BIOL 2460 CHAPTER 3

spontaneous generation

Hypothesis stating that life could arise from nonliving matter by Aristotle

Francesco Redi

This scientist disproved spontaneous generation by showing that maggots do not spontaneously arise from decaying meat.

John Needham

Heated broth in sealed flasks. When the broth became cloudy with microorganisms, he mistakenly concluded that they developed spontaneously from the broth. He did not boil the broth long enough and thus believed that life must originate from "life force".

Lazzaro Spallanzani

Replicated Needham's experiment correctly and showed that a sealed flask of meat broth sterilized by boiling failed to grow microbes

Louis Pasteur

-Disproved spontaneous generation with swan-neck flasks that blocked airborne microorganisms.

-Organisms could spoil food and, therefore, people.

Robert Hooke

First to observe "small chambers" in cork and call them cells.

Matthias Schleiden

All plants are made of cells

Theodor Schwann

all animals are made of cells

Robert Remak

All cells come from pre-existing cells (cell division). Originally came up with this idea, but later had it stolen by Virchow.

Rudolf Virchow

All cells come from other cells

endosymbiotic theory

mitochondria and chloroplasts arose as a result of prokaryotic cells establishing a symbiotic relationship within a eukaryotic host

Konstantin Mereschkowski

chloroplasts could reproduce independently and must have lived outside plant cell

Ivan Wallin

showed mitochondria outside of cell (but likely contamination)

Lynn Margulis

Developed the Endosymbiotic Theory. Mitochondria and chloroplasts of prokaryotic origin established a symbiotic relationship with a eukaryotic host.

Germ Theory of Disease

idea that infectious diseases are caused by microorganisms

Girolamo Fracastoro

"spores" can be transferred between individuals

Ignaz Semmelweis

advocated hand washing to prevent transmission of puerperal fever from one OB patient to another. Believed that contaminated physicians transferred causative agent to patients.

John Snow

Mapped the occurrence of cholera in London via water

Joseph Lister

Began using disinfectants and antiseptics during surgery. Handwashing + carbolic acid in surgery for

disinfection

Prokaryote

-unicellular organism that lacks a nucleus

-circular chromosome in nucleioid

-Domains: Bacteria, Archaea

Eukaryote

An organism whose cells contain a nucleus surrounded by a nuclear membrane that contains several chromosomes.

-Domain: Eukarya

-coccus (pl. -cocci)

berry-shaped

Bacillus

Rod shaped bacteria

Vibrio

curved rod

Coccobaccilus

short rod

Spirillum

spiral shaped bacteria

Spirochetes

long, loose, helical spiral

Crenation

shrinking of red blood cells. Occurs in a hypertonic solution of a cell without a cell wall

Plasmolysis

Happens in a hypertonic solution of a cell with a cell wall. Plasma membrane pulls away from cell wall, allowing cell to maintain some shape and integrity

Prokaryotic Chromosomes are

haploid

nucleoid-associated proteins (NAPs)

-a set of DNA-binding proteins found in bacteria that facilitate chromosome compaction and organization

-similar to histones

Plasmids

-Extrachromosomal ring of accessory DNA in the cytoplasm of prokaryotes.

-confer advantageous traits like antibiotic resistance

70s ribosomes

smaller ribosomes found in prokaryotes

50s and 30s

Inclusions

-stores excess nutrients

-reduce the buildup of osmotic pressure when gaining

Volutin (metachromatic granules)

inclusions that store polymerized inorganic phosphate that can be used in metabolism and assist in the formation of biofilms.

sulfur granules

Inclusion that stores elemental sulfur for metabolism in bacteria

Polyhydroxy butyrate (PHB)

Inclusion that is surrounded by a phospholipid monolayer embedded with protein

gas vacuoles (inclusions)

alters buoyancy so prokaryotic cells can adjust location in water column

Magnetosomes (Inclusion)

-inclusions of magnetic iron oxide or iron sulfide surrounded by a lipid layer

-allow cells to align along a magnetic field, aiding their movement

carboxysomes (inclusion)

-composed of outer shells of thousands of protein subunits

-RuBisCO and carbonic anhydrase for carbon

metabolism

Endospore

allow some bacterial cells to survive long periods without food or water and in extreme environments. Structure formed in a dormant state to protect the genome.

Sporylation

process of forming an endospore

-DNA replicates

-membrane forms around dna

-forespore forms more membranes

-protective cortex forms around spore

-protein coat forms around cortex

-spore is released

germination

endospore returns to vegetative state

Archael Membranes

-formed with ether linkages

-branched chains

-sometimes lipid monolayered

peptidoglycan

Cell wall of bacteria

Glycocalyx

A sugar coat that allows cells to adhere to surfaces, protects against desiccation, antibiotics, and or disinfectants

-capsules and slime layer

capsule

organized layer located outside of the cell wall and usually composed of polysaccharides or proteins

slime layer

-a less tightly organized layer that is only loosely attached to the cell wall and can be more easily washed off

-made of polysaccharides, glycoproteins or glycolipids

Glycocalyces

-Function in the formation of biofilms

-Adhere cells to one another and inanimate objects

Biofilm

A surface-coating colony of one or more species of prokaryotes that engage in metabolic cooperation.

S-layer

An outermost cell surface layer composed of protein or glycoprotein present on some Bacteria and Archaea. Thought to help with ridgetness and against osmotic pressure

Fimbriae

-short bristle-like proteins projecting from the cell surface by the hundreds

-enable a cell to attach to surfaces and to other cells

pilli

-less numerous protein appendages that aid in attachment to surfaces or transfer of DNA

F pilus (sex pilus)

important in the transfer of DNA between bacterial cells

basal body

motor for the flagellum and is embedded in the plasma membrane

monotrichous flagella

one flagella

Amphitrichous

flagella at both poles of the cell

Lophotrichous

cluster of flagella at one or both ends

Peritrichous

flagella all over

tumbling

clockwise rotation of flagella to reorient cells

running

counter clowise rotation of flagella to move forward

coenocyte

cells who nuclei divide but whose cytoplasm does not.

Stroma

fluid portion of the chloroplast; outside of the thylakoids

Thylakoid

A flattened membrane sac inside the chloroplast, used to convert light energy into chemical energy.

Plasma Membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Cell wall

strong, supporting layer around the cell membrane in some cells

osmosis

-gram positive = thicker cell wall

-Gram-negative = thinner cell wall

Passive transport

The movement of materials through a cell membrane without using energy

facilitated diffusion

Carrier proteins that ferry larger molecules across w/o ATP

Active Transport

membrane proteins that move molecules with ATP

group translocation

a special form of active transport that occurs exclusively in prokaryotes, the substance is chemically altered during transport across the membrane.

Cyanobacteria

Bacteria that can carry out photosynthesis with thyalcoids

Photosynthetic bacteria

chromatophores, lamellae, or chlorosomes

Ribosomes (in eukaryotes)

80S (40S small subunit + 60S large subunit) in chloroplast and mitochondria

Rough Endoplasmic Reticulum

Makes and transports proteins (ribosomes)

Smooth Endoplasmic Reticulum

no ribosomes and synthesizes lipids, metabolizes carbs, and detoxifies compounds

Robert Koch

Koch's postulates - a specific microbe can cause a specific disease

Cell membrane

A cell structure that controls which substances can enter or leave the cell.

-Archaea: Ether linkages

-Bacteria and Eukaryotes: Ester linkages

Gram negative

-Lipopolysaccharide (LPS) structure

-Contributes to fever, shock, &hemorrhaging

-E. coli O157:H7 strain has a different O-antigen (jack in the box)

Pseudopeptidoglycan

A component of (a few) archaea cell walls that is similar to peptidoglycan in morphology but contains different sugars

Basic flagella structures

basal body, hook, filament

Nucleus in eukaryotes

DNA material is surrounded by a membrane. Chromosomes are linear

Nucleolus

Dense region in the nucleus where ribosomal RNA (rRNA) is synthesised

Golgi apparatus (eukaryotes)

A system of membranes that modifies and packages proteins for export by the cell

-membranous disks(dictyosomes) stacked together

-Vesicles carry modified molecules to other parts of

the cell

Lysosomes

An organelle containing digestive enzymes. Breaks down food, damaged organelles, or cellular debris

Peroxisomes

Not part of the endomembrane system. Membrane-bound organelles that produce hydrogen peroxide. Contribute to lipid synthesis as well as the degradation of molecules.

Cytoskeleton in eukaryotes

Filaments inside the cell that provide structure and network for transport

-Microfilaments

-Intermediate filaments

-Microtubules

Microfilaments

intertwining actin fibers that have contraction-like movement

-Allows organisms such as amoebaslocomotion

Pseudopodia

temporary extensions ofmembrane that fill with microfilaments

Intermediate filaments

monomers that are thinner than microtubules but thicker than actin. Anchor nucleus and other organelles, and form

nuclear lamina

Microtubules

A hollow rod composed of tubulin proteins that moves vesicles around the cell, supports the cytoskeleton, functions in flagella & cilia, and cell division (centrosomes)

Mitochondria

sites for aerobic respiration, "power house" of the cell

Flagella

A long, whip-like filament that helps in cell motility. Made of microtubules in 9+2 fashion

Cilia

The hairlike projections on the outside of cells that move in a wavelike manner. Also, move particles away from the cell