Cards (21)

    • DNA carries genetic code in living organisms
    • DNA is mainly found in the nucleus where it forms chromosomes. Also found in chloroplasts and mitochondria in eukaryotic cells.
    • RNA is main component of ribosome which plays important role for protein synthesis
    • Viruses are not consider as living organisms as they can not replicate themselves
    • RNA is maily found in the nuclus and cytoplasm
    • Both DNA and RNA are polymers which contain repeated units called nucleotides
    • Nucleotides form:
      • phosphate groupu
      • pentose sugar
      • base]
    • the base and phosphate groups are bonded by covalent bond
    • Nitrogenous base in DNA :
      • Adenine
      • Guanine
      • Cytosine
      • Thymine
    • The nitrogenous base can be categorised as either purine or pyrimidine
      • Adenine and Thymine are purine bases
      • Cytosine and Guanine are pyrimidine base
    • The phosphate group and next nucleotides are linked by condensation reaction
      →This means that molecules of water is released during formation of each covalent bonds
    • DNA is double strand while RNA is single strand
    • Draw the RNA nucleotide structure
    • Types of RNA
      • mRNA
      • tRNA
      • rRNA
    • mRNA
      formed in the nucleus and transported to the ribosome in the cytoplasm
    • tRNA
      responsible for transporting amino acid to ribosome during protein synthesis
    • rRNA
      forms part of ribosomes
    • RNA nucleotides are linked by condensation reaction
      → this forms a phosphodiester bond between pentose sugar and phosphate group
    • Each DNA polynucleotides have 3' end to 5' end
    • DNA molecules held together by hydrogen bonds
    • Adenine and Thymine, Guanine and Cytosine are complementary base pairng