nucleotides and nucleic acids

• structure of a nucelotide

  phosphate, sugar, base
• difference between nucleotide in rna and dna: ribose vs deoxyribose rugar
• phosphorylated nucleotide


  more than one phosphate group
• phosphate groups in ADP vs ATP


  2,3
• pyramidines


  CUT
• purines


  AG
• difference between pyramidines and purines: 1 ring vs 2 rings
• polymer: a polynucleotide which forms through condensation between phosphate groups
• what bond forms in a polynucleotide: phosphodiester (1 phospho, 2 ester)
• what is energy needed for: anabolic reactions (small-big)

  moving substances (AT)

  muscle contraction

  conduction of nerve impuslses
• what is ATP


  phosphorylated nucelotide which carries energy
• structure of DNA


  double helix, antiparallel strands
• what carbons join in DNA: 5 carbon to 3 carbon on sugars
• phosphodiester bonds in DNA: phosphate to C5 - C3 to phosphate - C5
• difference between ester and phosphodiester: ester is C-O, phosphodiester is the entire structure
• hydrogen bonds in DNA: 2 strands held together by H bonds
• AT hydrogen bonds


  2
• CG hydrogen bonds


  3
• antiparallel meaning


  the direction c3 and 5 are facing
• what is the 5 prime end: where phosphate group attaches to c5
• DNA purification by precipitation: washing up liquid, water and strawberry in beaker

  -heat to 60 in water bath

  -cool mixture in ice bath and stir

  -mash

  -filter into beaker

  -+ protease

  -+ice cold ethanol
• purpose of detergent and heat in DNA purification by precipitation: disrupt phospholipid bilayer, releasing DNA

  -denature digestive enzymes
• purpose of cooling mixture in DNA purification by precipitation: prevents DNA from breaking down
• purpose of mashing in DNA purification by precipitation: breaks down walls and membranes (not too much)
• purpose of filtering in DNA purification by precipitation: removes debris, leaves DNA and proteins
• purpose of protease in DNA purification by precipitation: leaves just DNA
• purpose of ice cold ethanol in DNA purification by precipitation: nucleic acids and insoluble in ethanol= ppt
• purpose of semi-conservative replication: -new cells inherit all new genes

  -replacement and growth
• rough outline of DNA replication: replicates before mitosis in s phase

  -helicase untwists

  -templates formed
• where is DNA in a eukaryotic cell: -majority in nucleus

  -around histone (chromosome)

  -loop of DNA not around. histone on the mitochondria and chloroplast
• how is DNA organised in a prokaryotic cell: -in a loop in cytoplasm

  -NOT around histones
• semi conservative DNA replication % heavy in gen 0 1 and 2: 100, 50, 25
• DNA replication up until unzipping


  -gyrase unwinds

  -helicase unzips
• DNA replication from unzipping up until lagging strand: -free phosphorylated nucelotides bind to exposed bases

  -DNA polymerase catalyses addition in 5'-3'

  -leading strand synthesised continuously (5'-3')

  -lagging strand synthesised in fragments (3'-5')
• DNA replication from lagging strand to end: hydrolysis of activated nucleotides - releases energy pf extra phosphate groups to make phosphodiester bonds with sugar residue
• types of possible mutations (simple): -extra base

  -missing base

  -wrong order
• RNA vs DNA: -ribose vs deoxyribose

  -u vs t

  -single vs double stranded

  -shorter vs longer
• nature of the genetic code: 3 bases = 1 amino acid

  -20 amino acids

  -universal
• what does it mean that the genetic code is degenerate: theoretically 64 different combinations, but only 20 amino acids. many code for the same
• what is a gene: sequence of nucleotides that forms a section of DNA