Notes 9-30

Notes from today's lecture :)

- Flagella are similar to the ATP synthesis set up of mitochondria and bacteria protons being pumped by the water-wheel apparatus
- Virulence factor – protein causing symptoms in a cell
- Type 3 secretion systems –
o Similar to the set up that spins bacterial flagellum, in turn being similar in a molecular set up to the ATP synthase of bacteria/mitochondria
o Act like a needle to inject virulence factors into the host cells

How are the predictions of evolution different from the predictions of intelligent design?
- Evolution
o Parts of cells have developed from other parts of cells - recycle
o Should see elaborate structures cobbled together by a lot of different parts
- Intelligent Design
o Things weren’t put together out of different parts but were just set up that way from the beginning – they are what they are
o If you took a part out of flagellum it would fall apart and wouldn’t work without every piece of equipment
- Bacterial Flagellum
o Similar to other things in the cell – appears to be more like evolution than intelligent design

Why don’t bacteria have mitochondria?
- Most bacteria are free-living; they DO NOT live on/in a host/in in a host cell
- A definition if NOT a reason – “prokaryotes don’t have membrane-bound organelles, and mitochondria are membrane-bound organelles”
- Bacteria use ATP as energy currency just like ALL OTHER LIVING THINGS
- Mitochondria divide on their own time not with the host cell, and they use the same set of steps that bacteria use to divide
- Because: mitochondria: have their own DNA, replicate on their own using bacteria division steps, & generate ATP in a manner identical to how bacteria generate ATP, && can be killed by many antibiotics if injected directly into the cell
- Biologists believe mitochondria are descendants of bacteria
o Ex. Symbiotic relationship
o Our cells cannot live without mitochondria, which can’t live without our cells

I. Exponential growth vs. logarithmic growth
a. Exponential growth
i. Equation: # bacteria at a given time = 2^x, where x = # of generations since originally had 1 bacterium
ii. Picture on hand out
II. How an individual bacterium divides – what are the limits?
a. Replication of chromosome
i. Replicate it’s DNA: single circular chromosome
1. DNA is copied by enzyme DNA polymerase
2. Need 2 copies of chromosome: 1 for each cell
b. Elongation of cell
i. From circular to oblong – create more in the middle and pushing ends out farther … o → 0 … New cell envelope in the center
1. Pushes copies to opposite ends of the cell
c. Formation of FtsZ ring at septum
i. Pinches the middle of the cell after chromosomes go to opposite sides
d. Building of new cell envelope components at septum
i. New cell components are then built in the middle of the cell finishing off each of the cells and finishing the cell.

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