Define,phosphate groups,suger <span title="group,nitrogenbases,nusletide,">group,nitrogenbases,nusle...</span> bond,and polynucleotide?

Question

q2)using diagrams,illistrate some examples of nondisjunction.

q3)describe the pattren of pairing of nucletides.

please help me out

Answer 1

Okay I&#039;ll try to help as best as I can..

A nucleotide has 3 components: a 5-carbon sugar, a nitrogenous base and a phosphoric acid (the phosphate group).

The sugar component in a nucleotide has 5 carbon atoms. The 2 types of nucleic acids (DNA and RNA) differ in the type of sugar they contain. The sugar ribose is present in RNA, the sugar deoxyribose is present in DNA. Deoxyribose differs from ribose in that the hydroxyl group (-OH) at carbon 2 is replaced by a hydrogen atom.

The phosphate group gives the nucleotide its acidic character, its formula is H3PO4.

Each nucleic acid contains 4 different bases (Adenine, Guanine, Cytosine, Thymine), which can be categorized into purines and pyrimidines. Purines have 2 rings whereas pyrimidines have 1 ring in their structure.

In DNA: purines are Adenine and Guanine, pyrimidines are Cytosine and Thymine.

In RNA: purines are Adenine and Guanine, pyrimidines are Cytosine and Uracil.

These 3 components (sugar + phosphoric acid + nitrogenous base) link up to form a nucleotide via the process of condensation. The nitrogenous base attaches to carbon 1 of the sugar group, and the phosphoric acid attaches to carbon 5 of the sugar group. Two water molecules are removed in the process and hence its condensation.

Combining nucleotides would result in a polynucleotide. The covalent bond linking adjacent nucleotides is called a phosphodiester bond. These link up to form 1 strand of DNA or RNA. This strand then &quot;pairs up&quot; with another strand via complementary base-pairing.

Adenine to Thymine, Cytosine to Guanine.

It&#039;s quite tough to explain it all here.. Maybe you could check out your notes or textbook. It is much more useful to have diagrams. Hope I&#039;ve helped though!