Module 2 Flashcards
precursor simple cells arose
4.2 and 3.85 BYA
Process of abiogenesis
Simple compounds (H2O, NH3, etc), come together to form small organic molecules (ex: nucleotides); which form to make polymers (RNA, polysac); RNA makes proteins and lipds form spheres (DNA, proteins); formation of protocell, enclosed in lipid membrane
Atmosphere of Old Earth was…
Methane, ammonia, hydrogen…similar to atmospheres of outer planets, no oxygen
Test of abiogenesis theory
Done by Stephen Miller and Urey to test Oparin’s gases present at Old Earth, electric spark was ran through gases and few amino acids were produced in the presence of UV light and water
Photosynthesis originated in aquatic bacteria with ___ instead of water as electron donor
H2S, hydrogen sulfur, released sulfur into the air instead of O2
What happened when aquatic bacteria used water as electron donor for photosynthesis?
released O2 into the water, bubbled into the air, lowered CO2 in the pre-life atmosphere. Ozone was formed from oxygen, protected from UV rays, explosion of life
Prokaryote
single celled organism that lacks a nucleus and membrane-bound organelles
Eukaryote
nucleus and membrane bound organelles, much bigger than prokaryotes
Two domains of prokaryote
Bacteria and Archaea
Archaea are more closely related to…
Eukaryotes
Bacteria cell wall composed of…
peptidoglycan
Archaea cell wall composed of…
proteins
Do Archaea use chlorophyll?
No
Bacteria and archaea both have…
cell membrane, cytoplasm, DNA and ribosomes
What type of chromosomes do prokaryotes have?
One circular chromosome
Nucleoid
region where DNA is located, along with RNA and some proteins , no membrane
Plasmids
at least one, circles of DNA apart from chromosome
Ribosomes
use RNA to assemble proteins, every ribosome makes proteins the same way, structurally different
Cell Wall
gives shape to bacteria and archaea
3 types of bacteria
Coccus, Bacillus, Spirillum
Cell walls of bacteria have a outer layer that…
triggers immune reactions, used for protection or disease
Slime layer or Capsule
Sitcky layer that may surround the cell wall, used for attachment to surfaces
Pili
short hairlike projections made of protein, adhere to objects if attachment pili
Sex pili
aid in transfer of DNA from cell to cell
endospore
dormant, thick walled structures that can survive harsh conditions, will reproduce when conditions become more favorable
chemotrophs
oxidize inorganic/organic chemicals, fungi and animals
facultative anaerobes
can live with or without O2, in absence of O2, use fermentation or anaerobic respiration
Proteobacteria
photosynthesis bacteria, uses purple pigments, includes E coli and Salmonella and ulcer
Cyanobacteria
also photosynthesis bacteria, use green pigments
Spirochaetes
spiral shaped organisms, Lyme disease and syphilis
Actinobacteria
soil dwelling microbes that produce streptomycin
What type of organism does nitrogen fixing (changing atmospheric nitrogen to something plants can use)
Archaea
First cells from domain Eukarya descended from their prokaryotic ancestors at least…
1.5 BYA
What type of cell was mitochondria before it was engulfed?
Proteobacteria
Where did the chlorplast come from according to the endosymbiont theory?
Cyanobacteria
All eukaryotic cells have…
mitochondria
When did multicellularity arise?
1.2 BYA
What is a protist?
eukaryotic organism that doesn’t fit the plant, animal or fungi definitions
algae
general term that refers to photosynthetic protists that live in water
Cells of algae contain chloroplasts that have…pigments
yellow, gold, brown, red, or green
Dinoflagellates
marine protists, have 2 flagella of different lengths, can infect shellfish due to toxins
Diatoms and Brown Algae have…pignments
golden or brown
Diatoms
unicellular algae with two part silica cell walls that fit together
Brown Algae
largest and most complex protists, multicellular algae, has a combination of photosynthetic pigments producing brown color
Red Algae
has photosynthetic pigments that absorb wavelengths of light that chlorophyll a cannot capture
Famous uses of Red Algae
agar plates and carrageenan
Green Algae
protists with the most similarities with plants, closet living relatives, unicellular or mulitcellular
Water molds
protists that decompose plants and animals in moist environments, secrete digestive enzymes into their surroundings but cell walls are made with cellulose
Irish potato famine was caused by…
water molds on potatoes
Slime Molds
protists that live in damp habitats
Fungi characteristics
eukaryotic, heterotrophs, cell walls made of chitin, storage carb is glycogen, most are multicellular but yeast is unicellular, only diploid cell is zygote