Notes from lab lectures

• List the four steps of the scientific method:

  1. Make observations and identify a problem
  2. Formulate a null hypothesis
  3. Test the hypothesis, gather and analyze data to test
  4. Reject or fail to reject the null hypothesis
• List the four things you need to formulate a hypothesis:

  1. The hypothesis needs to be specific to your question
  2. The hypothesis needs to be testable/falsifiable
  3. The hypothesis needs to propose mechanistic or natural causes
  4. Provisional explanation
• What is a theory?

  A general explanatory framework based on well-tested hypotheses; fact reference to theory
• DNA is a molecule of inheritance
• Two strands of simple units of DNA are held together by hydrogen bonds between complementary bases. These are called nucleotides.
• Sugar is the backbone for phosphate in DNA.
• The three things that make up DNA are the base, the sugar and the phosphate.
• 1 nucleotide = 1 sugar phosphate + 1 base
• DNA is double stranded. Think that D stands for "double".
• RNA is single stranded. Think single Ronnie.
• Weak hydrogen bonds connect strands of DNA.
• When "unzipping" DNA, an enzyme comes through and breaks the hydrogen bond that connects the strand, breaking it apart so that it can be replicated.
• DNA -> mRNA -> tRNA -> Amino Acid Chain (polypeptide chain)
• DNA replication happens in the nucleus.
• Transcription happens in the nucleus.
• Translation happens in the cytoplasm outside of the nucleus.
• Four steps of Transcription:

  1. Two DNA strands separate partially
  2. Fee floating mRNA (messenger) nucleotides are attracted
  3. mRNA is complement of DNA template strand with uracil instead of thymine.
  4. Transcription ends at terminator region
• In translation:

  1. mRNA binds to ribosome
  2. tRNA (transfer RNA) brings particular amino acid specified by mRNA codon
  3. tRNA binds to first codon while second tRNA amino acid complex arrives at ribosome
  4. Ribosome moves down mRNA, allowing third amino acid to be brought into position.
  5. First two amino acids are joined - polypeptide chain.
• 3 ribosomes = codon
• Start and stop codons tell us where the protein starts and stops. They are at the beginning and end of each chain and tells our sequence to break off that protein and move onto the next one. This is how we get a new cell or DNA molecule.
• Genes are sections of DNA that code.
• Think of transcript like a script that writes genes down to the messenger RNA and then that is going to translate out to the proteins.
• DNA -> DNA complement strand -> DNA template strand -> mRNA -> tRNA -> Amino Acids
• When trying to find the Amino Acids do you use the mRNA or the tRNA?

  mRNA