Class notes
Bio 102 Exam 2 Review Notes
- Course
- BIO 102
- Institution
- University Of Rhode Island
This is a comprehensive and detailed review note on Exam 2 for Bio 102. *Essential Study Material!!
[Show more]
Seller
Follow
Content preview
Energy Sources: microbial and Metabolic DiversityProkaryotic Diversity
-oldest, structurally simplest, and most abundant forms of life
-abundant for over a billion years before eukaryotes
-90 to 99% unknown and undescribed
-ess that 1% cause disease
-fall into 2 domains
-bacteria (also called eubacteria)
-archaea (formerly called archaebacteria)
-many archaeans are extremophiles (live in extreme environments)
→ the morning glory pool, a hot spring in yellowstone national park
Prokaryotes are different that Eukaryotes
-unicellularity
-only eukaryotic cells can be multicellular
-prokaryotes may stuck together to form associations and biofilms
-cell size
-size varies tremendously (generally much smaller than eukaryotes)
-nucleoid
-prokaryotic chromosome is single, circular, double stranded DNA
-found in the nucleoid region of the cell, often have plasmids.
-cell division and genetic recombination
-most divide by binary fission, don’t go through mitosis
-exchange genetic material extensively
-genetic recombination
-occurs through horizontal gene transfer, no sexual reproduction
-not a form of reproduction
-internal compartmentalization
-prokaryotes have no membrane-bounded organelles
-ribosomes differ from eukaryotic cells
-metabolic diversity
-bacteria and archaea are the masters of metabolism
-occupy a broad range of environments=diverse metabolic processes
Requirements of living organisms
-ATP (energy)
-a source of carbon (C-C bonds)
-some additional nutrients
What is so special about O2?
Oxygen is highly electronegative and so is an efficient electron acceptor
,Acquisition of Carbon and energy
Metabolic Diversity
, -Methanogens decompose organic matter when all the other electron acceptors run out
-the microbes that live at hydrothermal vents are examples of extremophiles
Cyanobacteria performed the first photosynthesis
-precambrian cyanobacteria formed mats called stromatolites
The oxygen revolution
-all organisms were small for 3 billion years. Life got big in just 50 million years (1/60th of total
time life had existed)
-cyanobacteria were responsible for changing the earth's atmosphere to one with a high
concentration of oxygen
-no free molecular oxygen existed for the first 2.3 billion years of earth's history
Cyanobacteria and early life
Changed the path of evolution on earth
How did eukaryotes gain the ability to respire (cellular respiration) and produce oxygen (in
photosynthesis)?
Endosymbiosis and the origin of mitochondria
-endosymbiosis theory:
-mitochondria originated when bacterial cells took up residence inside another cell about
2 billion years ago
-symbiosis: individuals of two different species live in physical contact
-endosymbiosis: an organism of one species lives inside the cells of an organism of another
species
-evidences of endosymbiosis theory:
-mitochondria similar size to α-proteobacteria
-mitochondria replicate by fission
-mitochondria have their own ribosomes and manufacture their own proteins
-mitochondria have double membranes
-mitochondria have their own genomes:
-organized as circular molecules
Not all plastids in eukaryotes are derive directly from primary endosymbiosis
Evidences for endosymbiotic origin of chloroplast
-chloroplasts have bacteria like characteristics like mitochondria
-many endosymbiotic cyanobacteria live in eukaryotes today
-chloroplasts have circular DNA with genes similar to those in cyanobacteria
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller anyiamgeorge19. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
75619 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now