Concept explainers
RECALL How do D-amino acids differ from L-amino acids? What biological roles are played by peptides that contain D-amino acids?
Interpretation:
The difference between
Concept information:
Amino acids are the building blocks of proteins.
These are more than 900 amino acids, but among them only 20 amino acids are found in proteins.
The structure of amino acids contains a carboxyl group and an amino group, both bonded to the
Answer to Problem 1RE
The stereochemistry of
Explanation of Solution
All amino acids except glycine have two forms. These two forms of the same amino acid are referred to as stereoisomers. Amino acids having an active chiral carbon (carbon bonded with four different groups) show stereoisomerism. These stereoisomers are referred to as
The
The difference between
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Chapter 3 Solutions
Biochemistry
- RECALL What are caspases?arrow_forwardRECALL Are amino acids other than the usual 20 amino acids found in proteins? If so, how are such amino acids incorporated into proteins? Give an example of such an amino acid and a protein in which it occurs.arrow_forwardREFLECT AND APPLY Glycine is a highly conserved amino acid residue in proteins (i.e., it is found in the same position in the primary structure of related proteins). Suggest a reason why this might occur.arrow_forward
- REFLECT AND APPLY Suggest an explanation for the observation that when proteins are chemically modified so that specific side chains have a different chemical nature, these proteins cannot be denatured reversibly.arrow_forwardRECALL Sketch resonance structures for the peptide group.arrow_forwardREFLECT AND APPLY List two classes of compounds derived from arachidonic acid. Suggest some reasons for the amount of biomedical research devoted to these compounds.arrow_forward
- REFLECT AND APPLY The fidelity of protein synthesis is assured twice during protein synthesis. How and when?arrow_forwardREFLECT AND APPLY The amino acid hydroxyproline is found in collagen. There is no codon for hydroxyproline. Explain the occurrence of this amino acid in a common protein.arrow_forwardREFLECT AND APPLY Immature rats are fed all the essential amino acids but one. Six hours later they are fed the missing amino acid. The rats fail to grow. Explain this observation.arrow_forward
- BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage Learning