Most naturally occurring amino acids have chiral centers (the asymmetric a carbon atoms)that are named (S) by the Cahn–Ingold–Prelog convention (Section 5-3). The commonnaturally occurring form of cysteine has a chiral center that is named (R), however.(a) What is the relationship between (R)-cysteine and (S)-alanine? Do they have the oppositethree-dimensional configuration (as the names might suggest) or the same configuration?(b) (S)-Alanine is an l-amino acid (Figure 24-2). Is (R)-cysteine a d-amino acid or anl-amino acid?

Most naturally occurring amino acids have chiral centers (the asymmetric a carbon atoms)that are named (S) by the Cahn–Ingold–Prelog convention (Section 5-3). The commonnaturally occurring form of cysteine has a chiral center that is named (R), however.(a) What is the relationship between (R)-cysteine and (S)-alanine? Do they have the oppositethree-dimensional configuration (as the names might suggest) or the same configuration?(b) (S)-Alanine is an l-amino acid (Figure 24-2). Is (R)-cysteine a d-amino acid or anl-amino acid?

Chemistry & Chemical Reactivity

9th Edition

ISBN:9781133949640

Author:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Publisher:John C. Kotz, Paul M. Treichel, John Townsend, David Treichel

Chapter24: Biochemistry

Section: Chapter Questions

Problem 4PS

See similar textbooks

Similar questions

The following amino acid side chain is - CHCH 3 -C CH 3 1) polar. 2) basic. 3) hydrophobic. 4) hydrophilic. 5) acidic.
You are given the structures of the amino acids alanine (Ala), methionine (Met) and threonine (Thr). to H2N CO2H H2N CO2H H2N co,H
There are four dimethylcyclopropane isomers. (a) Write three-dimensional formulas for these isomers. (b) Which of the isomers are chiral? (c) If a mixture consisting of 1 mol of each of these isomers were subjected to simple gas chromatography, how many fractions would be obtained and which compounds would each fraction contain? (d) How many of these fractions would be optically active? tod o ors brie page 10 of 17
Match the following amino acids with their chemical properties H -N-CIC- A -A ✓ B но с D VE ✓ F ✓ G / CH3 CH3 CH B H но -N-C-C- feed C но -N-C-C- H CH₂ D HO -N-CIC- 1 H CH₂ OH E но ||| -N-C-C- II H CH₂ I CH₂ CH₂ CH₂ T NH3 I. Acidic II. Nonpolar III. Polar uncharged IV, Basic + F O HO -N-C-C- H CH₂ NH₂ G но | || -N-C-C- I H CH₂ 1
Aminopropane is an achiral molecule, but 2-aminobutane is chiral. Explain.
In the box below draw the tetrahedral representation of the R enantiomer of the amino acid valine, CH3CH(CH3)CH(NH2)CO2H.
In the box below draw the tetrahedral representation of the S enantiomer of the amino acid valine, CH3CH(CH3)CH(NH2)CO,H. • Use the wedge/hash bond tools to indicate stereochemistry where it exists. Do not draw the amino acid in zwitterion form. opy aste ChemDoodle
Indicate whether each statement is true or false. (a) Thesequence of amino acids in a protein, from the amine endto the acid end, is called the primary structure of the protein.(b) Alpha helix and beta sheet structures are examplesof quaternary protein structure. (c) It is impossiblefor more than one protein to bind to another and make ahigher order structure.
3. Classify the following as a lipid, carbohydrate, or amino acid: (EOCQ 58) CH,OC(CH,)12CH, CHOC(CH,),,CH, CH,0C(CH,),CH=CH(CH,),CH, a.
Using alanine as an example, draw possible conformations of alanine in a peptide chain (Ala-Met-Thr) and identify which conformer is favoured.
Some of the most important organic compounds in biochemistry are the α-amino acids, represented by the general formula shown.Write structural formulas for the following α-amino acids.(a) Alanine (R = methyl)(b) Valine (R = isopropyl)(c) Leucine (R = isobutyl)(d) Isoleucine (R = sec-butyl)(e) Serine (R = XCH2, where X is the functional group that characterizes alcohols)(f) Cysteine (R = XCH2, where X is the functional group that characterizes thiols)(g) Aspartic acid (R = XCH2, where X is the functional group that characterizes carboxylic acids)
Designate the chiral centers of the following molecules and show which one of them is achiral?