Week One

True or False? All cyanobacteria are blue-green

False

True or False? Gram negative bacteria appear purple after they have been exposed to a Gram stain.

False

List four groups in the domain Eukarya and give an example of each

1) Animalia - beaver. 2) Plantae - oak tree. 3) Protist - Algae 4) Fungi - mushroom

Binary Fission

Asexual reproduction in which a cell's DNA replicates and the cell pinches in half with mitosis.

Unicellularism in Prokaryotes and Eukaryotes

All prokaryotes are single-celled even though some may chain together

List four differences between prokaryotic and eukaryotic cells

All prokaryotic cells are unicellular and eukaryotic are unicellular or multicellular. Prokaryotic DNA exists as a single circle and eukaryotic DNA is in multiple chromosomes. Prokaryotic cells divide by binary fission and eukaryotic cells divide by mitosis. Prokaryotes do not have membrane-bound organelles and eukaryotes do. Prokaryotic cells are smaller than eukaryotic cells.

3 Different Domains Of Organisms

Archaea, Bacteria, Eukarya

Eukarya

Include kingdoms Plantae, Fungi, Animalia and the polyphyletic protists

3 Shapes of bacteria cell walls

Bacillus (rod-shaped) Coccus (spherical) Spirillum (spiral)

Internal Compartamentalization in Prokaryotes and Eukaryotes

Bacterial cells contain no internal compartments or membrane systems or nucleus unlike eukaryotic cells

Clostridium Botulinum

Can grow in food products and produces a toxin that is the most toxic substance in the world. Requires to grow in anaerobic environments so isn't very common. Results from botched preserves.

Prokaryotes

Cells lacking membrane bound organelles

Eukaryotes

Cells with membrane-bound organelles

Decomposers

Creatures that feed on dead organic matter and release their nutrients.

Archaea

Includes Kingdom Archaebacteria which are all bacteria. These are often limited to extreme environments.

Kingdom Bacteria

Distributed more widely than any other group of organisms. Have three distinct shapes. Mostly heterotrophic and are decomposers. Some are autotrophic. Most species of these are not culturable in vitro. Reproduce asexually via binary fission. Some are pathogens but most are harmless.

The bacterium that causes the disease botulism can survive in an anaerobic conditions by forming thick walled resistant ______

Endospores

The three domains of life are

Eukarya, Bacteria, Archaea

Many Archaebacteria are ______ organisms that can live in extremely acidic, salty, hot or anaerobic conditions.

Extremophiles

Grame Negative Bacteria

Have a much thinner cell wall that does not retain the purple dye. Safranin is used to counterstain these cells with a red color to contrast to the purple cells.

Gram Positive Bacteria

Have a thick cell wall that retains a purple dye

Is John Black a heterotroph or an autotroph?

Heterotroph

Most Bacteria are _______ meaning that they derive their energy from organic molecules made by other organisms

Heterotrophic

Cyanobacteria

Major group of photosynthetic bacteria that grow in many environments. Photosynthetic whose pigments include chlorophyll a and the accessory pigments phycocyanin (blue) and phycoerythrin(red). Reproduce by fission and are often surrounded by jellylike sheath. Since they are prokaryotes, they are not related to other algae which are all eukaryotic. These often cause the disagreeable tastes and colors in waters.

Cell Size in Prokaryotes and Eukaryotes

Most bacterial cells are only about 1 micrometer in size whereas most eukaryotic cells are 10 times that size

Kingdom Archaebacteria

Oldest form of life on Earth. Bacteria and Eukarya probably diverged from this. Significantly different form the prokaryotes of kingdom Bacteria. Most of these are extremophiles .

Sensitivity Plate

Petri dish of solid medium that has been uniformly coated on its entire surface with a known bacterium or an unknown sample from an infected patient. Four to eight small paper disks each soaked in a different antibiotic are placed equidistant from each other on the culture surface. After 24 hours an effective antibiotic will produce a halo of clear surface around the disks, a zone of inhibition, where it stopped the growth of bacteria.

Bacteria

Prokaryotes and the most abundant organisms on Earth

Cell Division in Prokaryotes and Eukaryotes

Prokaryotic cells divide by binary fission. The cells pinch in two and the DNA replicates. In eukaryotes, microtubules pull chromosomes to opposite poles during the cell division process in mitosis.

Flagella

Prokaryotic flagella are simple single protein fiber that spins like a propeller. Flagella in eukaryotes are complex that whip back and forth instead of rotating.

What are the three common shapes of bacteria in Kingdom bacteria?

Rod-shaped, spherical, spiral

A ______ is used to determine the effectiveness of one or more antibiotics by comparing bacterial growth or inhibition around paper disks containing various antibiotics

Sensitivyt plate

What is binary fission?

The asexual reproduction of prokaryotes in which a cell's DNA replicates and the cell pinches in half without the nuclear and chromosomal events associated with mitosis.

What is nitrogen fixation?

The transformation of atmospheric nitrogen into other nitrogenous compounds by certain bacteria and cyanobacteria. These compounds can then be used as nutrients by the plant

Endospores

Thick-walled spore like things that surround the chromosome of the bacteria and a small portion of the surrounding cytoplasm. This allows the bacteria to germinate and grow after decades or centuries of inactivity. They are like a stripped down reproducing capable form of the bacteria sealed in. usually occur in gram positive bacteria.

In a Gram stain, why do you counterstain with safranin?

To stain the Gram-negative bacteria red so they contrast with the purple Gram-positive cells

Most bacteria are harmless to humans. True or False?

True!

True or False? Bacteria in kingdom Bacteria are the most abundant and distributed organisms on Earth

True!