Bio Midterm

• information


  Shared knowledge (communication or reception of knowledge); signal representing data that justifies a change.
• Categorize different forms of biological information.

  1. Heritable information provides continuity of life.

  2. Non-heritable information is transmitted within and between biological systems.
• What is the most fundamental example of information transfer?

  Reproduction that's regulated at the molecular level.
• Interpret data showing that DNA is the heritable material and protein is not.


  Griffith demonstrated that the "S factor" produced more S cells and its info was being communicated from parent to offspring. Avery extracted water-soluble material to convert r cells -> S cells. Only DNase eliminated the ability to transform the R cells -> S cells. Hershey + Chase blender experiment: infer that sulfur-containing protein has no function in phage multiplication and that DNA has some function.
• Evaluate experimental design and analyze data from research on DNA as molecular information.


  Griffith's mice experiment and his experiment with the cytoplasm and the cell membrane to figure out if it's DNA or protein. Membrane worked but not when washed with a buffer. Avery's robust protocol, centrifuge, and using proteases, RNase, and DNase. compared N/P ratio. Hershey + Chase blender experiment with isotopes of radioactive p (in DNA) and s (in protein). 80% protein not in cell and 70% DNA in cells.
• Explain the differences between S and R Streptococcus pneumoniae.

  Injecting bacteria from R (rough) colonies into mice did not kill them, but injecting bacterial S (smooth) colonies did.
• Compare and contrast the building blocks of DNA and proteins.

  Proteins are composed of twenty different amino acids, whereas DNA and RNA are composed of only four different nucleotides. DNA has nitrogen and phosphorus; proteins don't have phosphorus.
• Explain why amino acids make a better code than nucleotides and why biologists were reluctant to concede that DNA was the heritable material.

  This numerical difference (4 DNA nucleotides versus 20 amino acids) convinced the biologists of Griffith's generation that protein was a logical choice for the genetic code. Proteins studied more.
• biology


  The study of life
• life


  The quality that distinguishes a vital and functioning being from a dead body.
• hypothesis


  a testable prediction
• experiment


  a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact.
• control


  Variable used for comparison, not being tested.

  -Used to verify that you have performed the experiment properly.
• negative control


  A group of data lacking what is being tested so as to give expected negative results.
• positive control


  Group expected to have a positive result, allowing the researcher to show that the experimental set up was capable of producing results.
• deoxyribonucleic acid (DNA)


  A complex molecule containing the genetic information that makes up the chromosomes.
• Nucleotide

  A building block of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.
• Protein


  An organic compound that is made of one or more chains of amino acids and that is a principal component of all cells.
• Amino acid


  Building blocks of protein
• Protease


  enzyme that breaks down proteins
• RNase


  an enzyme that cuts the sugar-phosphate backbone in RNA
• DNase


  breaks down DNA.
• Recognize the structure of DNA, including the nucleotides, double helix and base pairings.


  DNA composed of CHONP, nucleotides (phosphate group, nitrogenous base, and a 5-carbon sugar). second carbon lacks an O. A without (2 h-bonds), C with G (3 bonds). a & g have two rings (purines). C & T are pyrimidines. double helix helps with replication. Watson, crick, Wilkins, stokes, Wilson, Franklin and gosling. 2 strands antiparallel 5' to 3
• Demonstrate how DNA replication is semi-conservative.

  Meselson + Stahl use stable isotopes of N. 2 bands. lighter gets darker.
• Estimate the amount of DNA in a sample by finding the area under a curve.


  Find area under graph using triangles and convert to percentages.
• Determine the number of generations that have passed in a population of cells.

  formula:

  log2x = (log x)/ (log 2)
• Isotope

  Atoms of the same element that have different numbers of neutrons.
• Sulfur

  Hershey and Chase experiment.

  Sulfur was chosen for making radioactive proteins because, unlike DNA, proteins contain sulfur in amino acids cysteine and methionine with each amino acid containing one atom of sulfur.
• phosphorous

  Hershey and Chase experiment.

  Phosphorous was chosen for making radioactive DNA because DNA contains many phosphates.
• bacteriophage


  A virus that infects bacteria
• Occam's razor

  Simpler explanations are more likely to be true than complex ones.
• Monomer


  A simple compound whose molecules can join together to form polymers
• Ribose


  A five-carbon sugar present in RNA
• Deoxyribose


  A five-carbon sugar that is a component of DNA nucleotides
• phosphate


  A natural mineral containing chemical compounds.
• nitrogenous base


  An organic base that contains nitrogen, such as a purine or pyrimidine, a subunit of a nucleotide in DNA and RNA
• hydrogen bond


  A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule.
• antiparallel


  referring to the arrangement of the sugar-phosphate backbones in a DNA double helix (they run in opposite 5' -3' directions).
• X-ray diffraction


  Process used by Rosalind Franklin to make images of DNA that helped reveal the structure of DNA.
• DNA polymerase


  Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule.