Protein Structure and Translation Launchpad
How many aminoacyl-tRNA synthetase enzymes must be present in cells to properly synthesize proteins? - 20, one for each amino acid - 64, one for each possible codon - 3, one for each base in a codon - 4, one for each base in the mRNA
20, one for each amino acid
Assuming A-U and G-C pairing between the anticodon and the codon, what anticodon in tRNAMet would pair with the codon 5′-AUG-3′? - 5′-UAC-3′ - 5′-ATG-3′ - 5′-GUA-3′ - 5′-CAU-3′
5′-CAU-3′ Two paired strands of nucleic acids should be antiparallel, so G on the 3′ end of the codon should be paired with C on the 5′ end of anticodon; the middle U with A; and A on the 5′ end of the codon with U on the 3′ end of the anticodon.
Enzymatic catalysis of the peptide bond between the growing polypeptide and the next incoming amino acid takes place in which binding site? P site combined A and P sites A site E site
A site
The interactions between amino acids are major factors in determining the shape of a protein. These interactions can be affected by the environment surrounding a protein. Which factor would have an effect on the shape of a protein? - whether the other molecules in the environment are predominantly hydrophilic or hydrophobic - the pH of the environment - the concentrations of ions present in the environment - the temperature of the environment. - All of these choices are correct.
All of these choices are correct.
Which step occurs in the A site of the ribosome during translation? - The tRNA carrying the growing polypeptide moves to this site as the ribosome slides to the next codon. - An incoming charged tRNA binds to this site. - None of the other answer options is correct. - An uncharged tRNA is ejected from this site as the ribosome slides to the next codon.
An incoming charged tRNA binds to this site.
Which of the answer choices occurs in the E site of the ribosome during translation? - An uncharged tRNA is ejected from this site as the ribosome slides to the next codon. - The tRNA carrying the growing polypeptide moves to this site as the ribosome slides to the next codon. - None of the other answer options is correct. - An incoming charged tRNA binds to this site.
An uncharged tRNA is ejected from this site as the ribosome slides to the next codon.
What feature or structure in the simulation indicates that this is eukaryotic translation? - The small ribosomal subunit binds to the 5' end of the mRNA and scans to the nearest AUG codon. - The small ribosomal subunit binds to a Shine-Dalgarno sequence in the mRNA and locates a nearby AUG codon. - The first incorporated amino acid is methionine.
The small ribosomal subunit binds to the 5' end of the mRNA and scans to the nearest AUG codon.
Which step occurs in the P site of the ribosome during translation? - The tRNA carrying the growing polypeptide moves to this site as the ribosome slides to the next codon. - An incoming charged tRNA binds to this site. - None of the other answer options is correct. - An uncharged tRNA is ejected from this site as the ribosome slides to the next codon.
The tRNA carrying the growing polypeptide moves to this site as the ribosome slides to the next codon.
Which of the following is the actual event that translates the language of nucleic acids (the sequence of bases, A, T (U), C, and G) to the language of proteins (determining which amino acid will be added to the polypeptide)? - establishing the correct reading frame by the ribosome - catalysis of a new peptide bond from the growing polypeptide to the next amino acid - release of the finished polypeptide at the stop codon - attachment of the appropriate amino acid to the tRNA by aminoacyl tRNA synthetase - binding of charged tRNA to the ribosome A site
attachment of the appropriate amino acid to the tRNA by aminoacyl tRNA synthetase
Proteins that prevent inappropriate folding of newly synthesized proteins are called: enzymes. synthetases. chaperones. polymerases. ribosomes.
chaperones
How is the amino acid held on the charged tRNA? - It can be a combination of all bond types. - covalent bond - hydrogen bonds
covalent bond
The unfolding of a protein by heat or chemical treatment is referred to as: uncoupling. denaturation. disaggregation. depolymerization. hydrolysis.
denaturation
An area of a polypeptide that bends in a particular way, relatively independent of the rest of the molecule, is a folding: domain. segment. exon. region. lariat.
domain
In a protein-coding region of DNA, any mutation that replaces a single nucleotide for another will replace any amino acid with any other amino acid. false true
false
Most proteins retain metabolic activity when denatured. false true
false
Protein families contain proteins with identical primary, secondary, and tertiary structures. false true
false
When a charged tRNA is about to bind to the vacant A site of a ribosome, where is the growing polypeptide? - in the E site - in the P site - in the A site - The polypeptide is equally likely to be in any of the three sites.
in the P site
The ribosome ______ subunit has _______ binding sites for tRNA molecules. large; four large; two small; two small; three large; three
large; three
In a population of organisms, beneficial and harmful random mutations are retained or eliminated through the process of: translation. selection. expression. conservation. folding.
selection
Ribosomes in prokaryotes and eukaryotes are: - identical in structure and translate using the same genetic code. - similar in structure and translate using the same genetic codes. - identical in structure but translate using different genetic codes. - similar in structure and translate using different genetic code.
similar in structure and translate using the same genetic codes.
The fully folded structure of a functional protein composed of a single polypeptide chain is referred to as: secondary. primary. quaternary. tertiary.
tertiary
Binding sites for tRNA are located in: - the small ribosomal subunit. - neither ribosomal subunit. - the large ribosomal subunit. - both ribosomal subunits. Score: 1 of 1
the large ribosomal subunit.
