Biology

• Nucleic Acids


  Biomolecules that store and transmit genetic information and has 2 forms
• Deoxyribonucleic acid (DNA)


  double helix macro molecule with antiparallel strands
• polymer


  molecules composed of many monomers; makes up macromolecules
• monomer of nucleic acids

  nucleotides (phosphate, 5 carbon sugar, nitrogenous base
• Nitrogenous bases in DNA

  adenine, guanine, cytosine, thymine
• nitrogenous bases in rna

  adenine, guanine, cytosine, uracil
• how monomers form polymers

  via bonds between sugar of one nucleotide and phosphate of another
• 5' end


  connects the bottom of phosphate and top of sugar
• 3' end


  connects top end or phosphate snd bottom of sugar. nucleotides can only be added to 3 end.
• shape of sugar


  saucepan shape, 5 being the handle
• DNA and RNA similarities

  - made of polymers composed of monomers

  -both nucleic acid

  -both contain adenine, guanine and cytosine
• DNA and RNA differences

  -DNA contains deoxyribose sugar whilst RNA contains ribose sugars

  - DNA has one less oxygen atom (no oxygen on 2nd carbon

  -DNA contains thymine whilst RNA contains uracil

  -DNA is double stranded whilst RNA is single stranded

  -DNA is found only in nucleus whilst RNA can be found in cytoplasm
• Ribonucleic acid (RNA)


  Single-stranded nucleic acid that contains ribose sugars and uracil, converts information in DNA into proteins. built by RNA Polymerisation
• RNA polymerization


  the process by which nucleotides are strung together to form a single-stranded RNA strand.
• DNA Structure


  Double-strande structure composed of nucleotides with sugar, phosphate, and nitrogenous
• RNA Structure


  Single-stranded structure composed of nucleotides with sugar, phosphate, and nitrogenous base
• Nucleotide


  Consists of a 5-carbon sugar, phosphate, and nitrogenous base
• Deoxyribose


  Sugar found in DNA
• Ribose


  Sugar found in RNA
• Thymine (T)


  Nitrogenous base found in DNA, pairing with adenine (A) through 2 hydrogen bonds
• Uracil (U)


  Nitrogenous base found in RNA, pairing with adenine (A) through 2 hydrogen bonds
• Double Helix


  The three-dimensional structure of DNA, consisting of two antiparallel strands
• Antiparallel


  The arrangement of the two DNA strands in opposite directions, with one strand running in the 5' to 3' direction and the other in the 3' to 5' direction
• Adenine


  Nitrogenous base that pairs with thymine (T) in DNA and with uracil (U) in RNA
• Guanine


  Nitrogenous base that pairs with cytosine (C) in DNA through 3 hydrogen bonds
• Cytosine


  Nitrogenous base that pairs with guanine (G) in DNA through 3 hydrogen bonds
• Messenger RNA (mRNA)


  RNA molecule formed through transcription, carrying genetic information from DNA to the ribosomes for protein synthesis
• Ribosomal RNA (rRNA)


  Main component of ribosomes (60%) and assists with protein synthesis within a cell
• Transfer RNA (tRNA)


  involved in the process of translation. clover lear shape. delivers and links amino acids
• Protein synthesis


  conversion of genetic code within DNA of a gene sequence into the functional unit (proteins)
• Transcription


  First step in Protein synthesis. Occurs in the Nucleus (Eukaryotes) DNA converts to pre- mRNA
• Transcription step 1


  Seperating the double helix strands of DNA. Helicase splits hydrogen bonds. RNA Polymerase brings nucleotides to templates
• Condensation reaction in RNA polymerization

  diphosphate molecule is produced
• Transcription step 2


  Copying the DNA code to create RNA. RNA Polymerase binds to the promoter and connects free RNA nucleotides until it reaches the terminator
• mRNA modifications


  Methyl cap is added to 5" end and poly-a tail is added to 3" end. Introns are removed so only exons remain
• Translation


  The process of converting information in RNA into a sequence of amino acids
• Proteins made by different ribosomes

  Free Ribosomes: Proteins used in the cell

  Rough ER Ribosomes: Outside the cell
• Translation steps


  1. mRNA buns to ribosome. 2. tRNA binds to mRNA through complementary bases 3. 3 bases on mRNA are called codons and the complementary bases on tRNA are called anticodons 4. When 2 tRNA molecules bind next to each other on the mRNA, their amino acids join forming a polypeptide chain
• How many tRNA can be attached to an mRNA

  2
• Stop Codon


  UAA, UAG, UGA