Chapter 28 Microbes Flashcards
Ways microbes save the world
- Probiotics - promote internal flora and bacteria (salamanders use antifungal bacteria to protect eggs on skin
- Cultured bacteria used to combat CHYTRID bacteria, sceralize amphibian skin
- Dehalococcoides can break PCE and ICE into ethane (ground water problem)
Ways microbes save the world pt 2
- Wholbachia are symbiotic bacteria
(Mutualist/parasitic) in mosquitos but not the malaria causing - Greenhouse gases - bacterial methanophilies - metabolize CO2, methane, water vapor - floor temp increase, ice caps melting which trap methane
Eukarya
- Membraned nucleus
- linear DNA chromosome w/ protein organization
- mitosis & meiosis
- endomembrane system
- mitochondria and plastids (not all)
- structurally similar to prokaryote cell wall
- cytoskeleton (shape changing, movable internal components, 9+2 arrangements in the flagella)
Endosymbiotic theory
a) aerobic heterotrophic prokaryotes engulfed to become mitochondria
• alphaproteobacteria - mitoch. ancesto
b) photosynthetic prokaryotes engulfed as plastids (chloroplast)
• occurred later after mitochondrial development
• Cyanobacteria - plastid ancestor
Evidence of symbiosis
Enzyme heavy inner plasma membrane
& transport chains (modern prokaryote)
• similar splitting to binary fission of prokaryote
• circular bodied DNA not associated w/ proteins
• tRNA, ribosomes, for protein synthesis
• move more similarity to pro than euk
Protista diversity
A) historical perspective - discovery of new organisms and development of more accurate descriptions
Was originally paraphyletic
Protist diversity cont.
B) current hypothesis
Eukaryotic tree demonstrative off process of science (root is uncertain) and shows all 4 branching at the same time
• 4 main groupings of eukaryotes
1) excavata
Similarities in cytoskeleton morphology
• most have excavated groove used for feeding
• molecular evidence supports the mono phyletic arrangements of groups working
- lack plastids w/ modified mitochondria (mitosomes)
- anaerobic respiration
- 2 equal size nuclei
- multiple flagella
- inhibits intestines of mammals
Giardia intestinalis
EXCAVATA
- use flagella for movement unique structure due to special crystalline/spiral rod
- have a single large mitochondria with mass of DNA called kineto plastids
- heterotrophic specific to humans
- Tsetse fly - African sleeping sickness
- Rebuuid kissing bug - Chagas’ disease
- use bait and switch method of surface proteins for enhanced immunity to humans
Trypanosoma Spp.
EXCAVATA
- DNA evidence supports this super group but more recently informally named
- 3 main branches
- some evidence that the ancestor of the name
The SAR clade
Photosynthetic protist, unicellular algae
• glass like silica wall
• highly diverse (100,00+ species)
• CO2 sequesterer
Diatoms (bacillariophyta)
SAR CLADE
- large multicellular and complex parts
- consist of blade, stipe, and holdfast
- photosynthetic
- primarily marine (temperate), usually equipped with some type of float
- alternating generations l
Brown algae (phyopheta)
SAR CLADE
- mostly unicellular (sometimes colonial
- each species uniquely reinforced by cellulose plates
- 2 flagella in grooves between plate (produce swimming movement)
- ecologically important as phytoplankton
- responsible for red tides
Dinoflagellates
ALVEOLATES of SAR CLADE
- malaria causing parasite
* complex lifecycle in multiple host, sexual and asexual
Plasmodium
ALVEOLATES of SAR CLADE
