AP Biology

Classification & the New Taxonomy

Chapters 25 – 35

AP Biology

Organisms classified from most general group, domain, down to most specific, species domain, kingdom,

phylum, class, order, family, genus, species

Finding commonality in variety

use the mnemonic!

Solar System

Earth

No. America

U. S.

N. Y.

L. I.

Nassau Co.

Levittown

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Archaebacteria&

Bacteria

Classification Old 5 Kingdom system

Monera, Protists, Plants, Fungi, Animals

New 3 Domain system reflects a greater

understanding of evolution & molecular evidence _______________________ _______________________ _______________________

___________________ ___________________ ___________________ ___________________

Prokaryote

Eukaryote

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Kingdom____________

Kingdom____________

Kingdom____________

Kingdom________________

Kingdom________________

Kingdom________________

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The Evolutionary Perspective

AP Biology 2007-2008

Prokaryotes

Domain Bacteria

Domain Archaebacteria

DomainBacteria

DomainArchaea

DomainEukarya

Common ancestor

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Bacteria live EVERYWHERE! Bacteria live in all ecosystems

on plants & animals in plants & animals in the soil in depths of the oceans in extreme cold in extreme hot in extreme salt on the living on the dead

Microbes alwaysfind a way to

make a living!

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Bacterial diversityrods and spheres and spirals… Oh My!

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Prokaryote Structure Unicellular

bacilli, cocci, spirilli Size

1/10 size of eukaryote cell 1 micron (1um)

Internal structure _________________________________

_____________________________ _____________________________

_________________________________ not wrapped around proteins

prokaryotecell

eukaryote cell

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Prokaryote vs. Eukaryote Chromosome

double helix

Prokaryote

Eukaryote

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Variations in Cell Interior

internal membranesfor photosynthesislike a chloroplast(thylakoids)

internal membranes

for respiration

like a mitochondrion

(cristae)

aerobic bacterium

mitochondria

cyanobacterium(photosythetic) bacterium

chloroplast

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Prokaryote Cell Wall Structure

peptide sidechains

cell wallpeptidoglycan

plasma membrane

protein

Gram-positive bacteria

Gram-negative bacteria

peptidoglycan

plasmamembrane

outermembrane

outer membrane of lipopolysaccharides

cell wall

peptidoglycan = polysaccharides + amino acid chainslipopolysaccharides = lipids + polysaccharides

That’simportant foryour doctorto know!

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Major Nutritional Modes

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Prokaryotic metabolism How do bacteria acquire their energy &

nutrients? ___________________

photosynthetic bacteria ___________________

oxidize inorganic compounds nitrogen, sulfur, hydrogen…

___________________ live on plant & animal matter decomposers & pathogens

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Obligate aerobes: cannot grow without oxygen because they need oxygen.

Obligate anaerobes: are poisoned by oxygen. Some use fermentation, where others extract chemical energy by another form of anaerobic respiration.

Facultative anaerobes Oxygen > Use No Oxygen > Fermentation

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Honors Biology 2006-2007

Fermentation (anaerobic) Alcoholic: Bacteria, yeast

1C3C 2Cpyruvate ethanol + CO2

Lactic Acid: Bacteria, fungi, human musclespyruvate lactic acid

3C 3C

NADH NAD+

NADH NAD+

to glycolysis

to glycolysis

AP Biology

Honors Biology 2006-2007

Cellular respiration

2 ATP ~2 ATP 2 ATP ~34 ATP+ + +

~38 ATP

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Genetic variation in bacteria Mutations

bacteria can reproduce every 20 minutes ______________________

error rate in copying DNA 1 in every 200 bacteria has a mutation you have billions of E. coli in your gut!

lots of mutation potential!

Genetic recombination bacteria swap genes

____________________ small supplemental

circles of DNA

____________________ direct transfer of DNA

conjugation

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Bacteria as pathogens Disease-causing microbes

___________________ wilts, fruit rot, blights

____________________ tooth decay, ulcers anthrax, botulism plague, leprosy, “flesh-eating” disease STDs: gonorrhea, chlamydia typhoid, cholera TB, pneumonia lyme disease

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Bacteria as beneficial (& necessary) Life on Earth is dependent on bacteria

___________________________ recycling of nutrients from dead to living

___________________________ only organisms that can fix N from atmosphere

needed for synthesis of proteins & nucleic acids plant root nodules

___________________________ digest cellulose for herbivores

cellulase enzyme

produce vitamins K & B12 for humans

_________________________ from yogurt to insulin

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1st Prokaryotes Domain Archaea: known as

extremophiles and live in extreme environments such as geysers.

Extreme halophiles live in saline environments (highly concentrated with salt).

Extreme thermophiles live in very hot environments.

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Domain Characteristics Examples

Bacteria (Eubacteria)

unicellular prokaryotespeptidoglycan cell wall, cell membrane, ribosomes no membrane-bound organellesnaked DNA, single circular chromosome,asexual reproduction = binary fissionheterotrophs, photoautotrophs, chemoautotrophs rods, spheres, spirals; Gram positive & negative stain

Bacillus, E. coli, Streptococcus Cyanobacteria = “blue-green algae”

Archaebacteria unicellular prokaryotescell wall (no peptidoglycans), cell membrane, ribosomes, no membrane-bound organellesDNA + histone proteins, single circular chromosome asexual reproduction = binary fissionextremophiles: halophiles, thermophiles, methanogens

Methanococcus, Halobacterium, Thermoproteus

AP Biology

1) Contrast the cellular and genomic organization of prokaryotes and eukaryotes.

Lack internal compartmentalization Less DNA Single ring-shaped chromosome Plasmids

2) Explain how rapid reproduction allows prokaryotes to adapt to changing environments.

Rapid reproduction enables a favorable mutation to spread quickly through a prokaryotic population by natural selection.