Bio 108 Midterm 2 most challenging terms Flashcards
primordial soup
earth originated through chemical. rxns that gave rise to molecules of life
protocells
packaging of amino acids proteins and nucleic acids
establish homeostasis and metabolism
characteristics of prokaryotes 8
-earliest form of life
-small unicellular
-high metabolic rates
-diffusion sufficent
-diverse organization
-lack mebrane bound nucleas
-diverse shapes spheres (cocci) and rods (bacilli) and spheres
-circular dna
Cell surface structures
prokaryotes
cell wall protection against intracellular fluid
made up of peptidoglycan
semi permeable membrane
Gram stain
Distinguish different tyoes of bacteria based on composition of cell wall
Gram negative- violet stain only peptidoglycan
Gram positive- no violet stain and has thinner layer of peptidoglycan and lippopolysacceride
Capsule prokaryotes
external to cell wall sticky adhesive coat allows prokaryote to stick onto surfaces
help evade immune cells
frimbrae, flagella, pilli
frimbrae small hairlike help stick and flagella long whip like and help to move them forward
pilli-similar to frimbrae, sex pili bring form plastids between prokaryotes
endospores prokaryote
thick coated cell some bacteria form to protect from harsh conditions. Dormant when produced and aren’t released until experience an environmental stress, uv high temps…
Prokaryotes internal organization
lack enclosed membrane and compartmentalization
DNA prokaryotes
smaller then eukaryotes
circular condensed genome
some bacteria have small circular dna called plasmids
prokaryotes reproduction
asexual
binary fission
Genetic recombination
transformation
transduction
conjugation
Transformation- external dna taken up by prokaryote. prokaryote dies it releases dna and plasmids which is taken up by other prokaryote
Transduction- phages viruses carry bacteria from one cell to another
Conjugation- touch each other physically direct transfer of DNA
Prokaryotes metabolism
anabolism-build up molecules to release energy
catabolism- break down molecules to release energy
prokaryotes domain bacteria
-proteobacteria
-chlamdydia
-spirochetes
-cyanobacteria
-gram postive bacteria
proteobacteria
gram negative
different types alpha, beta
believed that alpha proteobacteria is related to eukaryotic hosts
mitochondria evolved from aerobic alpha proteobacteria endosymbiosis
Chlamydia
gram negative parasite
excslusively on animal cells
cyanobacteria
first to generate oxygen
chlorplasts in eukaryotes evolved through endosymbiosis of cyanobacteria
Gram positive prokaryotes
gram positive stain
decomposers and some dangerous pathogens
Archaea prokaryotes
methanogens-produce methane as a waste product
extreme halophiles-inhabit highly saline environments
extreme thermophiles- inhabit extreme temperatures and autotrophs
biomediation
eliminating pollutant by organism (prokaryotes) by nitrogen fixation
features of eukaryotes
-linear dna
-membrane bound organelles
-cytoskeleton and cellular dynamics
-sexual reproduction
-two types of life cycles
unicellular- alternation of haploid n and diploid 2n
multicellular- eukaryotes have distinct organs for gamete production
3 steps of endosymbiont theory
- plasma membrane formed around membranes- ER and nuclear envelope
- endosymbiont relationship formed between the host prokaryote and the aerobic prokaryote symbiont (likely proteobacteria) use symbiont for energy-mitochondria
- On one lineage other endosymbionts incorporated such as cyanobacteria-chloroplasts
primary endosymbiosis
secondary endosymbiosis
prokaryote is engulfed by another organism
eukaryote is engulfed by another eukaryote
Protists
Excavata cluster
SAR cluster
Archaeplastida
Amorphea