4. Nucleic acids and ATP

What is the stucture of a phospholipid?

Phosphate group

pentose Sugar

Nitrogen containing base

What is the pentose sugar in DNA?

Deoxyribose

What is the pentose sugar in RNA?

Ribose

What is the role of DNA in living cells?

Base sequence of genes codes for fRNA and amino acid sequences. Genetic information determined inherited charachteristics

What is the role of mRNA in living cells?

Complimentary sequence to 1 gene from DNA with introns spliced out. Can be translated into polypeptides by ribosomes

What is the role of rRNA in living cells?

Components of ribosomes

What is the role of tRNA in living cells?

Supplies complimentary amino acids to mRNA codons during translation

How do polynucleotides form?

Condensation reactions between nucleotides form strong phosphodiester bonds

What is the structure of DNA?

Double helix of 2 polynucleotide strands

H bondsbetween complimentary base pairs on opposite strands

What bases are purine?

A & G (2 ring)

What bases are pyrimidine?

T & C & U (1 ring)

What is the structure of mRNA?

• Long ribose polynucleotide

• Contains uracil

• Single stranded

• Codon sequene is complimentary to exons of 1 gene from 1 DNA strand

What is the structure of tRNA?

• single strand of about 80 nucleotdes

• folded into clover shape

• Anticodon at one end

Why is DNa replication described as semiconservative?

• STrands from original DNA mlecule act as a template

• New DNA molecule contains one old and one new strand

What is the structure of adenosine triphosphate?

Adenine base

ribose sugar

three phophates

What is the role of ATP?

To release energy for use in metabolice reacions

How is ATP resynthesised in cells?

ATP synthase catalyses condensation reactions between ADP & Pi

Why is ATP a suitable energy currency in cells?

• Hgh energy bond

• Small amount of energy released at a time (reduces waste)

• Single step

• Easily resynthesised