Q: What is a peptide linkage? Choose two amino acids from Fig
What is a peptide linkage? Choose two amino acids from Fig. 21.2 and draw structures for the two dipeptides those amino acids are capable of forming, circling the peptide linkage in each. From figure...
See AnswerQ: Proton NMR spectroscopy provides evidence for the restricted rotation of a peptide
Proton NMR spectroscopy provides evidence for the restricted rotation of a peptide bond. For example, N,N dimethylformamide exhibits three signals in its proton NMR spectrum at room temperature. Two...
See AnswerQ: We saw in Section 25.6 that DCC can be used
We saw in Section 25.6 that DCC can be used to form a peptide bond. We explored the mechanism, and we saw that DCC activates the COOH group so that it readily undergoes nucleophilic acyl substitution....
See AnswerQ: A peptide with 22 amino acid residues is treated with trypsin to
A peptide with 22 amino acid residues is treated with trypsin to give four fragments, while treatment with chymotrypsin yields six fragments. Identify the sequence of the 22 amino acid residues in the...
See AnswerQ: Consider the structure of the following cyclic octapeptide. Would cleavage of
Consider the structure of the following cyclic octapeptide. Would cleavage of this peptide with trypsin produce different fragments than cleavage with chymotrypsin? Explain.
See AnswerQ: Draw a bond-line structure of the peptide that corresponds with
Draw a bond-line structure of the peptide that corresponds with the following sequence of amino acid residues and identify the N terminus and C terminus: Trp-Val-Ser-Met-Gly-Glu
See AnswerQ: Identify the N-terminal residue of a peptide that yields the
Identify the N-terminal residue of a peptide that yields the following PTH derivative upon Edman degradation:
See AnswerQ: Glucagon is a peptide hormone produced by the pancreas that, with
Glucagon is a peptide hormone produced by the pancreas that, with insulin, regulates blood glucose levels. Glucagon is comprised of 29 amino acid residues. Treatment with trypsin yields four fragments...
See AnswerQ: When the N terminus of a peptide is acetylated, the peptide
When the N terminus of a peptide is acetylated, the peptide derivative that is formed is unreactive toward phenyl isothiocyanate. Explain.
See AnswerQ: How many different sequences of mRNA could encode a peptide with the
How many different sequences of mRNA could encode a peptide with the sequence proline-glycine-methionine-serine?
See AnswerQ: As shown in Figure 14.12, four regions within the
As shown in Figure 14.12, four regions within the trpL mRNA can form stem-loops. Let’s suppose that mutations have been previously identified that prevent the ability of a particular...
See AnswerQ: The combination of a 3–4 stem-loop and a
The combination of a 3–4 stem-loop and a U-rich attenuator in the trp operon (see Figure 14.12) is an example of a Ï-independent terminator. The function of &I...
See AnswerQ: Mutations in tRNA genes can create tRNAs that recognize stop codons.
Mutations in tRNA genes can create tRNAs that recognize stop codons. Because stop codons are sometimes called nonsense codons, these types of mutations that affect tRNAs are called nonsense suppressor...
See AnswerQ: In the procedure in Figure 22.1, why was it
In the procedure in Figure 22.1, why was it necessary to link the coding sequence for the A or B chains to the sequence for β-galactosidase? How were the A or B chains separate...
See AnswerQ: Explain how tandem mass spectroscopy is used to determine the sequence of
Explain how tandem mass spectroscopy is used to determine the sequence of a peptide. Once a peptide sequence is known, how is this information used to determine the sequence of the entire protein?
See AnswerQ: What type of bond is the peptide bond? Explain why the
What type of bond is the peptide bond? Explain why the peptide bond is rigid.
See AnswerQ: Draw the resonance hybrids that represent the peptide bond.
Draw the resonance hybrids that represent the peptide bond.
See AnswerQ: Write a balanced equation showing peptide bond formation between threonine and aspartate
Write a balanced equation showing peptide bond formation between threonine and aspartate.
See AnswerQ: Draw the structural formula of the peptide trp-val-lys
Draw the structural formula of the peptide trp-val-lys-ala-ser. Show which bonds would be cleaved by trypsin, chymotrypsin, and elastase.
See AnswerQ: Repeat Question 19.95 for the peptide trp-pro-
Repeat Question 19.95 for the peptide trp-pro-gly-tyr. Question 19.95: Draw the complete structural formula for the peptide tyrlys- ala-phe. Show which bond would be broken when this peptide is reac...
See AnswerQ: What peptide sequence would be formed from the mRNA. 59
What peptide sequence would be formed from the mRNA. 59-AUGUGUAGUGACCAACCGAUUUCACUGUGA-39?
See AnswerQ: The main function of a DNA molecule is to ______. a
The main function of a DNA molecule is to ______. a. store heritable information b. carry a translatable message c. form peptide bonds between amino acids
See AnswerQ: The main function of an mRNA molecule is to ______. a
The main function of an mRNA molecule is to ______. a. store heritable information b. carry a translatable message c. form peptide bonds between amino acids
See AnswerQ: 1. A ______ is synthesized from cholesterol and can diffuse across
1. A ______ is synthesized from cholesterol and can diffuse across the plasma membrane. a. steroid hormone b. protein hormone c. peptide hormone d. hormone receptor 2. In adults, too much ______ can...
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