SESSION 14

Nucleotide

A building block of DNA and RNA, consisting of a phosphate group, a sugar, and a nitrogenous base.

Deoxyribose

The sugar present in DNA nucleotides.

Ribose

The sugar present in RNA nucleotides.

Phosphodiester bond

The bond that connects nucleotides in a nucleic acid, linking the 3'-OH of one nucleotide to the 5'-phosphate of another.

Sugar-phosphate backbone

The structural framework of DNA and RNA formed by alternating sugar and phosphate groups.

Base pairings in DNA

Adenine pairs with Thymine (A=T) and Guanine pairs with Cytosine (G≡C).

Base pairings in RNA

Adenine pairs with Uracil (A=U) and Guanine pairs with Cytosine (G≡C).

Double helix

The structure formed by two strands of DNA wound around each other, stabilized by hydrogen bonds between complementary bases.

Primary structure of DNA

The sequence of nucleotides in a DNA molecule.

Secondary structure of DNA

The double helical structure formed by hydrogen bonding between base pairs in DNA.

Stability of DNA

DNA is double-stranded and stable due to its structure and base pairing.

Stability of RNA

RNA is single-stranded and less stable than DNA, making it more prone to degradation.

Uracil

A nitrogenous base found in RNA that replaces thymine found in DNA.

Hydrogen bonds in proteins

Weak attractions that form between non-adjacent amino acids, creating secondary structures such as α-helices and β-sheets.

Primary structure of proteins

The sequence of amino acids in a protein.

Condensation reaction

A chemical reaction in which two molecules join together, releasing a molecule of water, as seen in the formation of phosphodiester bonds.