BIOL 150

• Scientific method


  1. Observation/question

  2. Research

  3. Hypothesis

  4. Experiment

  5. Analysis

  6. Conclusion
• Null hypothesis


  A hypothesis that is tested in an experiment
• Experiment


  • Write a null hypothesis
  • Determine independent variable and dependent variable
  • Identify control
  • Make predictions
• When graphing data


  The independent variable goes on the x-axis and the dependent variable goes on the y-axis
• Types of graphs


  • Line graph (for continuous data)
  • Pie chart (for percent of a whole data)
  • Bar graph or cat and whiskers diagram (for categorical data)
• Chromosomes


  Nucleic acids and proteins that store genetic information in living cells
• Eukaryotic cells


  • Chromosomes in nucleus
• Prokaryotic cells


  • Chromosomes in cytoplasm (no nucleus)
• Genes


  A sequence of genetic material that determines an organism's traits
• Genetic material


  Nucleic acids that make up genes
• DNA


  A nucleic acid polymer made up of monomers
• DNA and RNA


  Sugars vary between them
• Pyrimidine


  A single ring nitrogenous base (C, U, T)
• Purine


  A double ring nitrogenous base (G, A)
• Primary structure of DNA


  • A directional sugar-phosphate backbone
  • Nucleotides are added to the 3' end which is a free hydroxyl group
• Secondary structure of DNA

  • An antiparallel double helix
• Tertiary structure of DNA


  • In eukaryotes, DNA wraps around histone proteins forming chromosomes
• DNA replication


  1. Uses genetic code in DNA to synthesize new DNA molecules

  2. Semi conservative because parental strands separate and each is used as a template for a new daughter strand

  3. Synthesized from the 5' end to the 3' end
• DNA replication


  1. bonds between paired nitrogenous bases must be split to create new DNA molecules
• Genetics


  The linking of genes to chromosomes and the production of gametes
• Central dogma


  Summarizes the flow of information from DNA to proteins
• Transcription


  DNA to mRNA in the nucleus
• Translation


  mRNA to proteins in the cytoplasm
• mRNA


  • Single stranded
• Transcription


  Uses the template DNA strand to produce mRNA which carries genetic information out of the cell's nucleus
• Translation


  Uses mRNA to synthesize proteins, using mRNA as genetic code to produce protein
• Proteins/polypeptides


  • Function as cell machinery (enzymes)
• Protein structure

  The order of amino acids determines shape of protein which determines function
• Codon


  A triplet of mRNA bases which specifies which amino acid is added to the polypeptide chain
• Gene

  A section of DNA which codes for a protein
• Genes vary in size
• A pairs with T and G pairs with C
• In double stranded DNA, the percent of A equals the percent of T and the percent of G equals the percent of C
• H-bonds hold the two stands of DNA together. The pattern of H-bonds determines base pairing rules
• DNA twists to a helix because interactions with aqueous cellular environment because the bases are hydrophobic
• Genetic code


  • Redundant - most amino acids are coded for by more than one codon
  • Unambiguous - a given codon never codes for more than one amino acid
  • Non overlapping - once the ribosome locks onto the start codon, the reading frame is established and the ribosome reads each separate codon
  • (Nearly) universal - all codons specify the same amino acids in all organisms
  • Conservative - when several codons specify the same amino acid, the first two bases in those codons are usually identical
• Chromosome


  Made up of a single long DNA double helix wrapped around histone proteins
• Chromatin


  A complex of DNA and proteins that composes chromosomes
• Locus


  The physical location of the gene on the chromosome
• Ploidy


  The number of sets of unique chromosomes in the cell