11. What is the anatomical structure (shape) of DNA? 12. Is DNA single or double
ID: 74362 • Letter: 1
Question
11. What is the anatomical structure (shape) of DNA? 12. Is DNA single or double stranded? 13. What bond holds the two strands in DNA together? 14. In a eukaryotic cell, where does the process of ‘DNA replication’ take place? 15. If DNA is a ladder, what part of DNA would be considered the rungs? Which part of DNA would be considered the upright portions of the ladder? 16. If the one strand is 5’ –ATTCAGGACTCC- 3’, what is the nucleotide sequence of the complementary strand? 17. How many DNA triplets are there in the DNA from question #16? How many amino acids would be coded for (from #16)?
Explanation / Answer
11. The Deoxyribonucleic acid or DNA is a double helical structure in which the strands overlap each other in antiparallel way forming helix.
There are nitrogenous bases which are hydrogen bonded tp the complementary bases. like purine bae pairs to purine and pyrimidine base pairs to pyrimidine.
Nucleotide is the basic unit of DNA composed of one deoxyribose sugar, nitrogenous bases and phosphate bond.
12.DNA is usually double stranded but in some viruses DNA can also be single stranded.
13.Hydrogen bonds holds the two strand in DNA together.
There are two hydrogen bonds present between purine of the strands and three hydrogen bonds present between pyrimidines of the two strands.
14.DNA replication takes place in the S phase of cell cycle inside the nucleus.
15. The nitrogenous bases make up the 'rungs' of the ladder, and are attached to the backbone where the deoxyribose (sugar) molecules are located.
The uprights of the ladder are formed by phospho-ribose residues. Each nucleotide has a 5 carbon sugar called ribose which forms phosphodiester bonds along the length that keeps the single strands of DNA together.
16. If one strand is 5’ –ATTCAGGACTCC- 3’, then the complementary strand will be:
3'-TAAGTCCTGAGG-5'
17.There are 4 triplets ATT, CAG, GAC, TCC
therefore four amino acid will formed from this sequence.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.