Biology 1002B Lecture Notes - Lecture 12: Noncoding Dna, Euglena, Genome Size

46 views2 pages
Biology Lecture 12 (Feb. 15, 2016)
TOPIC: Evolution of Eukaryotes
Factors driving development of aerobic cells
- Earliest bacteria were anaerobic (there was no oxygen in the atmosphere)
- Then cyanobacteria developped; we get oxygenic photosynthesis
- Drives the evolution of bacteria that undergo aerobic respiration
Identify the paradox for why prokaryotes are biochemical complex don't develop morphological
complexity
- Big difference is the ability of eukaryotes to drive more energy than prokaryotes
- Bacteria lack the complexity that you find in eukaryotes… if evolution is stepwise then
why are archaea and bacteria stuck in their simple life?
o Morphological complexity is only found in eukaryotes
- Complexity essentially comes down to eukaryote’s ability to be more energy efficient
Relationship between surface area and volume as cells get larger
- Volume increases much faster than surface area does
- It takes much more energy to support the bigger
volume but you don’t increase your surface area
very much; can’t have as many oxidative
phosphorylation units
- Eukaryotes have giant membrane surface area;
hundreds of mitochondria per cell so you have
lots of oxidative phosphorylation units
- This could be what restricts the size of bacteria;
cell can’t get bigger because you don’t have
enough energy to support the size
o However, this doesn’t explain the
difference between cyanobacterium and aerobic bacterium
o Aerobic bacterium have a huge surface area (internal folded membranes)
- There are bacteria that are much bigger than typical eukaryotic cells (e.g. thiomargarita)
o Have lots of oxidative phosphorylation units
Basis of the Proton Motive Force (PMF)
- Two parts make up the proton motive force:
o Charge difference (voltage)
o Concentration difference
- Can use the proton motive force to drive ATP synthesis or other things
Relationship between chemiosmotic membranes (units) and need for genes to code for its
proteins
- Genes required for chemiosmotic membranes need to be close to the membranes
themselves because the proteins in membranes break down frequently
- Having the genes in close proximity is important so the protein can be synthesized there
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows half of the first page of the document.
Unlock all 2 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Earliest bacteria were anaerobic (there was no oxygen in the atmosphere) Then cyanobacteria developped; we get oxygenic photosynthesis. Drives the evolution of bacteria that undergo aerobic respiration. Identify the paradox for why prokaryotes are biochemical complex don"t develop morphological complexity. Big difference is the ability of eukaryotes to drive more energy than prokaryotes. Bacteria lack the complexity that you find in eukaryotes if evolution is stepwise then why are archaea and bacteria stuck in their simple life: morphological complexity is only found in eukaryotes. Complexity essentially comes down to eukaryote"s ability to be more energy efficient. Relationship between surface area and volume as cells get larger. Volume increases much faster than surface area does. It takes much more energy to support the bigger volume but you don"t increase your surface area very much; can"t have as many oxidative phosphorylation units. Eukaryotes have giant membrane surface area; hundreds of mitochondria per cell so you have lots of oxidative phosphorylation units.

Get access

Grade+
$10 USD/m
Billed $120 USD annually
Homework Help
Class Notes
Textbook Notes
40 Verified Answers
Study Guides
Booster Classes
Class+
$8 USD/m
Billed $96 USD annually
Homework Help
Class Notes
Textbook Notes
30 Verified Answers
Study Guides
Booster Classes