Antiparallel strands of a DNA molecule means thata)the phosphate group...
Antiparallel strands of a DNA molecule means that the phosphate groups at the start of two DNA strands are in opposite position (pole). DNA is composed of two polynucleotide strands, which form what looks like a ladder. The two polynucleotide strands run 'antiparallel' to each other, with nitrogenous bases projecting inwards. The term 'antiparallel' means that the strands run in opposite directions, parallel to one another. The antiparallel strands twist in a complete DNA structure, forming a double helix. It runs 3'-5' and 5'-3' linkage. The 5' and 3' mean "five prime" and "three prime", which indicate the carbon numbers in the DNA's sugar backbone. The 5' carbon has a phosphate group attached to it and the 3' carbon a hydroxyl (-OH) group. This asymmetry gives a DNA strand a "direction".,,..
Antiparallel strands of a DNA molecule means thata)the phosphate group...
Antiparallel Strands of a DNA Molecule
The concept of antiparallel strands in a DNA molecule refers to the orientation of the two strands relative to each other. This has significant implications for the structure and function of DNA.
Explanation:
- Opposite Position of Phosphate Groups: In a DNA molecule, the two strands run in opposite directions. One strand runs in the 5' to 3' direction, while the other runs in the 3' to 5' direction. This means that the phosphate groups at the start of the two DNA strands are in opposite positions or poles.
- Complementary Base Pairing: The antiparallel arrangement of DNA strands allows for complementary base pairing. Adenine on one strand always pairs with thymine on the other, and guanine always pairs with cytosine. This base pairing is essential for the replication and transmission of genetic information.
- Structural Stability: The antiparallel arrangement contributes to the structural stability of the DNA molecule. The hydrogen bonds between the complementary base pairs help hold the two strands together, forming the characteristic double helix structure.
- Replication Process: During DNA replication, the antiparallel orientation of the strands allows for the semi-conservative replication process. Each original DNA strand serves as a template for the synthesis of a new complementary strand, resulting in two identical daughter DNA molecules.
- Overall Importance: The antiparallel arrangement of DNA strands is crucial for the storage, replication, and transmission of genetic information. This structural feature ensures the faithful inheritance of genetic material from one generation to the next.
In conclusion, the antiparallel orientation of DNA strands plays a fundamental role in the structure and function of DNA, contributing to its stability, replication, and genetic fidelity.
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