in the ___________.

nucleus, cytoplasm

DNA, or the instructions for making proteins, is found within the _____ of the cell; while protein synthesis machinery is found in the _____ of the cell.

nucleus; cytoplasm

Which of the following are true of transcription but not translation? involves tRNA molecules and amino acids occurs in eukaryotic nuclei produces RNA results in a protein product

occurs in eukaryotic nuclei produces RNA

Select the choices indicating differences between RNA and DNA. only DNA is considered a nucleic acid only RNA contains the base "Uracil" DNA has 4 types of nucleotide bases, but RNA only has 3 only DNA is considered a polymer of nucleotides DNA is double-stranded, but RNA is single-stranded only RNA contains the sugar "ribose"

only RNA contains the base "Uracil" DNA is double-stranded, but RNA is single-stranded only RNA contains the sugar "ribose

The enzyme that is used to proofread DNA as it is being synthesized is DNA _________

polymerase

During the termination stage of translation a completed ______ is released.

polypeptide

Which of the following are true of transcription but not translation? produces RNA involves tRNA molecules and amino acids occurs in eukaryotic nuclei results in a protein product

produces RNA occurs in eukaryotic nuclei

To initiate transcription, RNA polymerase binds to the __________ region of the gene.

promoter

rRNA, mRNA or tRNA? Ribosomal RNA?

rRNA

The process of copying a DNA molecule so that there are two copies of the same DNA is called DNA ________

replication

DNA replication produces a resulting daughter DNA that consists of one parent strand and one daughter strand. DNA replication is referred to as _____________ replication.

semiconservative

Which of the following is/are true of both transcription and translation? several, identical products can be produced from one strand RNA is involved occur in eukaryotes and prokaryotes involve nucleic acids occur in the nucleus of eukaryotes involve DNA Polymerase

several, identical products can be produced from one strand RNA is involved occur in eukaryotes and prokaryotes involve nucleic acids

During transcription, double-stranded DNA is transcribed into a complementary molecule of

single-stranded mRNA; Single-stranded mRNA is synthesized during transcription.

The codon near which the small ribosomal subunit attaches to the mRNA molecule to be translated, which codes for methionine (AUG) is called the ___________codon.

start

During translation initiation, the small ribosomal subunit and initiator tRNA attach in the vicinity of the _____.

start codon

Which nucleic acid is the physical carrier of individual amino acids?

tRNA

Which version of RNA transfers amino acids to the ribosome?

tRNA

rRNA, mRNA or tRNA? contains anticodons?

tRNA

rRNA, mRNA or tRNA? transfer RNA?

tRNA

Which of the following play a part in translational elongation? tRNA Elongation factors Release factors mRNA Stop codon

tRNA Elongation factors mRNA

Which of the following play a part in translational elongation? Release factors tRNA mRNA Stop codon Elongation factors

tRNA mRNA Elongation factors

During the process of translation, mRNA is carried to the ribosome, where it is translated into polypeptides by _____ molecules.

tRNA; During translation, mRNA is translated into polypeptides by tRNA molecules.

The original parent strand from which a complementary strand is made is called the ___________ strand.

template

The parental strand of DNA serving as the guide for a complementary DNA daughter strand is called the ______ strand.

template

A completed polypeptide is released during the phase of translation called _________

termination

In the term tRNA, the t stands for

to transfer

The process of synthesizing an RNA strand from a DNA template strand is called

transcription

Based on your understanding of the central dogma of molecular biology, match the following processes with the correct description. Options: transcription translation replication match: DNA is used as a template to produce RNA RNA is used to produce proteins DNA is used as a template to produce duplicate molecules of DNA

transcription: DNA is used as a template to produce RNA. translation: RNA is used to produce protein. replication: DNA is used as a template to produce duplicate molecules of DNA.

rRNA, mRNA or tRNA? transfer RNA? Ribosomal RNA? Messenger RNA?

transfer RNA: tRNA Ribosomal RNA: rRNA Messenger RNA: mRNA

Polypeptides are created during which process?

translation

The process which occurs on ribosomes, either free in the cytoplasm or bound to the endoplasmic reticulum is called

translation

The process which uses mRNA, tRNA, and ribosomes to synthesize proteins is called

translation

True or false: A purine base normally pairs with a pyrimidine base.

true

True or false: The DNA double helix is made up of one older strand and one newer strand.

true