BISC104: Gene Expression

select all of the following that are true about nucleic acids?

-Most amino acids are specified by more than one codon. -Some codons do not specify an amino acid but rather signal translation to stop

How many subunits make up a ribosome?

2 (large and small)

When making an mRNA transcript, RNA polymerase moves from

5' to 3' adding RNA nucleotides to the 3' end.

Transfer RNA (tRNA) carrying an amino acid binds to a ribosome at the ______.

A site

are three-nucleotide sequences that occur on mRNA and code for a specific amino acid to be added to the polypeptide chain.

Codons

The promoter is a region of the ______ where RNA polymerase binds to initiate transcription.

DNA

Which of the following best describes mRNA?

a copy of a gene used to produce a protein

In translation, a sequence of nucleotides is translated into a sequence of ______.

amino acids

One end of tRNA binds an amino acid, while the other contains an anticodon that binds to ______.

an exposed complementary codon on the mRNA

Given a codon on mRNA of AUG, the _______ on the tRNA molecule would be UAC.

anticodon

In prokaryotic DNA, a site called the operator ______.

binds the repressor

To begin transcription, RNA polymerase

binds to one strand of the DNA double helix that contains a promoter-site sequence it recognizes.

Sections of a eukaryotic gene that do not encode polypeptides and that are removed during RNA processing are called ______.

introns

In RNA processing, ______ are removed from the primary RNA transcript to form the ______.

introns; mature mRNA

According to the central dogma, the genes contained in ______ are copied into RNA, which is used to direct the assembly of a sequence of amino acids in a ______.

DNA; Protein

When making mRNA using DNA, ______.

RNA polymerase pairs up an RNA nucleotide with a DNA nucleotide

Controlling whether ______ is able to bind to the ______ will affect the initiation of gene transcription in prokaryotes.

RNA polymerase; promoter

Why is the process of creating a protein from mRNA called translation?

The chemical language changes from the nucleotides of RNA to amino acids in the protein.

Select all of the following that are true about transfer RNA (tRNA).

contains an anticodon on one of its loops has a folded, three-loop structure has an amino acid attachment site at its 3' end

Select all of the following that are true about an anticodon.

determines which amino acid will attach to a tRNA molecule complementary to a codon

_____ are the sections of DNA that encode the amino acid sequence of a polypeptide, whereas ______ are noncoding sections of DNA that must be removed during processing of the mRNA transcript.

exons; introns

A _____ is a short segment of DNA that encodes for a specific protein.

gene

The information specifying hereditary traits is encoded in blocks of DNA called

genes

In gene expression, ______.

information in DNA directs the synthesis of a specific polypeptide

The subunits of a ribosome ______.

nest together to form a functional unit

The regulation of gene expression ensures that

not all genes are expressed at all times.

Control of gene expression in prokaryotes is designed to produce ______.

only the proteins needed based on environmental conditions

In prokaryotic cells, the region of the DNA where the repressor binds is the ______.

operator

A repressor stops transcription in prokaryotic cells by ______.

preventing the binding of RNA polymerase to the promoter

Following the RNA transcript contains the entire gene, both introns and exons.

primary

In a ______ cell, a gene can be translated as it is being transcribed.

prokaryotic

Starting at the ______ located at the beginning of a gene, RNA polymerase synthesizes ______.

promoter; an mRNA transcript of the DNA

The type of RNA that is a component of ribosomes is

rRNA.

A region of ______ found in the small subunit of the ribosome corresponds to the leader region of all genes and causes the ______ to bind correctly to the ribosome during initiation of translation.

rRNA; mRNA

The attachment of a special signal molecule to the repressor can ______.

remove the repressor from the DNA

exons are ___

sections of eukaryotic genes that encode polypeptides

Transcription refers to the process of

synthesizing RNA from a DNA template.

The three sites on the ribosome that form dents or pockets are the sites where _____ binds.

tRNA

What type of RNA brings amino acids to the ribosome during translation?

tRNA

Select all of the following that are steps leading to the production of a protein in eukaryotes.

tRNA carries amino acids to the ribosome. The primary mRNA transcript is processed to form mRNA. DNA is transcribed into mRNA.

In this diagram of a(n) ______ molecule, letter A represents the ______, and letter B represents the ______.

tRNA; amino acid attachment site; anticodon

During transcription, RNA polymerase binds to one strand of DNA, which is called the ______ strand, and adds complementary nucleotides to the DNA, using ______ instead of thymine.

template; uracil

Translation is the term used to describe ______.

the production of a protein using mRNA

What process results in the production of messenger RNA?

transcription

The mRNA product of ______ is used by ribosomes to produce a polypeptide in ______.

transcription; translation

During ____ the mRNA transcript is used to direct synthesis of a protein.

translation

CAP/cAMP

What complex acts as an activator at the lac operon?

Ribosomes are composed of proteins and ____ RNA (rRNA).

ribosomal

What did biologists use to help them determine which amino acid matched to a codon?

trial and error artificial mRNA

match each site with its description

A site--- Site where incoming tRNAs with bound amino acids enter the ribosome. Site where incoming tRNAs with bound amino acids enter the ribosome. P site---The site where peptide bonds form between the incoming amino acid and the growing peptide chain. The site where peptide bonds form between the incoming amino acid and the growing peptide chain. E site---The site where tRNAs are released from the mRNA. The site where tRNAs are released from the mRNA.

The codon ______ is the start codon on the mRNA and will bind to a tRNA anticodon with the sequence ______.

AUG; UAC

The use of information contained in DNA to direct the production of specific proteins is known as ______.

Gene expression

Select the correct statement about genes in prokaryotic and eukaryotic cells.

In prokaryotic cells, genes occur as unbroken sections of DNA, while in eukaryotic cells, genes have interrupting segments called introns.

In eukaryotes, why do primary RNA transcripts have to be processed to form mature mRNA transcripts?

Introns have to be removed before translation.

Select all of the following that are true about translation.

It is the second stage of gene expression. Information is transferred from RNA to protein

For the DNA sequence AAGTTC RNA polymerase would transcribe the sequence ______ in the mRNA molecule.

UUCAAG

Given the mRNA nucleotide sequence AUGACAAGUGGCCGA, choose the amino acid sequence it would produce.

Methionine - Threonine - Serine - Glycine - Arginine

The unprocessed mRNA transcript is called a ______ transcript.

Primary RNA

Given the mRNA nucleotide sequence CCCAACAGCGAGGCC, choose the amino acid sequence it would produce.

Proline - Asparagine - Serine - Glutamate - Alanine

The site on the DNA where RNA polymerase binds at the start of transcription is called the ______.

Promoter

Select the correct statements about the process of translation.

The sequence of the mRNA determines what tRNAs will bind, and what amino acids will be added to the polypeptide. The ribosome moves down the mRNA three nucleotides at a time. At translation initiation, mRNA binds to the small subunit of a ribosome, and then the large subunit binds to form a complete ribosome. The tRNA bound at the P site moves to the E site as the ribosome moves to the next codon.

Why can transcription and translation take place at the same time in prokaryotes?

There is no nuclear membrane to act as a barrier.

At what stage do prokaryotes control most of gene expression?

Transcription

During _____ an mRNA copy of a gene is made. The mRNA is able to leave the nucleus, where the DNA is stored, and travel to the cytoplasm for protein synthesis

Transcription

RNA polymerase synthesizes mRNA during ______.

Transcription

During translation _____ RNA (tRNA) is responsible for bringing the amino acids to the ribosome to be added to the polypeptide chain.

Transfer

During ______ the mRNA transcript is used to direct synthesis of a protein.

Translation

In gene expression, the production of a protein from RNA is called ______.

Translation

In translation, a codon is ______.

a group of three nucleotides that determine the amino acid to be added to a polypeptide

An activator in prokaryotic cell transcription is

a regulatory protein that binds to the DNA and makes the promoter more accessible to RNA polymerase.

Over 50 different proteins and rRNA make up ______.

a ribosome

In a prokaryotic cell, an operon is ______.

a section of DNA containing a cluster of genes that are transcribed together

Select modifications made to the primary RNA transcript in eukaryotes that protect the RNA from degradation.

addition of a poly-A tail addition of a 5' cap

Alternative splicing of the exons of an RNA transcript ______.

allows the production of different proteins from the same gene

The removal of introns in the primary mRNA transcript and the joining of the remaining exons in different ways is called ______.

alternative splicing

RNA polymerase transcribes DNA into mRNA using ______.

complementary base pairing rules

Select all of the following that describe genes in eukaryotes.

contain sections called exons that encode polypeptides have interrupting segments called introns

During translation the ______ is used to direct the synthesis of the protein by providing the directions taken from the DNA.

mRNA

Transcription is the process of creating a(n) ______ copy of a(n) ______.

mRNA; gene

What type of RNA conveys the information contained in a DNA sequence to the cytoplasm and directs the sequence of amino acids in a polypeptide?

messenger RNA

In the genetic code, each sequence of ______ nucleotides corresponds to a(n) _______.

three; amino acid

Artificial mRNA consisting of repeated nucleotides, such as UUUUUUUUUUUUU, were used ______.

to determine which codons correspond to which amino acids

In eukaryotes, why are the 5' cap and poly-A tail added to the primary RNA transcript?

to protect the RNA transcript from degradation

In a process called _______, an mRNA copy is made of DNA.

transcription