A 1.2 Nucleic acids

• DNA is the genetic material of all living organisms.
• Some viruses use RNA as their genetic material but viruses are not considered to be living
• RNA is a polymer formed by condensation of nucleotide monomers.
• DNA is a double helix made of two antiparallel strands of nucleotides with two strands linked by hydrogen bonding between complementary base pairs.
• Sugar–phosphate bonding makes a continuous chain of covalently bonded atoms in each strand of DNA and RNA. This is the sugar-phosphate “backbone”.
• ribose


  -

  
• nucleotide


  -

  
• strand


  -

  
• backbone 


  -

  
• antiparallel strand 


  -

  
• dna nucleotide


  -

  
• rna nucleotide


  -

  
• deoxyribose 


  -

  
• tRNA


  -

  
• mRNA


  -

  
• rRNA


  -

  
• ATP

  -

  
• DNA strand


  -

  
• Rna strand 


  -

  
• polynucleotide chain

  -

  
• Bases in each nucleic acid form the basis of a code
• nucleic acids

  • genetic material of the cell is composed of recurring monomeric units called nucleotides (they express genetic information)
  • organic molecules
  • store the coded instructions for the expression of proteins, which determine the characteristics of a cell.
  • These instructions are passed between generations – making the nucleic acids responsible for inheritance within a species.
• Nucleotide properties


  Covalently bonded together, forming a longchain sugar-phosphate bonding, which forms astrong sugar-phosphate backbone which holds the molecule together
• describe strand formation


  Nucleotide monomers are linked together into asingle strand via condensation reactions (waterproduced as a by-product)
• what bonds are present between the phosphateand sugar

  covalent
• DNA is diverse and universal….

  • The divergence of DNA molecule lengths and base sequences enables a huge range of genetic diversity.
  • the genetic code appears as triplets (groups of3)
  • there are 64 combinations
  • any given triplet codes for the same amino acid, regardless of what organism it is,
• • There is a huge diversity of possible DNA base sequences and DNA has a limitless capacity for storing information.
  • diversity by any length of DNA molecule and any base sequence is possible.
  • DNA has an enormous capacity for storing data with great economy.
• Conservation of the genetic code across all life forms is evidence of universal common ancestry.
• Each nucleotide is comprised of three components

  • • A pentose sugar (organised into a 5-carbon cyclic structure)
  • A nitrogenous base (attached to the sugar at the 1’-carbon)
  • A phosphate group (attached to the sugar at the 5’-carbon)
• sugar phosphate backbone

  • Nucleotides are joined together by condensation reactions to form long polynucleotide chains.
  • Nucleotides are connected between the 5’-phosphate and the 3'-position of the sugar.
  • The sugars and phosphates form a backbone, while the bases extend outward. The order of the base sequence forms the coded instruction.
• what bonds are present between the 2complementary bases


  hydrogen
• where is oxygen on the nucleotide structure


  the point of the pentose sugar
• what carbon direction is a dna strand in

  3’-5’(clockwise)
• How many carbon atoms are a sugar?


  5
• what position is the phosphate of a nucleotideconnected to?

  at the 3’ hydroxyl position
• similarities between DNA and RNA

  • Polymers made up of nucleotide
  • monomers
  • Sugar, phosphate, nitrogenous bases make up a nucleotide
  • Adenine, Guanine and Cytosine
  • Sugar-phosphate backbone
  • joined by covalent bonds
• DNA functions as the master template of the genetic instructions and remains in the nucleus of eukaryotic cells (or in the nucleoid region of prokaryotic cells).
• RNA functions as a transient copy of the template instructions and is transported to the ribosomes to synthesise proteins.
• examples of nucleic acids

  Dna

  RNA
• differences between DNA and RNA

  • Thymine vs Uracil
  • Deoxyribose vs Ribose
  • Double vs single stranded
  • Double helix vs various shapes
  • Permanent genetic code vs
  • impermanent (except in viruses)