Chapter 10: DNA to Protein – Flashcards

During which stage would you expect promoters to play a role? a. Initiation of transcription b. Elongation of transcription c. Termination of transcription d. Initiation of translation e. Elongation of translation

If the third nucleotide in the codon 5 -AAA-3 is changed from A to G (both AAA and AAG are codons for Lysine), a _______ mutation will occur and the result will be _______. a. silent; no effect b. nonsense; no effect c. missense; formation of a stop codon d. frame-shift; no effect e. nonsense; formation of a stop codon

Posttranslational alterations of proteins a. do not affect the activity of an enzyme. b. do not include the addition of phosphate groups. c. do not include the addition of polysaccharides to proteins. d. do not include the cleavage of signal sequences. e. may include the addition of polysaccharides to proteins.

Consider the typical multicellular eukaryote. In comparison with the DNA made in DNA replication, transcribed mRNAs are made in _______ copies, are _______ error prone, and do not last as long. a. more; less b. more; more c. more; similarly d. fewer; more e. fewer; less

During protein synthesis, ribosomes a. translate mRNA into DNA. b. transcribe mRNA to proteins. c. translate mRNA into tRNA. d. translate mRNA into polypeptides. e. transcribe DNA into mRNA.

An mRNA molecule has 540 codons. It must have at least _______ nucleotides. a. 180 b. 270 c. 540 d. 1,080 e. 1,620

The three codons in the genetic code that do not specify amino acids are called a. missense codons. b. start codons. c. stop codons. d. promoters. e. initiator codons.

The adapters that allow translation of the four-letter nucleic acid language into the 20-letter protein language are called a. aminoacyl tRNA synthetases. b. transfer RNAs. c. ribosomal RNAs. d. messenger RNAs. e. ribosomes.

The binding of snRNPs to consensus sequences is important in a. transport of mRNA to the cytoplasm. b. transport of mRNA to the nucleus. c. mRNA stability. d. ensuring that introns are properly spliced out. e. formation of the 5 cap.

Protein kinases are involved in the _______ of other proteins. a. kinetics b. glycosylation c. phosphorylation d. proteolysis e. exonuclease digestion

What decodes the information present in mRNA? a. mRNA itself b. rRNA c. tRNA d. Aminoacyl-tRNA synthetases e. Small nuclear ribonucleoprotein particles

Promoters are made of a. proteins. b. carbohydrates. c. lipids. d. nucleic acids. e. amino acids.

Which part of the tRNA base-pairs with the codon in the mRNA? a. The 3 end, where the amino acid is covalently attached b. The 5 end c. The anticodon d. The start codon e. The promoter

What are the intracellular destinations of the following proteins: DNA polymerase; pyruvate kinase; rubisco; citrate synthase? a. Nucleus; mitochondrion; chloroplast; cytoplasm b. Nucleus; cytoplasm; chloroplast; mitochondrion c. Cytoplasm; chloroplast; mitochondrion; nucleus d. Cytoplasm; chloroplast; nucleus; mitochondrion e. Mitochondrion; chloroplast; nucleus; cytoplasm

Which change will most likely result in a frameshift mutation? a. A point mutation from A to C b. A point mutation from C to G c. The deletion of 6 nucleotides d. The insertion of 7 nucleotides e. The insertion of 24 nucleotides

Which of the following statements about RNA polymerase is false? a. It synthesizes mRNA in a 5 -to-3 direction, reading the DNA strand 3 to 5 . b. It synthesizes mRNA in a 3 -to-5 direction, reading the DNA strand 5 to 3 . c. It binds at the promoter and unwinds the DNA. d. It does not require a primer to initiate transcription. e. It uses only one strand of DNA as a template for synthesizing RNA.

A charged tRNA and a small ribosomal subunit are both bound to the mRNA. These form the a. initiation complex in transcription. b. initiation complex in translation. c. polysome. d. spliceosome. e. peroxisome.

UAU and UAC both code for tyrosine. A change from UAU to UAC would thus be a _______ mutation; a change from UAU to UAG would be a _______ mutation. a. silent; missense b. nonsense; silent c. frame-shift; missense d. silent; nonsense e. nonsense; frame-shift

The mRNA codon for leucine is 5 -UUG-3 , and the tRNA anticodon is a. 5 -UUG-3 . b. 5 -GUU-3 . c. 5 -TTC-3 . d. 5 -AAC-3 . e. 5 -CAA-3 .

Ribosomes a. are not found in prokaryotes. b. carry genetic information. c. carry out translation. d. contain RNA only. e. have no role in the fidelity of mRNA and tRNA interactions.

A protein destined for a lysosome carries a signal peptide for the a. lysosome. b. mitochondria. c. nucleus. d. rough ER. e. plasma membrane.

Which molecule or structure has peptidyl transferase activity? a. mRNA b. tRNA c. The small subunit of the ribosome d. The large subunit of the ribosome e. DNA

Which component is required for the initiation of transcription? a. The start codon AUG b. Promoter DNA sequence c. Ribonucleoside triphosphates d. Terminator DNA sequence e. DNA polymerase

What would happen if a mutation occurred in DNA such that the second codon of the resulting mRNA were changed from UGG to UAG? a. Translation would continue and the second amino acid would be the same. b. Nothing. The ribosome would skip that codon and translation would continue. c. Translation would continue, but the reading frame of the ribosome would be shifted. d. Translation would stop at the second codon, and no functional protein would be made. e. Translation would continue, but the second amino acid in the protein would be different.

Proteins that will go to different locations will likely have different _______ sequences. a. address b. messenger c. signal d. transport e. utility

What structure or molecules bring tRNA and mRNA together? a. Aminoacyl-tRNA synthase b. Ribosome c. Peptidyl transferase d. RNA polymerase e. Small nuclear ribonucleoprotein particles

Which statement about pre-mRNA splicing is false? a. It removes introns. b. It is performed by small nuclear ribonucleoprotein particles (snRNPs). c. It is common in prokaryotes. d. It is directed by consensus sequences. e. It shortens the RNA molecule.

Which statement about tRNAs is false? a. Specific enzymes bind amino acids to their corresponding tRNAs. b. They have an anticodon at their 5 end and an amino acid attachment site at their 3 end. c. They interact with mRNA. d. They interact with ribosomes. e. ATP is required for the charging of tRNAs with amino acids.

AUG is _______ codon. a. a stop b. the start c. a redundant d. an ambiguous e. a silent

Transcription is the process of a. synthesizing a DNA molecule from an RNA template. b. assembling ribonucleoside triphosphates into an RNA molecule without a template. c. synthesizing an RNA molecule using a DNA template. d. synthesizing a protein using information from a messenger RNA. e. replicating a single-stranded DNA molecule.

Put the following four steps of eukaryotic gene expression in order, from beginning to end. (1) Pre-mRNA is processed to make mRNA. (2) Ribosomes translate the mRNA sequence to make proteins. (3) mRNA is transported to the cytoplasm. (4) DNA is used as a template to make pre-mRNA. a. 1; 4; 3; 2 b. 4; 3; 1; 2 c. 4; 1; 3; 2 d. 4; 1; 2; 3 e. 1; 2; 4; 3 0.5 points Save Answer

Which types of molecules are contained in a spliceosome? a. DNA and RNA b. DNA and protein c. RNA and protein d. RNA and lipid e. Protein and lipid

A point mutation results in a stop codon. The most likely result is a _______ mutation. a. missense b. frameshift c. nonsense d. silent e. dominant

The enzymes that charge the tRNA molecules with appropriate amino acids are a. peptidyl transferases. b. amino tRNA chargeatases. c. transcriptases. d. aminoacyl-tRNA synthases. e. RNA polymerases.

Why did the original one-gene, one-enzyme hypothesis have to be modified? a. Some RNAs have catalytic activity. b. Not all proteins are coded by genes. c. Some enzymes are made up of more than one polypeptide. d. All genes code for multiple enzymes. e. Not all enzymes are coded for by genes.

Translation is the process by which information in _______ is propagated into information in _______. a. DNA; RNA b. DNA; protein c. RNA; DNA d. RNA; protein e. protein; RNA 0.5 points Save Answer

A stretch of 150 nucleotides in a coding region would code for _______ codons. a. 30 b. 50 c. 150 d. 450 e. 750

During transcription, what molecule unwinds the DNA? a. Transcription factor(s) b. Initiation factor(s) c. RNA polymerase d. RNA helicase e. No molecules are needed; the DNA unwinds itself.

The process of gene expression involves two steps in which _______ is transcribed into _______, which is (are) translated into _______. a. a gene; polypeptides; a gene product b. protein; DNA; RNA c. DNA; mRNA; tRNA d. DNA; RNA; protein e. RNA; DNA; protein

A tRNA that has given up its amino acid could be located on _______ of the ribosome. a. only the A site b. either the A site or the P site c. only the P site d. either the A site or the E site e. only the E site

A mutation of a sigma factor in a bacterium would most likely affect a. the rate at which transcription is initiated. b. the rate at which transcription elongation occurs. c. the frequency of errors in transcription. d. the types of modifications done to RNA during processing. e. the rate at which translation occurs.

Each mRNA codon binds to _______ tRNA(s). a. only one b. one or two c. exactly two d. exactly three e. at least three

Termination of translation requires a. a termination signal, RNA polymerase, and a release factor. b. a release factor, initiator tRNA, and ribosomes. c. initiation factors, the small subunit of the ribosome, and mRNA. d. elongation factors and charged tRNAs. e. a stop codon positioned at the A site of the ribosome and a release factor.

There are _______ different types of codons in the genetic code, and each codon is _______ nucleotides long. a. 16; 2 b. 16; 3 c. 16; 4 d. 64; 2 e. 64; 3

In what way does RNA polymerase differ from DNA polymerase? a. RNA polymerase does not require a primer. b. DNA polymerase does not require a primer. c. DNA polymerase is processive, but RNA polymerase is not. d. RNA polymerase is processive, but DNA polymerase is not. e. RNA polymerase and DNA polymerase differ only in the type of nucleic acid they synthesize.

Consensus sequences involved in splicing are located a. in the middle of introns. b. in the middle of exons. c. at the boundaries of introns and exons. d. at the 5 cap. e. at the poly-A tail.

Cells have substantially _______ different tRNAs than codons, due to the phenomenon called _______. a. more; the fidelity function b. more; splicing c. more; wobble d. fewer; the fidelity function e. fewer; wobble

The tRNA moves between three sites along the ribosome: A, E, and P. In chronological order, what is the pattern of residence of a given tRNA molecule at those sites? a. A, then E, then P b. A, then P, then E c. E, then P, then A d. P, then A, then E e. P, then E, then A

Proteins are synthesized from the _______ in the _______ direction along the mRNA. a. N terminus to C terminus; 5 to 3 b. C terminus to N terminus; 5 to 3 c. C terminus to N terminus; 3 to 5 d. N terminus to C terminus; 3 to 5 e. N terminus to N terminus; 5 to 3

Stop codons a. enter only the A site. b. enter the A and the E sites. c. enter the A and the P sites. d. enter the A, P, and E sites. e. do not enter any of the spots on the ribosome.

After processing in the ER, a protein inappropriately moves back into the ER through the membrane because its signal sequence is still attached. This is a failure of a. proteolysis. b. glycosylation. c. phosphorylation. d. the fidelity function. e. translation.

Protein kinases are involved in the _______ of other proteins. a. kinetics b. glycosylation c. phosphorylation d. proteolysis e. exonuclease digestion

Poly A tails a. are added after transcription. b. are encoded by a sequence of thymines in the DNA. c. are found in all RNAs. d. have no function. e. are removed during RNA processing.

If a 5 -to-3 template strand of DNA has the sequence GTACA...ATAGCA, what would be the sequence of the resulting transcribed RNA? a. 5 -GTACA...ATAGCA-3 b. 3 -GTACA...ATAGCA-5 c. 5 -GUACA...AUAGCA-3 d. 3 -CATGT...TATCGT-5 e. 3 -CAUGU...UAUCGU-5

Translation of messenger RNA into protein occurs in a _______ direction and from the _______ terminus to the _______ terminus. a. 3 -to-5 ; N; C b. 5 -to-3 ; N; C c. 3 -to-5 ; C; N d. 5 -to-3 ; C; N e. 3 -to-5 ; C; C

The anticodon is a. always present on a tRNA and is located at the 5 end. b. always present on a tRNA and is located in the middle of the sequence. c. always present on a tRNA and is located at the 3 end of the sequence. d. added to the tRNA by aminoacyl-tRNA synthetase. e. added to the tRNA by enzymes not yet known.