AP Bio Final Project

Unknown

DNA: deoxyribose (H instead of OH)

  • Made of a phosphate, pentose sugar, and nitrogenous base

    • Individually, nucleotides, together, nucleic acids

  • Bind anti-parallel (opposite to each other)

    • Adenine-Thymine: Double H-Bond

    • Guanine-Cytosine: Triple H-Bond

  • 5’ (phosphate) Side on the left, 3’ Side on the right

  • Purines (Pure As Gold): Adenine and Guanine (2x Ring)

  • Pyrimidine: Thymine, Cytosine, Uracil (1x Ring)


RNA: ribose

  • Substitute Uracil for Thymine

    • mRNA: makes proteins from DNA

    • tRNA: transfers amino acids to ribosome

    • rRNA: helps ribosome make stuff


DNA Replication

  • Helicase unwinds DNA strand, then splits it down the middle like a wedge

  • RNA primer preps the first two base pairs

  • Polymerase only works in the 5’ to 3’ direction (leading strand)

  • Okazaki fragments made and closed by ligase form the lagging strand

  • Topoisomerase straightens the end


DNA Coding

  • DNA coding > mRNA > proteins

  • Transcription

    • Polymerase makes an mRNA strand that leaves the nucleus

      • Template/antisense strand: what is copied

      • Coding strand: what’s coded into mRNA with U instead of T

  • Splisosome cuts out introns and leaves exons

    • Alternative RNA splicing allows different proteins to be coded

      • Introns/exons differ between proteins

  • Translation

    • Ribosome binds to mRNA

    • A-Site: reads next codon and codes (codon is 3 letters, i.e. AUG)

    • P-Site: makes amino acid chain

    • E-Site: exit site where tRNA drags acid along

    • Start and stop codons do starting and stopping duh


Other Stuff

  • Histones

    • DNA is coiled around histones

      • 8 histones = nucleosome

    • How coiled it is = how expressed it is

    • More coiled = less expressed

      • Methylation coils it more

      • Acetylation activates it more

  • Operons

    • Promoter: where polymerase binds to express structural genes

    • Operator: stoplight for polymerase

    • Repressor: when active, it binds to the operator, preventing polymerase expression. When inactive, it doesn’t bind, allowing polymerase to express

  • Lac Operon (for lactose)

    • The repressor is active when there is no lactose

    • When lactose is produced, it produces allolactose which takes out the repressor


Mutations

  • Point Mutation: letters are randomly misplaced

    • Single Nucleotide Polymorphisms (SNPs) are a form of point mutation, each SNP being in at least 1% of the population

    • Insertion: letters are added?

    • Deletion: letters are removed

    • Substitution: letters are replaced

  • Frame Shift: codons or acids are deleted

  • Aneuploidy: wrong number of chromosomes


Variation

  • Humans do natural selection; if the gene is rly shit you’ll die; if it’s good, you’ll live and have sex

  • Bacteria

    • Transduction: virus transfers genes from bacteria to bacteria

    • Transformation: grabs genetic info from environment

    • Conjugation: bacteria basically just kiss each other and exchange stuff


Biotech

  • Restriction enzymes can cut bacteria and an excess gene to put the excess gene into a sticky part

  • PCR

    • RNA primers, DNA, and polymerase are all together

      • Taq Polymerase: Isolated from a bacterium found in hot springs and deep-sea vents. Used in PCR because it can withstand heat without denaturing itself. 

    • Heat it up to unwind it

    • Primers latch on, polymerase elongates it and now you have more strands

  • Gel Electrophoresis

    • Charge opposite ends of an agar gel and depending on the charge of the DNA strand, see how it travels across the gel

      • Smaller strands travel farther

  • Recombinant DNA: taking DNA from 2+ sources and putting it into 1

    • Produce protein products (like a bacteria that makes insulin)

    • Replace non-functional genes with functional ones


  • Plasmids

    • Commonly used to introduce foreign DNA into cells for gene cloning, gene expression, and protein production

    • Small, circular, double stranded