Exam 1 Practice Questions

• why are glycolysis and kreb's cycle conserved?

  they were present in LUCA
• a prion is an abnormal form of a usually harmless protein
• how is DNA compacted in the nucleoid?

  supercoiling and histone-like proteins
• where are lipopolysaccharides and in which type of cell?

  outer membrane of gram - cell
• what is lipoteichoic acid and what type of cell is it found in?

  anchors peptidoglycan to cytoplasmic membrane, gram + cell
• x-ray crystallography shows macromolecule structure
• chloroplast and cyanobacteria are related
• tRNA are charged with the correct amino acid by tRNA synthetase
• a ribosome has A, P, and E sites for translation
• what is the purpose of FtsZ?

  cell division, found in most bacteria
• viroid: smallest known disease causing agent
• RNA primase: creates RNA fragments for DNA replication
• RNA primers: provide 3' OH for DNA polymerase and synthesis
• DNA A: protein that binds to origin of replcation
• DNA polymerase 3: main polymerase, synthesizes leading and lagging strand
• DNA polymerase 1: removes ozaki fragments
• 16 s rRNA intiates translation by binding to shine dalgarno sequence
• peptidoglycan contains amino acids in the crossbridges
• what is the role of the sigma factor?

  directs RNA polymerase to promoter
• why are flagella better for swimming than pili?


  pili are slower in liquid
• fimbrae are used for attachment
• where is the periplasmic space in gram negative bacteria?

  between cytoplasmic and outer membrane
• where is the periplasmic space in gram + bacteria?

  between cytoplasmic membrane and peptidoglycan
• what occurs in the periplasm?

  enzymatic reactions for energy generation, transport, and motility
• where do eukaryotes start translation and how is that different from prokaryotes?

  start at first AUG because no shine dalgarno sequence
• do archea have peptidoglycan cell walls?

  no, they can have psuedopeptidoglycan
• which domain has polycistronic mRNA and what is it?

  prokaryotes, can transcribe for more than one gene at a time (operons)
• the presence of stable C2 protein triggers lysogeny
• high FtsH triggers lytic
• are archaea more closely related to bacteria or eukarya?

  eukarya
• does facilitated diffusion sue the proton gradient?

  no, because there is no energy cost
• which direction does flagella rotate for movement?

  counterclockwise
• microbes are single-celled, have DNA as a genome, and replicate their genome
• what part of DNA helix is hydrophobic and what part is hydrophilic?

  DNA bases are hydrophobic, phosphate backbone is hydrophillic
• what type of cells use endocytic route in penetration?


  eukaryotes
• what penetration technique is used in bacteria and why?

  bacteriophages inject genome into cell, must bypass cell wall