DNA and RNA

when was the double-stranded DNA structure determined?

in 1953

who were the two people involved in determining the structure of DNA?

James Watson and Francis Crick

how did Rosalind Franklin’s findings help?

her X-ray diffraction studies suggested that DNA was a helical structure

What did Erwin Chargraff show about DNA?

that there was a 1:1 ratio between pyrimidine and purine bases

how do nucleotides make up the structure of DNA?

nucleotides from strong covalent bonds with each other when the phosphate group of one bonds to the sugar group or another, forming a POLYNUCLEOTIDE

how many polynucleotide strands does DNA consist of?

2 polynucleotide strands

what is the backbone of the DNA’s structure?

a sugar-phosphate arrangement with bases projecting towards the inside of the double helix

what are the bonds between the base pairs?

weak hydrogen bonds, holding the polynucleotide strands together

what are the 3 types of RNA?

• rRNA ribosomal

• tRNA transfer

• mRNA messenger

what are tRNA transfers used for?

used in the translation process to transport specific amino acids

how is mRNA messenger formed?

formed by transcription

what is the difference in the nucleotides in RNA vs DNA?

• they contain ribose not deoxyribose

• Uracil is used instead of Thymine

• Molecule is single not double stranded

how is DNA packaged in eukaryotic cells?

in chromosomes in the nucleus

how many metres of DNA must fit in the nucleus?

2 metres

what proteins make up chromatin which make up chromosomes?

histone proteins

what is the average length of DNA in a human chromosome?

4.8cm long

what are some similarities between DNA and RNA?

• both contain a phosphate group, pentose sugar and nitrogen base

• both form through 2 condensation reactions

• both contain phosphodiester bonds