September 25, 2009
We discuss bacterial growth and the relationship between mitochondria and bacteria.
YouTube video we watched last class:
Bacteria flagellum is comprised of basal body that connects to all layers of the cell membrane, breaks down ATP into ADP and uses the energy freed from that reaction to pump flagellin filament molecules out acrossed the hook where those flagellin filament molecules spontaneously polymerize into a flagellum relatively rigid sort of curvy structure that can then be spun like a propeller on a boat
The energy used to spin that is through a proton pump system; protons are pumped acrossed the plasma membrane into a space between the cell wall and plasma membrane. The pumping of those protons then allows those protons to fall across a water wheel mechanism in the bottom part of the basal body of the flagellum. The falling across the water wheel mechanism is going to spin the flagellum around like a record baby right round right round.
Last time…..
Why is it that bacteria don’t have mitochondria? (have to do with how flagella spin)
Flagella can spin because of a proton pump mechanism
Why do eukaryotes have mitochondria?
Mitochondria are used for, by our cells, ATP!
Mitochondria make ATP by: (Picture of Mitochondria and a cross section of mitochondrian)
*Using electron passes down protons embedded in membrane to pump protons across inner membrane to space in between the two membranes
*then since H+ charged, so cant cross hydrophobic membranes just anywhere so protons fall across water wheel-like proteins in inner mitochondrial membrane to equalize H+gradient
*every time H+ falls across gate, waterwheels spins adding 1 phonsphate to adenosine three falling protons=phosphates added=1 ATP
Take out piece of paper and write down why bacteria don’t have mitochondria?
V. Similarity to type three secretion systems:
*these secretion systems are used to pump proteins outside of bacteria cells
Ex. Virulence Factors pumped directly into host cells thru type 3 secretion systems by some pathogenic (disease causing) bacteria.
Virulence Factors-Proteins that contribute to symptoms of disease made by pathogenic bacteria
Bacterial Growth
1. You have a bacterium, and that bacteria divides, and then those bacteria divide, and those bacteria divide
2^X Exponential Growth=number of bacteria at a given time
The X=number of generations since originally had 1 bacterium
