mic203 lec1

Flashcards based on lecture notes about the three domains of life, microbes, and cell characteristics.

What are the three domains of life?

Bacteria, Archaea, and Eukarya

What are microbes (microorganisms)?

Minute living things that individually are usually too small to be seen with the unaided eye, including acellular entities, prokaryotic cells, and eukaryotic cells.

What is the Human Microbiome/Microbiota?

Microbes that live permanently in and on the human body.

How was the discovery of three cell types occurred?

By comparing the nucleotide sequences of ribosomal RNA (rRNA).

Besides rRNA, what are the main differences between the three domains?

Membrane lipid structure, Transfer RNA, and Antibiotic sensitivity.

Which kingdoms are included in the Domain Eukarya?

Fungi, Plantae, Protista, and Animalia.

Which domains are prokaryotic?

Bacteria and Archaea.

What are the characteristics of Archaea's cell type, cell wall, membrane lipids, first amino acid in protein synthesis, antibiotic sensitivity, rRNA loop, and common arm of tRNA?

Varies in composition; contains no peptidoglycan; composed of branched carbon chains attached to glycerol by ether linkage; methionine; no antibiotic sensitivity; lacking rRNA loop; lacking common arm of tRNA.

What are the characteristics of Bacteria's cell type, cell wall, membrane lipids, first amino acid in protein synthesis, antibiotic sensitivity, rRNA loop, and common arm of tRNA?

Contains peptidoglycan; composed of straight carbon chains attached to glycerol by ester linkage; Formylmethionine; Yes antibiotic sensitivity; Present rRNA loop; Present common arm of tRNA.

What are the characteristics of Eukarya's cell type, cell wall, membrane lipids, first amino acid in protein synthesis, antibiotic sensitivity, rRNA loop, and common arm of tRNA?

Varies in composition; contains carbohydrates; composed of straight carbon chains attached to glycerol by ester linkage; Methionine; No antibiotic sensitivity; Lacking rRNA loop; Present common arm of tRNA.

What is Archaea?

Prokaryotic cell without peptidoglycan in the cell wall that thrives in extreme environments and has unusual metabolic processes.

What are the three major groups of Archaea?

Methanogens, Extreme halophiles, and Hyperthermophiles.

What are the five well described phyla of archaeal phylogenetic tree?

Euryarchaeota, Nanoarchaeota, Korarchaeota, Crenarchaeota, Thaumarchaeota

What are bacteria?

Relatively simple, single-celled (unicellular) organisms.

What are the most common shapes of bacteria?

Bacillus (rodlike), Coccus (spherical or ovoid), and Spiral (corkscrew or curved).

What are bacterial cell walls largely composed of?

A carbohydrate and protein complex called peptidoglycan.

How do bacteria reproduce?

Binary fission.

How does bacteria obtain nutrition, food production, movement?

Uses organic chemicals, comes from either dead or living organisms; needs light, water & CO2; moving appendage such as flagella helps to swim; some bacteria can manufacture their own food by photosynthesis, and some can derive nutrition from inorganic substances.

Name all of Bacteria's Phylas.

Proteobacteria, Cyanobacteria, Chlorobi, Chloroflexi, Chlamydiae, Planctomycetes, Bacteroidetes, Fusobacteria, Spirochaetes, Deinococcus-Thermus, Firmicutes, Tenericutes, Actinobacteria

What are Proteobacteria?

Largest taxonomic group of bacteria; most are gram-negative chemoheterotrophs.

What are the five classes of Proteobacteria?

Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, Epsilonproteobacteria

What are Alphaproteobacteria?

Capable of growth at very low levels of nutrients; some have unusual morphology and include agriculturally important bacteria.

What are Rickettsia?

Gram-negative rod-shaped bacteria, or coccobacilli transmitted to humans by bites of insects and ticks and are obligate intracellular parasites.

What does Rhizobium do?

Infects the roots of leguminous plants, leading to the formation of root nodules where they form a symbiotic relationship, fixing atmospheric nitrogen for plant protein.

What is Betaproteobacteria?

Uses unusual nutrient substances, such as hydrogen gas, ammonia, and methane; relatively large, Gram-negative, aerobic organism, motile by helical conventional polar flagella.

What is Gammaproteobacteria?

Facultatively anaerobic rods that are active fermenters of glucose and other carbohydrates; have fimbriae that help them adhere to surfaces or mucous membranes; produce bacteriocins that can kill closely related bacteria; Enterobacteriales are often called enterics.

Describe Enterics.

Possess specialized sex pili for the exchange of genetic information between cells; produce proteins called bacteriocins that can kill closely related bacteria.

What is vibrio?

Rods that are often slightly curved; one important pathogen is Vibrio cholerae, the causative agent of cholera.

What is Deltaproteobacteria?

Distinctive; consists of predator bacteria and contributes to the sulfur cycle; Bdellovibrio attacks other Gram-negative bacteria.

What is Epsilonproteobacteria?

Slender gram-negative rods (helical or curved); Campylobacter are microaerophilic vibrios that include species causing spontaneous abortion in domestic animals and foodborne intestinal disease.

What is Cyanobacteria?

Blue-green (cyan) pigmentation, performs oxygenic photosynthesis, and can fix N2 from the atmosphere inside heterocysts.

How does cyanobacteria move?

Through gas vacuoles or gliding motility.

Where is the general habitat of Purple and green photosynthetic bacteria?

deep sediments of lakes and ponds.

What is Chlamydiae?

Cell wall has no peptidoglycan and has a unique development cycle with infectious Elementary body (metabolically inactive and nonreplicating) and metabolically active and replicating Reticulate body.

Which pathogens are significant for humans?

Three species of the chlamydia (Chlamydia trachomatis, Chlamydophila psittaci, Chlamydophila pneumoniae)

What are Planctomycetes?

Known as “blur the definition of what bacteria are”; Gram-negative & budding bacteria; aquatic bacteria that produce stalks resembling Caulobacter; no peptidoglycan in cell wall; Contains organelles alike Nucleus of eukaryotic; has double membrane around its DNA.

What are Bacteroidetes?

Common members of human microbiome, especially human GI tract; Prevotella found in human mouth; Elizabethkingia is an emerging cause of healthcare-associated infections; include Genera of aerobic and anaerobic bacteria.

What are Fusobacteria?

Genus Fusobacterium are anaerobes and often pleomorphic; long, slender, gram-negative rods with pointed rather than blunt ends; found mostly in the gingival crevice of the gums and may be responsible for some dental abscesses.

What is Spirochetes?

coiled morphology; motility method, uses two or more axial filamentous flagella (endoflagella) - endoflagella is located in the periplasmic space.

What is Firmicutes?

Low G + C Gram-Positive Bacteria; includes endospore forming (Clostridium and Bacillus), medical microbiology (Staphylococcus, Enterococcus, and Streptococcus), and industrial microbiology (Lactobacillus).

What is Tenericutes?

Cell wall less bacteria (Mycoplasmas); pleomorphic because they lack a cell wall; ranging from 0.1 to 0.25 μm; most significant human pathogen is M. pneumoniae, causes of a common form of mild pneumonia.

What is Actinobacteria?

High G+ C containing bacteria; includes Corynebacterium and Gardnerella; pathogenic genera Mycobacterium causes tuberculosis and leprosy; extended branching filamentous (star-like growth) morphology like Streptomyces.

What is Plants?

Multicellular organisms, cells contain chloroplasts and are able to carry out photosynthesis, cells have cellulose cell walls, store carbohydrates as starch or sucrose

What is Eukarya Domain?

Eukaryotes; shows great range of diversity in their shape, size and physiology; unicellular to micro and macro organisms.

What are the six most well known classes of animals?

Mammals, birds, fish, reptiles and amphibians Invertebrates.

When did the first Eukaryotes appear?

The very first eukaryotes, were probably unicellular microbes, [appeared ̴ 2/2.5 billion years ago].

What is the endosymbiotic theory in the evolution of Eukaryotes?

Larger bacterial cells lost their cell walls and engulfed smaller bacterial cells, ancestral eukaryote developed a rudimentary nucleus when the plasma membrane folded around the chromosome.

Explain the endosymbiotic theory of mitochondria and chloroplasts

Mitochondria and chloroplasts may be descendants of photosynthetic prokaryotes ingested by this early nucleoplasm

What are the reasons for the endosymbiotic theory of mitochondria and chloroplasts?

Similarity between bacteria and the mitochondria and chloroplastsShape & size Circular DNAReproduce independentlySize of Ribosome Mechanism of protein synthesisAntibiotic that targets bacterial ribosome also works against mitochondrial & chloroplast ribosome

What are the list of the Domain Eukaryotes?

Unicellular ,Fungi (unicellular yeasts), Protozoans (Trypanosoma, Amoeba, Giardia, Paramecium), Slime molds (Cellular and Plasmodial); Multi-cellular ,Animals (sponges, worms, insects, and vertebrates), Plants (mosses, ferns, conifers, and flowering plants), Fungi (multicellular molds, and mushrooms), Chromista (Algae)

What are the two taxa of slime molds?

Cellular & Plasmodial.

What does Plasmodial slime molds exist as?

A mass of protoplasm (called Plasmodium) and multinucleated.

What is Cytoplasmic streaming mean regarding to Plasmodium?

Cytoplasmic streaming: Plasmodium moves and changes simultaneously its speed and all way direction in order to evenly distribute O2 and nutrient.

How does Protozoa reproduce?

Sexually or asexually

What movements does Protozoa have?

Pseudopods (false feet), flagella and cilia.

What is the major cell wall constituent of Algae?

Cellulose

State the form of shape do Algae have?

There is both unicellular and multicellular Algae

What is the habitat of Mold?

Soil, seawater, freshwater, or an animal or plant host.

What is the habitat for Fungi?

soil, seawater, freshwater, or an animal or plant host.

What is Mold’s visible part mycelia?

aerial hyphae composed of filaments (hyphae) [branched & intertwine].

Explain what is Animals characteristics

chemoheterotrophs; rely on other animal for nourishment; mostly sexually; Adult animals develop from embryo; they can regenerate body parts; Possess digestive system (simple to complex).