Please enable JavaScript.

Coggle requires JavaScript to display documents.

Chapter 16 & 17 (DNA replication (DNA proteins (Primase (synthesizes…

- - - - Replication Fork
      - The end of the replication bubble where DNA is elongated
      - Single strand binding proteins
        
        Stabilize the Strand
      - Topoisomerase
        
        Breaks and rejoins the strands
      - Helicases
        
        enzymes that untwist the Helix at the replication fork sites
  - - - Synthesized in fragments joined by DNA ligase
  - - - synthesizes RNA primer
    - - adds nucleotides
    - - stabilizes strand
    - - removes RNA nucleotides from primer
    - - unwinds double helix at replication fork
    - - joins the okazaki fragments
  - - - Enzymes correct base pair pairings
    - - Nuclease cuts out and replaces bad stretches of DNA
    - - special nucleotide sequence
        
        Protects DNA from erosion
- - - - ribosomoal rna rRNA help couple
        
        Ribosomes have 3 binding sites for tRNA
        
        E
        
        exit site where tRNA's are discharged
        
        A
        
        carries next amino acid to chain
        
        P
        
        Holds the polypeptide
  - - - aminoacyl-tRNA synthetase
- - - - where RNA pol attatches
    - - signals end of transcription
  - - - RNA pol untwists 10-20 bases at a time
      - 40 nucloetides per second
      - multiple polymerases can work at a time
    - - Promoters signal the start point
        
        TATA box promoter is crucial
      - Transcription Factors help the binding of RNA pol
      - Both of these are the Transcription Initiation Complex
    - - Termination varies for eukaryotes and bacteria
        
        eukaryotes, after polyadenylation is transcribes it goes 10-35 nucleotides past
        
        Bacteria, the pol stops transcription at the end of stop code and mRNA can be translated
    - - Happens only in Eukaryotes
      - modifies mRNA before it is released into the cytoplasm
      - both primary transcript ends are altered
      - 5' end recieves a 5 cap and 3' end recieves a poly- a tail
      - Genes have non coding regions called Introns
        
        Exons are important regions that are expressed
        
        RNA splicing cuts out the introns and combines exons to create a more complete strand
        
        Spliceosomes
        
        proteins and rna's that do RNA splicing
        
        Ribozymes
        
        can splice rna and function as enzynes
  - - - changes in one nucleotide
    - - Replaces a nucleotide and its pair with another set
    - - no affect on amino acid because of repetition in code
    - - code for the wrong amino acid
    - - change amino codon to stop codon = nonfunctional protein
    - - additions or losses of nucleotide pairs
      - can alter the reading frame
      - very bad for genes
- - - - Purine and Pyrimidine pairings on helix
    - - A & T paired G & C
    - - Pyrimidine
    - - Purine
- - - - 3 nucleotide code
      - 3 nucleotides of mRNA
      - Translated into amino acid
    - - mRNA base triplets
      - Read 5' to 3'
        
        Reading Frame is important
      - Codon pattern specifies a certain amino acid
      - 64 codons
        
        60 amino acids codes 1 start 3 stops