Exam2/quiz 2 Flashcards
(29 cards)
What are the 4 steps to living cells?
- synthesis of small abiotic molecules.
- joining small molecules into macromolecules
- packaging of molecules into protocells droplets w/ membranes that maintained internal conditions.
- origin of self replicating molecules
Synthesis of small abiotic molecules
OILRIG (oxidation = loss of electrons, reduction = gain of electrons), early earth was reducing.
ionic/covalent bonding (single atoms –> small molecules)
Evidence? Miller-Urey experiments / Murchison Meteorite.
Joining small molecules into macromolecules
Carbs, lipids, proteins, etc, turn into functional molecules
Packing of molecules into protocells droplets w/ membrane that maintained internal conditions different form their surroundings
Macromolecules —-> protocells
Why? need functional macromolecules in same place to function together.
How? due to hydrophobic interactions between molecules.
rate increases by producing montmorillonite clay
Origin of self replication
RNA based ( makes complimentary copies of short stretched RNA), protocells produced daughter cells = fossil rock = prok
Characteristics of Prok
small
single cell
no nucleus
membranes bound organism
sometimes an extra layer = gram(-)
comes in three shapes
What shapes do prok come in?
circular “cocci”, rod “bulilli”, spiral/helical “spirelli”
Autotrophs (feeds self)
Photoautotrophs “plant like”: energy = sun, carbon source = CO2 or HCO -3
Chemoautotrophs “unique”: energy = inorganic molecules, carbon source CO2 or HCO -3
Heterotroph (fed by others)
Photoautotrophs “unique”: energy = sun, carbon source = organic molecules
Chemoautotrophs “animal like”: energy = organic molecules, carbon source = organic molecules
O2 usage
aerobic = use oxygen
anaerobic = no O2
facultative anaerobic: dont care
How do prok reproduce?
Binary fission
Where does genetic variation come form in bacteria?
Mutations/ rapid reproduction
Horizontal gene transfer
1. transformation: dead/dying —> living
2. conjugation: living —-> living, utilizes pilli + plasmids
3. transduction: living —-> via phage viruses
relationships within environment symbiotic relationships
Mutualistic: both parties benefit ex. gut
Communalistic: one party benefits, other neither helped or harmed.
Parasitic: one party benefits other is harmed.
(5)Eukaryotes Features
- bigger than prok
- membrane bound organelles
- single celled (protist) or multicellular (fungi, animals, protist)
ribosomes - ribosomes are different than prok
- arose by endosymbiosis
Proof of endosymbiosis?
- structure of free-living prok, euk + membrane-bound organelles are all the same (phospholipid bilayer of embedded proteins)
- mitochondria/chromoplast features that suggest they were once free living prok
both have their own DNA, single chromosomes
have own ribosomes: prok in nature - reproduce by binary fission
Endosymbiosis
Theory that explains the origin of euk cells from prok cells living inside one another in a mutualistic relationship.
“Protist” (not monophyletic)
single celled eukaryotes
What are the 4 super groups
- excavata, features cytoskeleton (basel taxon) ex. euglena
- SAR, stramenopiles, aveolates, rhizarian ex. brown algae, diatoms, paramecium
- Archaeplastida, red/green algae + multicellular plants (photosynthetic)
- unikonta, fungi + nucleorids / animals + choanoflagellates
evolution of multi-cellularity
analogous (1.3 bya —> 635mya)
True multicellularity requires?
- cohesion: cells can stick to each other.
- communication
- differentiation, each cell is differentiated to perform a particular function
How did true multicellularity arise?
Mutation in CCD domain
of genes of an org, does not = complexity
(value paradox)
How do we get multiple proteins from same genes?
- alternative splicing
- reading non-template strand
Functional mfolds
sun/oxygen
plasmids
extra chromosomal DNA, function in conjugation.
