SBI3U Unit 1

facultative anaerobe

grows with or without oxygen

archaea

not pathogenic

methanogens

archaea that live in digestive tract of many animals where they produce methane

extremophiles

lovers/tolerates extremes.

thermophile

heat lover

halophile

salt lover

acidophile

acid lover

bacteria

second oldest life forms

very adaptable—found in all of earth's ecosystems.

most abundant life form

shapes

cocci, bacilli, spirillium

form aggregations

diplo-, strepto-, staphylo-

diplo-

pairs

strepto-

chains

staphylo-

clusters

cocci

spherical

spirillium

spiral

bacillus

rod shaped

autotroph

self feeding

photosynthesis

cyanobacteria

cyanobacteria

photosynthesize

may have been responsible for adding oxygen to early earth, changing atmosphere and direction of evolution

powers food chain.

chemosynthesis

food from chemicals.

chemosynthesis details

like photosynthesis, instead powered by chemicals.

used deep underground where there is no sunlight.

methane and sulfides which burst through earth's crust through hydrothermal vents are used by chemo-synthesizing bacteria.

organisms either eat the bacteria or provide a home for them and use their energy.

heterotroph

eat other things

decompose other organisms

cell wall

made up of peptidoglycan (achilles heel): combination of protein and polysaccharides (sugar)

give them strength and rigidity

gram stain test

bacteria are stained with a dye called crystal violet

gram positive bacteria

purple--thicker cell wall: peptidoglycan retains stain, no extra membrane.

cons of gram stain test

acid-fast and gram-variable bacteria do not respond to gram staining.

acid-fast bacteria

have a cell wall which retains stain well.

gram-variable bacteria

appear pink and purple.

WHY IS IT IMPORTANT FOR DOCTORS TO KNOW WHAT TYPE OF GRAM BACTERIA YOU ARE INFECTED WITH?

help them know what type of infection you have

what antibiotics to treat it with

pili

tiny hair-like structures found in bacteria

helps bacteria stick to surfaces and form conjugation bridges

membrane

inhibits the uptake of antibiotics

helps stabilize inner membrane (less need for cell wall)

chromosome

a single loop of DNA that is folded on itself

controls cell's function

genophore

Nucleoid

not an actual nucleus!!!!!!!!

just the region where dna is found

Plasmid

small loop of DNA outside nucleoid

responsible for: conjugation, antibiotic resistance

capsule

found outside some bacteria

protects bacteria from external environmental conditions and stores nutrients.

layer of polysaccharide

outer membrane

protects cell wall in Gram negative bacteria

cell membrane

controls flow of nutrients between cell and environment

ribosomes

do protein synthesis

flagellum

rotate by means of a "motor" in cell envelope.

allow for motility

sensory purposes

storage granule

stores nutrients

binary fission

asexual reproduction

parent cell —> two identical daughter cells

reproduction, cell lacks a nucleus

occurs quickly under ideal conditions ~20 minutes

mitosis

growth in multicellular organisms, cell has a nucleus.

binary fission stages

1. cell grows, bacteria copies its chromosome

2. cell elongates, chromosomes separate, septum begins to form

3. septum complete and cells divide

conjugation

one cell links to another by a pilus (pilli) and transfers a copy of all or some of its chromosomes

not sexual reproduction

results in new genetic combinations

why is conjugation bad

bacteria with a genetic resistance to antibiotics can pass its DNA to another bacteria

bacteria: role in ecosystem

decomposers, nitrogen fixation, producers

CHNOPS

Carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur

bacteria as decomposers

recycle nutrients back to environment from dead organisms

no decomposers = elements would have remained in dead organisms and life would have ceased

nitrogen fixation

bacterial enzymes allow them to convert nitrogen from air into a useable form

bacteria as producers

form basis of food chain

Symbiotic bacteria

help host organisms

guts of herbivores: aiding digestion of cellulose

guts of humans: aid digestion and produce vitamins

Pathogenic bacteria

organisms that cause disease caused by toxins released by bacteria

commensal relationship

live in us but don't harm us

streptococcus (some)

mutualistic relationship

live in us and help us

parasitic relationship

live off of our nutrients

Antibiotics

chemicals that kill bacteria or prevent reproduction (infection)

revolutionized how we treat diseases (in a good and bad way)

we need to control the use of existing antibiotics, create new ones, combat bacterial resistance

antibiotics cons

overuse + misuse of antibiotics = more resistant bacteria

antibiotics overuse/misuse examples

antibiotics being used to attack viruses (doesn't work because viruses have a protein coat)

use of antibiotics in agriculture: helps livestock grow faster

why its important to finish antibiotics?

so they are all killed and don't start multiplying again.

Similarities of archaea and bacteria

use conjugation for adaptation, similar shapes and form aggregations, asexual/binary fission

Differences of Archaea and Bacteria

important genetic differences and makeup of RNA

bacteria: peptidoglycan in their cell walls, create endospores,

archaea: unique enzymes allow archaea to live under extreme conditions, resistant to antibiotics because they lack peptidoglycan

obligate aerobe

grows with oxygen

obligate anaerobe

killed by oxygen

aerotolerant anaerobe

don't care about oxygen (don't need it for growth)

bacteria eyes?

no, but they have receptors on their cell surface which can detect changes in their environment.

staph

pimples, pneumonia

found on skin, nose, mouth

GOOD E. coli

digest food + make vitamins

BAD E. coli

in raw meat causes food poisoning

ingested anthrax

infected, undercooked meat.

inhaled anthrax

dried spores are inhaled, most dangerous form, must be treated early.

endosymbiosis

explains how eukaryotic cells evolved from symbiotic relationships between two or more prokaryotic cells.

cell organelles

aerobic bacteria —> mitochondria, cyanobacteria —> chloroplasts

endosymbiosis stages

1.start with two independent bacteria

2.one engulfs the other

3.one survives and lives inside the other now

4.internal bacteria are passed on from generation to generation

both bacteria benefit

endosymbionts benefit by getting safe home and nutrients

host cells benefit by getting some energy released by endosymbionts

evidence

mitochondria and chloroplasts: have separate circular DNA similar to prokaryote DNA, reproduce through binary fission

Eyepiece or ocular lens

First lens which you look through: 10x

Body Tube

Keeps the two sets of lenses the correct distance apart.

Revolving Nose Piece

Allows user to change objectives. Hold lenses.

Objective Lens

Increases magnification.

Low objective lens

4x

Medium objective lens

10x

High objective lens

40x

Stage

Where slide is placed.

Diaphragm

controls amount of light that hits slide.

Condenser Lens

focuses light hitting the slide.

Light

Provides a light source.

Fine Adjustment Knob

Sharpens the image. Slowly moves the stage.

Coarse Adjustment Knob

Moves the stage quickly.

Stage Clips

Holds the slide in place.

Arm

Supports the body tube.

Base

Supports the microscope from the bottom.

microscope rules

Keep stage dry

Return to 4x objective.

Higher resolution = Fine adjustment knob.

Resolution

Measure of clarity.

classification

grouping organisms based on shared characteristics

organize and indicate evolutionary relationships.

biological species concept

If two organisms can mate naturally and produce fertile offspring, they are the same species.

biological species concept pros and cons

PROS

Simple, widely used

CONS

Can't apply to asexual and extinct organisms

biological species concept example

Donkey + Horse = Mule. Mule can't reproduce. therefore, donkeys and horses are different species.

morphological species concept

characterizes a species by body shape and other structural features

morphological species concept pros

Simple

Applied to asexual and extinct organisms

morphological species concept cons

Subjective: deciding how much variation is acceptable in a species.

Many organisms have similar characteristics.