The meaning of DNA is any of various nucleic acids that are usually the molecular basis of heredity, are constructed of a double helix held together by hydrogen bonds between purine and pyrimidine bases which project inward from two chains containing alt
Analysis of experimental examples of architectural motifs formed by the geometric combination of self-fitted DNA segments leads to general rules for DNA assembly. Like a directing piece for a supramolecular 'construction set', the double helix imposes a limited number of geometric solutions. These ...
Figure 6.Watson and Crickproposed the double helix model for DNA. (a) The sugar-phosphate backbones are on the outside of the double helix and purines and pyrimidines form the “rungs” of the DNA helix ladder. (b) The two DNA strands are antiparallel to each other. (c) The directi...
In a double helix DNA molecule normally found in all plants and animal, each successive base pair in the stack turns A)36 ͦ in a clockwise direction.B)36 ͦ in an anticlockwise direction.C)360 ͦ in a clockwise direction.D)360 ͦ in an anticlo
Different proteins have different functions on the double helix. Architectural Proteins that help to package DNA, bending and folding it, typically binding to 10–20 bp regions and often without a great deal of sequence dependence; examples include histones (eukaryotes) and HU, H-NS, and Fis (...
The requirement for binding on the same face of the double helix arises because the torsional rigidity of DNA prevents the untwisting or overtwisting necessary to bring the two proteins into appropriate spatial register when they are initially bound on opposite faces of the duplex. The presence of...
Examples of the A- and B-forms of DNA have now been studied extensively, first by fibre diffraction (Arnott et al., 1976) and later by single-crystal X-ray crystallography (Dickerson, 1991). Both are righthanded forms of a DNA double helix, with the B-form corresponding closely to the...
like the mythical serpents. DNA is also connected with water. All cells contain salt water which helps the DNA to twist into the double helix shape. It does this to protect itself because the four bases (A, G, C, and T) are insoluble in water so they twist up inside the cell to st...
due to the chemical structures of the bases—the pair is like a rung or step on a spiral staircase. This means that the two strands of the double helix can be separated, and new strands can be formed that copy the information exactly. The new strand carries the same information as the ...
Describe the complementary base pairing between the two individual strands of DNA that forms the overall double-helical structure. If one strand of a DNA double helix has the sequence ATCGATCGAT, what is the sequence of the other DNA strand?