Chapter 7- From DNA to Protein

Some antibiotics can be taken in high doses because they disrupt bacterial, but not eukaryotic, protein synthesis. A. True B. False

A

Some genes do not encode proteins, but instead encode functional RNA. A. True B. False

A

The assembly of general transcription factors to a eukaryotic promoter begins at what site in a promoter? A. The TATA box B. The GAGA box C. The TFIID box D. The assembly box

A

To begin transcription, RNA polymerase recognizes nucleotide sequences in what region of the DNA? A. Promoter region B. Templateregion C. G-C rich region D. Terminator region

A

Unlike the coding sequence of an exon, most of the nucleotide sequence of an intron is unimportant. A. True B. False

A

Amino acids are attached to their tRNA molecules by: A. aminoacyl-tRNAsynthetase. B. peptide bond formation. C. RNA ligase. D. aminoacyl hydroxylases.

A

An RNA molecule can fold into complex three-dimensional shapes because: A. it is a single-stranded. B. it isdouble-stranded. C. it contains the base uracil rather than thymine.

A

At what site do all charged tRNAs (with the exception of the initiator tRNA) first bind on the ribosome? A. A site B. P site C. E site

A

Eukaryotic mRNAs: A. are translated after they are exported from the nucleus. B. are transcribed and translated simultaneously. C. must be folded into the correct three-dimensional shape before they can be translated. D. are processed in the same way as prokaryotic mRNAs.

A

How do proteases act? A. By hydrolyzing peptide bonds between amino acids in a protein B. By forming peptide bonds between amino acids in a protein C. By folding polypeptides into correct three-dimensional structures

A

In bacteria, most protein-coding genes lack introns. A. True B. False

A

RNA polymerases can start an RNA chain without a primer. A. True B. False

A

RNA polymerases join nucleotides through what kind of bond? A. Phosphodiester B. Hydrogen C. Peptide D. Glycosidic

A

What determines the nucleotide sequence of an RNA strand? A. Complementary base pairing with the DNA template during transcription B. The amino acid sequence in a protein C. The diversity of nucleotides accessible to RNA polymerase to use in transcription

A

What is a polyribosome? A. A cluster of ribosomes translating the same mRNA, but positioned at different sites along the mRNA . B. A ribosome that is in the middle of translating an mRNA into a polypeptide. C. A ribosome translating a polycistronic mRNA molecule.

A

What is the term for an RNA molecule that possesses catalytic activity? A. Enzyme B. Ribozyme C. Catalyst

B

At which site on the DNA of a gene does RNA polymerase release its newly made RNA? A. Promoter B. Template C. Stop codon D. Terminator

D

All proteins are fully functional upon leaving the ribosome. A. True B. False

B

An RNA chain elongates in what direction? A. 3′ to 5′ B. 5′ to 3′

B

At what site does the charged initiator tRNA first bind on the ribosome? A. A site B. P site C. E site

B

At which end of an mRNA molecule do ribosomal subunits first bind? A. The 3′ end B. The 5′ end

B

Bacterial mRNAs: A. are translated after they are exported from the nucleus. B. are transcribed and translated simultaneously. C. must be folded into the correct three-dimensional shape before they can be translated. D. are processed in the same way as eukaryotic mRNAs.

B

Each nucleotide in an mRNA encodes one amino acid in a protein. A. True B. False

B

How many nucleotides are necessary to specify a single amino acid? A. 1 B. 3 C. 20 D. It depends on the amino acid.

B

In eukaryotes, what must assemble at a promoter before RNA polymerase can transcribe a gene? A. Nucleotides required in transcription B. General transcription factors C. Sigma factor D. An RNA primer

B

In principle, how many reading frames in RNA can potentially be translated into proteins? A. 1 B. 3 C. 4 D. 6

B

Introns are removed by: A. RNase. B. RNA splicing in the nucleus. C. RNA splicing in the cytoplasm. D. RNA polymerase III.

B

The translation of an mRNA begins at the start codon: A. AGU. B. AUG. C. UAG. D. ATG.

B

Where in a cell are most damaged proteins broken down? A. Peroxisomes B. Cytosol C. Golgi apparatus D. Endoplasmic reticulum

B

Which of the following statements is NOT true? A. The different lifetimes of eukaryotic mRNAs are controlled in part by nucleotide sequences in the mRNA itself. B. In a eukaryotic mRNA, the poly-A tail promotes degradation of the molecule. C. Many eukaryotic mRNAs have a longer lifetime than bacterial mRNAs. D. The longer the lifetime of an mRNA, the more protein can be produced from it.

B

Which part of a protein is synthesized by a ribosome first? A. The C-terminus B. The N-terminus

B

Which statement is false? A. The genetic code contains three stop codons. B. Stop codons are not recognized by a tRNA. C. Release factors bind to stop codons.

B

Which sugar cannot be readily made from formaldehyde in experiments simulating conditions on primitive Earth? A. Ribose B. Deoxyribose C. Glucose

B

Which type of molecule has the potential to perform the catalytic action of reproducing itself? A. DNA B. RNA C. Protein D. Polysaccharides

B

All of the RNA in a cell is made by what process? A. Replication B. Hydrolysis C. Transcription D. Translation

C

An RNA message is decoded by: A. ribozymes. B. RNA Polymerases. C. ribosomes. D. the nucleus.

C

Compared to the error rate of DNA polymerase (1 error in 107 nucleotides), the error rate of RNA polymerases is: A. much less. B. about the same. C. much greater.

C

In RNA, which base pairs with the base A? A. C B. G C. U D. T

C

In eukaryotes, the initiator tRNA always carries which amino acid? A. Glycine B. Alanine C. Methionine D. Lysine

C

In eukaryotes, which parts of a gene are transcribed into RNA? A. Introns B. Exons C. Introns and exons

C

Proteasomes act primarily on proteins that have been marked for destruction by the covalent attachment of which small protein? A. Protease B. Histone C. Ubiquitin D. Termination factor

C

What energy drives the transcription reaction forward? A. The release of high-energy electrons from cofactors associated with RNA polymerase B. The energy from ATP formation C. The hydrolysis of high-energy bonds of ribonucleoside triphosphates during elongation

C

What is NOT true about codons in mRNA molecules? A. Codons in mRNAs bind to complementary anticodons in tRNAs. B. Some codons do not code for amino acids. C. Some codons code for more than one amino acid. D. In some cases, several different codons code for the same amino acid.

C

What is the "central dogma"? A. Genetic information flows from RNA to DNA to protein. B. Genetic information flows from RNA to protein to DNA. C. Genetic information flows from DNA to RNA to protein. D. Genetic information flows from DNA to protein to RNA. E. Genetic information flows from protein to RNA to DNA. F. Genetic information flows from protein to DNA to RNA.

C

What is the name of the subunit of bacterial RNA polymerase that recognizes the promoter of a gene? A. /Alpha helix B. /Beta polymerase C. Sigma factor

C

Which biochemical reaction is catalyzed by a ribozyme? A. Glycosidic bond formation in polysaccharide synthesis B. DNA polymerization during DNA replication C. Peptide bond formation in protein synthesis D. Peptide bond hydrolysis by proteases

C

Which of the following does not increase the stability of eukaryotic mRNAs? A. A 5′-end cap B. A poly-A tail C. An intron

C

Which of the following is well accepted in the scientific community? A. Introns evolved early in life forms, and only later did prokaryotes lose their introns. B. Introns evolved later in eukaryotes, which is why they don't appear in prokaryotes. C. Neither-the evolution of introns is still a topic of debate.

C

Within the ribosome, the formation of peptide bonds is catalyzed by: A. aminoacyl-tRNAsynthetase. B. the tRNA itself. C. an RNA molecule in the large ribosomal subunit. D. a peptidase in the small ribosomal subunit.

C

What structure is responsible for selecting and transporting only properly processed eukaryotic mRNAs into the cytoplasm? A. The spliceosome B. snRNPs C. RNA polymerase D. The nuclear pore complex E. Ribosomes

D

Which base is not present in RNA? A. A B. C C. G D. U E. T

E