lecture04 - 20.106J Systems Microbiology Lecture 4 Prof...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
20.106J – Systems Microbiology Lecture 4 Prof. Schauer ¾ Reading for today: Chapter 6 – On Growth ¾ Problem set due today ¾ Today: Growth – in microorganisms it’s different from in metazoans – increase in number of organisms instead of size o Binary fission o Other methods: Organisms that replicate their DNA many times over, than split into many parts at once ¾ Next week: metabolic regulation Binary Fission o Time from bacterium to bacteria is a generation o Generation time is how long it takes o 20 minutes is a rather fast generation time. 8 minutes is the world record. o We look for bacteria that can replicate fast, or that can replicate in extreme conditions. o Cell content replicates before division. Fts proteins and the “divisome” o FtsZ aligns before division o The most intense signal occurs at the center edges due to the 3- dimensional shape Peptidoglycan synthesis o Peptidoglycan needs to be extgended for the cell to grow o The balance needs to be right, so cell integrity isn’t compromised o Antibiotics bind to DNA binding proteins like FtsI, so that those enzymes aren’t available for the peptidoglycan synthesis, and the bacterium lyses. (Autolysins without autolysis) o The FtsZ ring leaves a scar in the cell wall, which you can see later Peptidoglycan structure o Two planes with cross-links in between. These cross-links give it its integrity o MreB allows a variety of shapes -- not just spheres Exponential Growth o Because bacteria undergo binary fission, they can replicate into mind- boggling numbers very fast (exponential rate) o
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern