biodiversity unit 2

gram positive

gram positive

retains stain better, purple, thick wall of peptidoglycan

gram negative

looks pink, thinner wall of peptidoglycan, also has outer layer of phospholipids

microbiology

study of microbes

microbes

microscopic organisms

coccus/cocci

spherical shaped bacteria

ballicus/bacilli

rod shaped bacteria

spirulus/spirilli

spiral shaped bacteria

alpha, beta, gamma, delta, epsilon

five lineages of proteobacteria

mitochondria

alpha proteobacteria descendant

soil bacteria;nitrosomonas

beta proteobacteria

myxobacteria; drought resistant spores

delta proteobacteria

gastrointestinal parasites; heliobacter

epsilon proteobacteria

endosymbionts

live as parasites inside animals cells, get nutrition form the host

spirochaeles

long corkscrew shape, unusual flagella, produce ATP via fermentation

William Augustus Hinton

bacteriology & pathologist that developed tests for syphillis

cyanobacteria

independent chains or colonies, responsible for nitrogen fixation

nitrogen fixation

heterocytes from cyanobacteria converts nitrogen gas to ammonia then incorporates it into an organic compound with an amino group that humans are then able to intake

heterocytes

part of cyanobacteria that lack PSII, they have no O2 evolution, makes them able to cause nitrogen fixation

gram positive bacteria

independent cells, chains, colonies; major decomposers in soil

plasmids

smaller extrachromosomal rings of DNA, replicate independently of genome, can be transferred between bacterial cells during conjugation, can provide resistance to antiobiotics, and make bridges between other bacteria

binary fission

method bacteria use to reproduce; asexual reproduction by the separation of a body into 2 bodies

transformation

takes up DNA from the environment

conjugation

formation of cytoplasmic bridge; facilitates transfer of plasmids (F plasmids) that contain genes to make sex pillus

transduction

DNA is moved by a virus (bacteriophage)

phototrophs

use light energy to promote electrons to top of electron transport chain; ATP produced by phosphorylation

chemoorganotrophs

oxidize organic molecules with high energy potential

chemolithotrophs

oxidize inorganic molecules with high energy potential

autotrophs

manufacture their own carbon containing compounds from inorganic carbon sources

heterotrophs

grow using carbon containing products of other organisms

photoautotroph

organism that gets it energy from light (photosynthesize) and can synthesize its own organic materials from CO2 and H2O

photoheterotroph

gets its energy from sunlight but cannot use CO2 as carbon source, has to get organic molecules from surrounding environment

chemoorganoautotroph

gets energy from organic compound (synthesized inorganically) that it produced, can use CO2 to synthesize organic compounds

chemoorganoheterotroph

get energy from oxidizing organic compound in environment, breaks it down for energy, cannot use CO2 from environment, has to get carbon from other sources like lipids, carbohydrates…

chemolithoautotroph

gets energy by oxidizing an inorganic compound, gets carbon from utilizing CO2

chemolithoheterotroph

oxidizes inorganic compound for energy, uses reduced organic compounds for carbon source

pathogenic bacteria

bacteria that can cause disease, come from many lineages, result of horizontal gene transfer

virulence

ability to infect another cell; heritable trait that varies in individuals

Koch

discovered germ theory

germ theory

infectious diseases are caused by bacteria and viruses

Koch Postulate

confirms causative link between specific infectious disease and a specific microbe

1. microbe has to be present in sick people, and absent in healthy

2. organism must be isolated and grown in pure culture in lab

3. if injected into an animal, the animal must show symptoms of the disease

4. take the diseased animal and re isolate the microbe again to grow in culture again to prove its the same as the original microbe

antiobiotics

derived from other bacteria to fight bacteria; bacteria competition

enrichment cultures

cells are sampled from environment and the grown under specific conditons; cells that thrive will increase in the number of them so that they can be isolated and studied in more detail

direct sequencing

technique for documenting presence of bacteria that cannot be grown

isolate genes using PCR, genes sequences are compared with other sequences in existing databases

steps: collect sample, amplify genes using PCR, purify genes, amplify genes using E coli, purify genes, sequence them and compare

Carl Woese

compared rRna in many species, found archaea

lactic acid bacteria used to manufacture dairy products

bacteria role in food production

antiobiotics, probiotics, drugs, vaccines

bacteria role in medicine

genes can be injected into plants to make them resistant to pests, some can also clean up oil spills

bacteria role in genetic engineering

polymerase chain reaction (PCR)

basis formed by polymerase from thermophile bacterium, allows duplication of genes starting with a single molecule

bioremediation

use of bacteria and archaea to degrade pollutants

fertilizing

encourages growth of bacteria and archaea to degrade toxic compounds

seeding

adds specific bacteria and archaea to contaminated sites

nitrogenase enzymes

organisms capable of converting molecule N2 → NH3

nitrogen fixation, decay, nitrification, denitrification

nitrogen cycling

causes serious pollution, when in soil bacteria us NH3 as food, they release NO2- or NO3-, this decreases O2 causing anaerobic dead zones, especially bad in aquatic conditions from run off

ammonia fertilizer consequences

chains

strepto

pairs

diplo

four cells

tetrad

irregular clusters

staphylo

sarcinal

cuboidal of 8 or more cells

R plasmid

responsible for drug resistance in bacteria

F plasmid

helps transfer genetic material from one bacteria to another, exchange happens through conjugation

evolution of nucleus hypothesis

derived from infoldings of plasma membrane; membrane infoldings as it increases the surface area to volume ratio

endosymbiosis theory

proposes that mitchondria originated when a bacterial cell took up residence inside a eukaryote

symbiosis

when individuals of two different species live in physical contact

endosymbiosis

when an organism of one species lives inside an organism of another species

size of average bacterium, cell division occurs by fission, have their own ribosomes to manufacture their own proteins which resemble bacterial ribosomes in size, have doulbe membranes consistent with engulfing mechanism

evidence for endosymbiotic origin of mitochondria

Excavata, SAR clade, ArchaePlastida, Unikonta

4 supergroups of Eukarya

Excavata distinguishing morphological feature

pronounced feeding groove

Diplomonads

excavata, two nuclei, multiple flagella, causes Giardiasis, intestinal infection

Parabasalids

excavata, unique internal support rod, most are anaerobic, found in guts of termites and cockroaches, help them digest wood

Trypanosoma brucei

phylum, euglenozoa, excavata, causes african sleeping sickness, parabasal body, free flagellum

Euglenids

excavata, supportive network of interlocking proteins beneath cell membrane, ingest bacteria, 1/3 photosynthetic, can synthesize carbohydrate called paramylon, some have light- sensitive eyespots and use flagella to swim toward light, reproduce asexually

water molds, diatoms, brown algae

Stremenopiles

hair flagella at some point in their life

stramenopiles distinctive trait

absorptive feeding

enzymes are released from organism that dissolves the organisms around it; simpler compounds get ingested; nutrients taken up directly from environment

detritus

dead organic matter

decomposers

protists that live by absorptive feeding

parasites

organisms that live inside other organisms and absorb their nutrition directly from environment in host, causes damage to host

Oomycota (water molds)

stramenopile, unicellular, cell walls of cellulose, freshwater decomposers typically, spores produced sexually or asexually, important decomposers in aquatic ecosystems, also responsible for plant diseases (irish potato famine)

Diatoms

stramenopiles, unicellular or chains, glassy shells, photosynthetic, reproduce sexually or asexually, only sperms have flagellum, base of food chain, important producer of carbon

diatoms (diploid)

gametic meiosis

Phaeophyta (Brown Algae)

stramenopile, photosynthetic, reproductive cells are motile (hairy flagellum), all species are multicellular, produced via sexual reproduction (zygotic meiosis), exhibit alternation of generations

algae body

thallus

brown algae “leaves”

blades

holdfast of brown algae, like a root (but not a root)

stipe

alternation of generations

one phase of lifecycle is based on haploid form and another is based on diploid form

gametophyte

multicellular haploid form; produces gametes by mitosis

sporophyte

multicellular diploid form, specialized cells undergo meiosis to produce haploid cells called spores

spore

single cell made through meiosis; cells grow into a male and female then combine into a zygote

heteromorphic

changes different shapes during mitosis and meiosis

isomorphic

same shape throughout meiosis and mitosis, sporophyte and gametophyte are the same shape

alveolates distinguishing trait

small sacs located under plasma membranes (alveoli)

alveolates

Dinoflagellates, Apicomplexans, Ciliates

Dinoflagellates

aveolate, some capable of bioluminescence, half photosynthetic other parasitic or predatory, , produce oxygen in water, responsible for harmful algal blooms, cell wall made of celullose plates, two flagella; girdle

asexual reproduction

protists undergo ------ routinely

sexual reproduction

protists undergo ----- only intermittently

importance of sexual reprodcution

sex gives new combos of genes, combats diseases and viruses that can mutate quickly, natural selection favor host individuals withs new genotypes

harmful algal blooms

dinoflagellates reach high densities in aquatic environment (produce toxins)

algal blooms of dinoflagellates

red tides

hepatoxins

kill liver cells