Bio101/Chem111 Homework Problems #2 1. Draw the peptide KTQHV, write the sequence using 3-letter abbreviation for the amino acids, and identify: a. The N- and C-termini. b. Every a-carbon of the sequence, by labeling them with "a". c. All peptide bonds. d. Hydrogen bond donors and acceptors in the polar side chains. e. Covalent bonds that correspond to the backbone phi (D) and psi (4) angles f. Ionizable R-groups of amino acids in this sequence (circle them). i. Choose one ionizable group and draw it at pH 1, pH 7, and pH 14 and indicate the approximate net charge at each pH. ii. What fraction of His residues are charged at pH=5.8?

Bio101/Chem111 Homework Problems #2 1. Draw the peptide KTQHV, write the sequence using 3-letter abbreviation for the amino acids, and identify: a. The N- and C-termini. b. Every a-carbon of the sequence, by labeling them with "a". c. All peptide bonds. d. Hydrogen bond donors and acceptors in the polar side chains. e. Covalent bonds that correspond to the backbone phi (D) and psi (4) angles f. Ionizable R-groups of amino acids in this sequence (circle them). i. Choose one ionizable group and draw it at pH 1, pH 7, and pH 14 and indicate the approximate net charge at each pH. ii. What fraction of His residues are charged at pH=5.8?

Chemistry: Principles and Reactions

8th Edition

ISBN:9781305079373

Author:William L. Masterton, Cecile N. Hurley

Publisher:William L. Masterton, Cecile N. Hurley

Chapter23: Organic Polymers, Natural And Synthetic

Section: Chapter Questions

Problem 31QAP: On complete hydrolysis, a polypeptide gives two alanine, one leucine, one methionine, one...

See similar textbooks

Similar questions

For the tripeptide GlyAlaCys a. What amino acid is located at the peptides N-terminal end? b. What amino acid is located at the peptides C-terminal end? c. How many peptide bonds are present? d. How many amide linkages are present?
Using both three- and one-letter codes for amino acids, write the structures of all possible peptides containing the following amino acids: (a) Val, Ser, Leu (b) Ser, Leu2, Pro
A 1.00-mg sample of a pure protein yielded on hydrolysis 0.0165 mg of leucine and 0.0248 mg of isoleucine. What is the minimum possible molar mass of the protein? (MMleucine=MMisoleucine=131g/mol)
22-35 Why is histidine considered a basic amino acid when the pKa of its side chain is 6.0?
On complete hydrolysis, a polypeptide gives two alanine, one leucine, one methionine, one phenylalanine, and one valine residue. Partial hydrolysis gives the following fragments: Ala-Phe, Leu-Met, Val-Ala, Phe-Leu. It is known that the first amino acid in the sequence is valine and the last one is methionine. What is the complete sequence of amino acids?
22-42 (a) How many atoms of the peptide bond lie in the same plane? (b) Which atoms are they?
How many of the -amino acids shown in Table 26-1 contain aromatic rings? How many contain sulfur? How many contain alcohols? How many contain hydrocarbon side chains?
Draw a segment of the backbone of a protein that is long enough for three peptide linkages to be present.
2. Diagram the peptide ACKE at physiological then answer questions a- h. a. Circle one peptide bond. b. Box one alpha carbon in this peptide c. How many peptide bonds are present in this peptide? d. Which amino acid is at the C-terminus? e. Which amino acid is at the N-terminus? f. Label one omega, one phi and one psi bond angle. g. Sketch in one peptide plane. h. Calculate the charge of the peptide at pH 13.
Consider the structure of the peptide below and answer the questions that follow
Identify the name of the amino acid and classify it based on: a. chirality b. configuration c. r-group (side chain) d. acidic-basic property e. polarity f. essentiality
NH₂ 4. Draw the following peptides. You may use Kelule Formula or the Line-bond (or skeletal) Formula: a. Alanine-Glycine-Serine b. Phe-Tyr-Trp C. KMH 5. Briefly describe the following: a. Primary Structure b. Secondary Structure NH₂ c. Tertiary Structure d. Quaternary Structure 6. APPLICATION: For the following items, do some literature search to answer them: a. Sickle cell anemia is one of the disease that is caused by defects in protein structure. Briefly discuss the biochemical basis of sickle cell anemia. What level of protein structure does it affect? b. Thalassemias are caused by genetic defects that impair the synthesis hemoglobin causing anemia symptoms to people affected by it. Briefly discuss the biochemical basis of thalassemias. What level of protein structure does it affect?