3.1.5.1 Structure of DNA and RNA

DNA is polymer of

DNA nucleotides

Condensation reaction between two nucleotides forms

Phosphodiester bond

What enzyme catalyses formation of phosphodiester bond in DNA?

DNA polymerase

Each DNA nucleotide has

Deoxyribose sugar

Phosphate

Nitrogenous base

In which parts of nucleotides does condensation reaction take place?

Phosphate of one nucleotide pentose sugar of another nucleotide

4 DNA bases

Adenine

Thymine

Guanine

Cytosine

DNA molecule shape and other structure points

Double helix

Made up of 2 polynucleotide chains; held together by hydrogen bonds between specific complementary base pairings

Importance of many hydrogen bonds

Makes DNA stable

2 categories of nitrogenous bases

Pyrimidines (1 carbon ring & nitrogen atoms)

Purines (2 carbon rings & nitrogen atoms)

DNA strands are antiparallel- meaning?

DNA polymers = in opposite direction to each other

Importance of double helix and coiled structure

Gives DNA compact shape

Prevents genetic code being corrupted

Importance of covalent sugar phosphate backbone

Provide strength to structure of DNA

Importance of sequence of bases

Allows information to be stored

Importance of hydrogen bonds being easily broken

Allows the two strands to split easily for replication/transcription

Importance of DNA as long molecule

Store large amount of information

RNA nucleotide parts

Phosphate

nitrogenous base

Ribose sugar

Nitrogenous bases of RNA

Uracil

Adenine

Cytosine

Guanine

True or false, RNA is double stranded

False single strand

True or false RNA is a short polymer

True

Function of RNA

Used to transfer genetic information from nucleus to ribosomes

Gene

Sequence of DNA that codes for a polypeptide