Question 1

Eukaryotic mRNAs have a 7-methylguanosine cap on their 3ʹ end.

Accepted Answer

A) True 
 B)False

Question 2

Some chaperones were originally known as heat-shock proteins because they are expressed in cells subjected to high temperatures and facilitate the refolding of denatured proteins.

Accepted Answer

A) True 
 B)False

Question 3

What would happen in a bacterium in which the Shine-Dalgarno sequence was mutated?

Accepted Answer

The Shine-Dalgarno sequence is required

Question 4

What function does covalent modification of proteins serve in the cell that proteolysis cannot?

Accepted Answer

Both mechanisms regulate enzym

Question 5

Glycosylphosphatidylinositol (or GPI) anchors are found

Accepted Answer

A)  at the carboxy terminus of membrane proteins. 
B)  at the amino terminus of membrane proteins. 
C)  on the cytoplasmic side of membrane channel proteins. 
D)  on the amino terminus of the 28S of certain ribosomal complexes associated with secretion. 
A)  at the carboxy terminus of membrane proteins. 
B)  at the amino terminus of membrane proteins. 
C)  on the cytoplasmic side of membrane channel proteins. 
D)  on the amino terminus of the 28S of certain ribosomal complexes associated with secretion.

Question 6

The growing polypeptide chain coming off the ribosomal complex is fairly unstable. It has a tendency to fold back on itself and can aggregate with adjacent polypeptides. If these processes are allowed to occur, degraded, improperly folded, or large aggregates of nonfunctional proteins would result. How does the cell prevent this?

Accepted Answer

A class of proteins called chaperones pr

Question 7

What is allosteric regulation of a protein?

Accepted Answer

When a protein is regulated allosterical

Question 8

Translation can be regulated by proteins that bind to the 3ʹ untranslated regions of mRNAs.

Accepted Answer

A) True 
 B)False

Question 9

The first step in the initiation of protein synthesis is the binding of _______ to the _______.

Accepted Answer

A)  initiation factors; initiation codon 
B)  initiation factors; small ribosomal subunit 
C)  the small ribosomal subunit; initiation codon 
D)  the initiator tRNA; initiation codon 
A)  initiation factors; initiation codon 
B)  initiation factors; small ribosomal subunit 
C)  the small ribosomal subunit; initiation codon 
D)  the initiator tRNA; initiation codon

Question 10

Many chaperones are called heat-shock proteins because they

Accepted Answer

A)  are expressed at higher levels after a heat shock than under normal growth conditions. 
B)  cause fever in mammals. 
C)  misfold during a heat shock. 
D)  denature at high temperatures. 
A)  are expressed at higher levels after a heat shock than under normal growth conditions. 
B)  cause fever in mammals. 
C)  misfold during a heat shock. 
D)  denature at high temperatures.

Question 11

The enzyme protein disulfide isomerase, which facilitates breakage and reformation of disulfide bonds, is located primarily in the

Accepted Answer

A)  cytosol. 
B)  lumen of the endoplasmic reticulum. 
C)  matrix of mitochondria. 
D)  lumen of lysosomes. 
A)  cytosol. 
B)  lumen of the endoplasmic reticulum. 
C)  matrix of mitochondria. 
D)  lumen of lysosomes.

Question 12

An 80S eukaryotic ribosome is made up of one large 50S subunit and one small 30S subunit.

Accepted Answer

A) True 
 B)False

Question 13

Translation is initiated by the binding of the methionyl tRNA and the mRNA to the _______ subunit, after which the other subunit joins the complex.

Accepted Answer

The answer of Translation is initiated by the binding of...

Question 14

Which statement is true and provides evidence that a certain component of the ribosome catalyzes protein synthesis?

Accepted Answer

A)  Ribosomes are inactive after protease digestion. 
B)  Ribosomes are inactive after RNase digestion. 
C)  Structural analysis shows that proteins occupy the catalytic site where peptide bonds are formed. 
D)  Structural analysis shows that mRNA occupies the catalytic site where peptide bonds are formed. 
A)  Ribosomes are inactive after protease digestion. 
B)  Ribosomes are inactive after RNase digestion. 
C)  Structural analysis shows that proteins occupy the catalytic site where peptide bonds are formed. 
D)  Structural analysis shows that mRNA occupies the catalytic site where peptide bonds are formed.

Question 15

Protein phosphatases

Accepted Answer

A)  catalyze the addition of phosphate residues to proteins. 
B)  catalyze the removal of phosphate residues from proteins. 
C)  catalyze the addition of glycosylphosphatidylinositol to proteins. 
D)  are proteins that specifically bind phosphorylated proteins. 
A)  catalyze the addition of phosphate residues to proteins. 
B)  catalyze the removal of phosphate residues from proteins. 
C)  catalyze the addition of glycosylphosphatidylinositol to proteins. 
D)  are proteins that specifically bind phosphorylated proteins.

Question 16

Experimentally you measure the number of mRNAs being processed from a single gene at 40 copies per minute, yet based on the rate at which ribosomes scan, there should only be about three copies per minute. How might this be explained?

Accepted Answer

This is most likely due to the

Question 17

A proteasome is a

Accepted Answer

A)  vesicle containing proteolytic enzymes. 
B)  precursor to lysosomes. 
C)  complex of a proteolytic enzyme and the protein that is being degraded. 
D)  multisubunit protease complex that degrades proteins marked for destruction. 
A)  vesicle containing proteolytic enzymes. 
B)  precursor to lysosomes. 
C)  complex of a proteolytic enzyme and the protein that is being degraded. 
D)  multisubunit protease complex that degrades proteins marked for destruction.

Question 18

Translation always occurs on which of the following structures?

Accepted Answer

A)  Ribosomes 
B)  Endoplasmic reticulum 
C)  Nuclear envelope 
D)  Mitochondria 
A)  Ribosomes 
B)  Endoplasmic reticulum 
C)  Nuclear envelope 
D)  Mitochondria

Question 19

Which statement regarding tRNAs is false?

Accepted Answer

A)  tRNAs are approximately 70-80 bases long and form a cloverleaf structure. 
B)  All tRNAs have a CCA sequence at their 3ʹ terminus. 
C)  tRNAs differ in sequence only at the anticodon. 
D)  There are several modified bases present in mature tRNAs. 
A)  tRNAs are approximately 70-80 bases long and form a cloverleaf structure. 
B)  All tRNAs have a CCA sequence at their 3ʹ terminus. 
C)  tRNAs differ in sequence only at the anticodon. 
D)  There are several modified bases present in mature tRNAs.

Question 20

In translation, mRNAs are read in the _______ direction, and polypeptide chains are synthesized from the _______ ends.

Accepted Answer

A)  5ʹ to 3ʹ; carboxyl to the amino 
B)  5ʹ to 3ʹ; amino to the carboxyl 
C)  3ʹ to 5ʹ; carboxyl to the amino 
D)  3ʹ to 5ʹ; amino to the carboxyl 
A)  5ʹ to 3ʹ; carboxyl to the amino 
B)  5ʹ to 3ʹ; amino to the carboxyl 
C)  3ʹ to 5ʹ; carboxyl to the amino 
D)  3ʹ to 5ʹ; amino to the carboxyl

Eukaryotic mRNAs have a 7-methylguanosine cap on their 3ʹ end.

Some chaperones were originally known as heat-shock proteins because they are expressed in cells subjected to high temperatures and facilitate the refolding of denatured proteins.

What would happen in a bacterium in which the Shine-Dalgarno sequence was mutated?

What function does covalent modification of proteins serve in the cell that proteolysis cannot?

Glycosylphosphatidylinositol (or GPI) anchors are found

What is allosteric regulation of a protein?

Translation can be regulated by proteins that bind to the 3ʹ untranslated regions of mRNAs.

The first step in the initiation of protein synthesis is the binding of _ to the _.

Many chaperones are called heat-shock proteins because they

The enzyme protein disulfide isomerase, which facilitates breakage and reformation of disulfide bonds, is located primarily in the

An 80S eukaryotic ribosome is made up of one large 50S subunit and one small 30S subunit.

Translation is initiated by the binding of the methionyl tRNA and the mRNA to the _______ subunit, after which the other subunit joins the complex.

Which statement is true and provides evidence that a certain component of the ribosome catalyzes protein synthesis?

Protein phosphatases

Experimentally you measure the number of mRNAs being processed from a single gene at 40 copies per minute, yet based on the rate at which ribosomes scan, there should only be about three copies per minute. How might this be explained?

A proteasome is a

Translation always occurs on which of the following structures?

Which statement regarding tRNAs is false?

In translation, mRNAs are read in the _ direction, and polypeptide chains are synthesized from the _ ends.

An Overview of Cells and Cell Research

Molecules and Membranes

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Transcriptional Regulation and Epigenetics

The Nucleus

Protein Sorting and Transport

Mitochondria, Chloroplasts, and Peroxisomes

The Cytoskeleton and Cell Movement

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

Cell Signaling

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters

Exam 10: Protein Synthesis, Processing, and Regulation

Eukaryotic mRNAs have a 7-methylguanosine cap on their 3ʹ end.

Some chaperones were originally known as heat-shock proteins because they are expressed in cells subjected to high temperatures and facilitate the refolding of denatured proteins.

What would happen in a bacterium in which the Shine-Dalgarno sequence was mutated?

What function does covalent modification of proteins serve in the cell that proteolysis cannot?

Glycosylphosphatidylinositol (or GPI) anchors are found

What is allosteric regulation of a protein?

Translation can be regulated by proteins that bind to the 3ʹ untranslated regions of mRNAs.

The first step in the initiation of protein synthesis is the binding of _______ to the _______.

Many chaperones are called heat-shock proteins because they

The enzyme protein disulfide isomerase, which facilitates breakage and reformation of disulfide bonds, is located primarily in the

An 80S eukaryotic ribosome is made up of one large 50S subunit and one small 30S subunit.

Translation is initiated by the binding of the methionyl tRNA and the mRNA to the _______ subunit, after which the other subunit joins the complex.

Which statement is true and provides evidence that a certain component of the ribosome catalyzes protein synthesis?

Protein phosphatases

Experimentally you measure the number of mRNAs being processed from a single gene at 40 copies per minute, yet based on the rate at which ribosomes scan, there should only be about three copies per minute. How might this be explained?

A proteasome is a

Translation always occurs on which of the following structures?

Which statement regarding tRNAs is false?

In translation, mRNAs are read in the _______ direction, and polypeptide chains are synthesized from the _______ ends.

An Overview of Cells and Cell Research

Molecules and Membranes

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Transcriptional Regulation and Epigenetics

The Nucleus

Protein Sorting and Transport

Mitochondria, Chloroplasts, and Peroxisomes

The Cytoskeleton and Cell Movement

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

Cell Signaling

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters

The first step in the initiation of protein synthesis is the binding of _ to the _.

In translation, mRNAs are read in the _ direction, and polypeptide chains are synthesized from the _ ends.