chapter twenty two nucleic acids. copyright © houghton mifflin company. all rights reserved.22 | 2...
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Chapter Chapter Twenty TwoTwenty TwoNucleic Acids
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→ CO 22.1Human egg and sperm.
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Dr. Nikos / James Burns / Phototake
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→ Fig. 22.1Molecule of Adenine, a nitrogen-containing heterocyclic base present in both RNA and DNA.
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← Fig. 22.2 Two purine bases and three pyrimidine bases are found in the nucleotides present in nucleic acids.
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Table 22.1
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CAG 22.1
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Fig. 22.3 The general structure of a nucleic acid in terms of nucleotide subunits.
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← Fig. 22.4 (a) The generalized structure of a nucleic acid. (b) The specific backbone structure for a deoxyribonucleic acid (DNA). (c) The specific backbone structure for a ribonucleic acid (RNA).
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→ Fig. 22.5 A four-nucleotide-long segment of DNA.
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Fig. 22.6 A comparison of the primary structures of nucleic acids and proteins.
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→ Fig. 22.7 A schematic drawing of the DNA double helix that emphasizes the hydrogen bonding between bases on the two chains.
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← Fig. 22.8
Hydrogen bonding possibilities
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Fig. 22.9 DNA replication
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Fig. 22.10 One strand of DNA grows continuously in the direction of the unwinding, and the other grows in the opposite direction.
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→ Fig. 22.11 DNA replication usually occurs at multiple sites within a molecule, and the replication is bidirectional from these sites.
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← Fig. 22.12 Identical twins share identical physical characteristics because they received identical DNA from their parents.
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© Erica Stone / Peter Arnold, Inc.
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CAG 22.2
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Fig. 22.13 A hairpin loop is produced when a single-stranded RNA doubles back on itself and complementary base pairing occurs.
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Fig. 22.14
An overview of types of RNA.
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→ Fig. 22.15 The transcription of DNA to form RNA involves an unwinding of a portion of the DNA double helix.
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Fig. 22.16 Heterogenous nuclear RNA contains both exons and introns.
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Fig. 22.17 An hnRNA molecule containing four exons.
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Table 22.2
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← Fig. 22.18
A tRNA molecule
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→ Fig. 22.19 An aminoacyl-tRNA synthetase has an active site for tRNA and a binding site for the particular amino acid that is to be attached to that tRNA.
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← Fig. 22.20 The interaction between anticodon an codon.
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→ Fig. 22.21 Ribosomes have structures that contain two subunits.
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Fig. 22.22Initiation of protein synthesis begins with the formation of an initiation complex.
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→ Fig. 22.23 The process of translation that occurs during protein synthesis.
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CC 22.1
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← Fig. 22.24 Several ribosomes can simultaneously proceed along a single strand of mRNA. Such a complex of mRNA and ribosomes is called a polysome.
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CAG 22.3
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→ Fig. 22.25 Image of an influenza virus.
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NIBSC / SPL / Photo Researchers
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← Fig. 22.26 Recombinant DNA is made by inserting a gene obtained from DNA of one organism into the DNA from another kind of organism.
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→ Fig. 22.27 Cleavage patterns resulting from the use of a restriction enzyme that cleaves DNA between G and A bases.
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← Fig. 22.28 The “sticky ends” of the cut plasmid and the gene are complementary and combine to form recombinant DNA.
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→ Fig. 22.29 The basic steps of the polymerase chain reaction process.
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← Fig. 22.30 Selected steps in the DNA sequencing procedure for the 10-base DNA segment 5’ AGCAGCTGGT 3’.
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