Week 2 Prokaryotes

Prokaryote

Single celled organisms that lack intracellular membrane structures, such as nuclei

Archaea

One of the three domains of life, characterized by single-celled prokaryote organisms that are commonly found in extreme habitats (extremophiles) and reproduce asexually

Bacteria

One of the three domains of life, characterized by single celled prokaryote organisms that are extremely ubiquitous and diverse and reproduce asexually; very common (much more than the other domain of this unit)

Aseptic technique

Procedure that’s performed under sterile conditions, usually to avoid bacterial contamination

Peptidoglycan

A polymer consisting of sugars and amino acids that’s an important component of the cell walls of most bacteria

Bacterial colony

A visible cluster of bacteria growing on the surface of or within a solid medium, theoretically cultured from a single cell

Extremophile

An organism that occurs primarily in extreme habitats

Pathogenic

The tendency for an organism that cause disease in its host

Cyanobacteria

Phylum of bacteria that obtains energy via photosynthesis

Protobionts

The term used to describe the first non-living structures that evolved into living cells

Protobionts

____ are thought to be the first single-celled organisms

RNA

A protobiont’s ____ is speculated to be its genetic material

Coacervates

Organized cluster droplets of proteins and carbohydrates; suggested as one possible form of early protobionts

Eukarya, bacteria, archaea

Name the three domains of life

Pathogenic

____ bacteria is disease-causing, but it only makes up a small portion of bacteria species

Nitrogen-fixing bacteria

Genus Rhizobium which are found associated with plant roots and are able to convert atmospheric nitrogen into other forms that can be used by plants as fertilizers

Nodules, legume

Nitrogen-fixing bacteria is located within the ____ on the roots of plants, particularly those plants within the ____ family

Cyanobacteria

____ provide a large proportion of the oxygen in the atmosphere, serving as important primary producers in natural ecosystems

Spherical

What shape is coccus bacteria?

Comma-shaped

What shape is vibrio bacteria?

Rod-shaped

What shape is bacillus bacteria?

Spiral-shaped

What shape is spirochaete?

Eukaryotic cell>bacterial cell>virus>protein

Put the following in order of decreasing size: bacterial cell, virus, eukaryotic cell, protein

Conjugation

Bacterial pilli is responsible for what?

Ribosomes

Both eukaryotic and prokaryotic cells have what organelle?

Gram stain

Differential staining technique used to determine the nature of the cell wall

Gram negative

Type of bacteria with a thin peptidoglycan layer and an outer membrane

Gram positive

Type of bacteria that has a thick peptidoglycan layer and no outer membrane

Endospores

Enable bacteria to germinate after exposure to harsh conditions; not present in all bacteria

Prokaryotes

Most abundant organisms on earth in this domain (live in every environment, even extremes); encompass bacteria and archaea

Phlyogenetically, metabolically

Prokaryotes are ____ and ____ diverse

extremophiles

Many Archaea are ____

gut

Archaeans are an important part of humans’ ____ biota

Cyanobacteria

Type of bacteria that produce oxygen via photosynthesis and fix carbon dioxide and nitrogen out of the atmosphere; food source for invertebrates

Anabaena

Type of cyanobacteria that forms filamentous chains and has akinetes and heterocysts

Heterocysts

Formed during periods of nitrogen limitation in Anabaena; performs nitrogen fixation

Akinetes

Dormant cells in Anabaena that are much tougher than normal vegetative cells (resistant to cold and to drying out)

winter

Akinetes help Anabaena survive during what season?

Oscillatoria

Filamentous cyanobacteria that has oscillating motion as colonies slide back and forth against each other to orient to light sources

Merismopedia

Type of cyanobacteria that forms grid-like sheets as a result of cell division in only two directions

mucilaginous

The colonies of Merismopedia are held together by a ____ sheath