MIC 102 Middie 2 Exam Questions with Answers

MIC 102 Middie 2 Exam Questions with Answers Building Blocks - Answer-amino acids nucleotides sugars lipids amino acids - Answer-building blocks of proteins different families of aminos can come from diff precursors can predict source of some mutations in central pathways - ex: families of amino acids cant be made and must be supplied nucleotides - Answer-building block of nucleic acids (DNA+RNA) made in activated state and READY for polymerization (they have the energy needed to polymerize themselves) uses lots of energy-reducing power and nitrogen (glutamine) to make these purines - Answer-A G made from ribose-5-P (21 enzymes) Pyrimidines - Answer-T C U made from ribose-5-P and oxaloacetate (24 enzymes) sugars - Answer-used in capsules, cell walls, outer membranes also can contribute to energy/carbon storage - glycogen most of these specialized sugars muct be manufactured from precursors fatty acids and lipids - Answer-major requirement for phospholipids membranes and LPD (lipid A) glycerol for linking fatty acids acids are constructed by adding 2C units to the chains - number of double bonds - chain length - branching - most fluid: short, branching, with more double bonds Macromolecules - Answer-DNA RNA Protein central dogma of molecular biology - Answer-DNA - RNA - Protein genotype - phenotype (encoded by genes) - (expression) DNA Strand - Answer-5' - 3' anti parallel nucleotide bases (attached to backbond) - 1 ring (pyrimidine) - 2 rings (purine) Sugar phosphate backbone w/ OH 3' has what - Answer-OH 5' has what - Answer-phosphate GC bonds - Answer-stronger bc 3 hydrogen bonds AT bonds - Answer-two bonds bc 2 hydrogens weaker than GC Minor groove vs major groove in DNA - Answer-Minor- Area where bases are closer together and not easily accessed Major- Main site of protein building -- gets smaller and compressed w/ coiling & can't fit proteins DNA synthesis - Answer-nucleotides are added by DNA polymerase 3'OH of growing strands reacting with 5'PO if new nucleotides new DNA made when added on to 3'OH overview replication - Answer-begins at oriC sequence continues in both directions towards terC sequence DNA Polymerase III - leading strand is continuous (opposite direction) - lagging strand is discontinuous (Okazaki) *two copies of every gene at places the DNA has been replicated circular chromosomes - Answer-bacteria and archaea initiation of replication - Answer-DnaA binds to DNA at oriC and "melts" the strands - requires ATP to polymerize and wrap around DNA - opens up DNA molecule - once opened, single stranded binding proteins bind to exposed single strands to hold them open -oriC is AT rich (2 H bonds) DnaC loads the helicase DnaB onto the single strands at oriC - process requires ATP DnaB recruits the rest of the "replisome" proteins Replisome - Answer-primase (DnaG) = RNA polymerase - RNA promers needed to start synthesis of DNA poly III = main bacterial DNA polymerase - clamp keeps pol III attached as it moves clamp loader clamps poly onto the DNA strand lays down RNA primer on complementary DNA lagging strand is a bit of a problem... so, loop out a big loop then poly can go at it backwards cell controls initation how? - Answer-needs 1. enough ATP to replicate 2. to be timed well to coordinate with cell growth and division DnaA is the key -- accumulates as cell grows - origin of replication has multiple DnaA binding sites - all of which must be filled to start replication --requires ATP to polymerize and kick off replication