T2 Classifications and Microbial Growth

Flashcards on Classifications and Microbial Growth based on lecture notes.

Animalia (Kingdom of Animals)

Kingdom that includes organisms that move and get energy from breaking down food through cellular respiration.

Plantae (Kingdom of Plants)

Kingdom that includes organisms that don’t move and use light energy to generate their own food through photosynthesis.

Taxonomy

Science of classification, organizing living organisms into groups based on similarities and differences

Phylogenetics

Tracking evolutionary descent of an animal through studying the genetic material

Robert Hook

Introduced the name “cell” in the 1600s.

Matthias Schleiden

Stated that all plants are made of cells in the 1830s.

Theodor Schwann

Stated that all animals are made of cells in the 1830s

Rudolf Virchow’s Cell Theory

Cell is the basic unit of all organisms. All living things are made of cells. All cells come from pre-existing cells.

Kingdom Protista

Single celled organisms that didn’t fit easily into plant or animal kingdoms were then grouped into this kingdom in 1866.

Kingdom Fungi

Macroscopic or microscopic. Decomposers: break down dead plants and animals to recycle nutrients. Different from photosynthesis (plants) and ingestion (animals)

Prokaryotic

“before nucleus”

Eukaryotic

“true nucleus”

Archaea

Organize their DNA or RNA (ribosomes) in different ways. Are more similar to eukaryotic cells. Plasma membrane has different lipids (ether-linked) from bacteria and eukaryotes (ester linked)

Domain Bacteria

Prokaryotes with peptidoglycans in their cell walls

Domain Archaea

Prokaryotes who often live in extreme environments without peptidoglycans in their cell walls

Domain Eukarya

DNA is in a compartment called nucleus

Domain Archaea

First identified in extreme environments but now know that they live in diverse habitats: soil, water, in organisms, and extreme environments. Considered to be more related to humans than they are to bacteria! None have currently been found to cause disease

Carl Linnaeus

Father of Taxonomy who introduced a system for organizing, classifying and naming organisms

Binomial Nomenclature

Genus species

Identifying Bacteria

Selective media do not allow some types of bacteria to grow, while allowing rapid growth of another type. Differential media allow one to see visible changes in the media that are associated with a specific type of bacteria.

Staphylococcus aureus

Round bacteria that grow in clusters and form golden colonies on agar plates: “golden grape clusters”

Strain

A subgroup of a species with one or more characteristics that distinguish it from other subgroups of the same species.

Bacterial Growth

Increase in cell NUMBER through cell division

Obligate aerobes

MUST have oxygen to survive

Facultative anaerobes

Can use oxygen if it is there but can also live without

Obligate anaerobes

Prefer to grow without oxygen and May be harmed by oxygen

Aerotolerant anaerobes

Do not use oxygen but can tolerate it

Cultural medium

Has the perfect nutrients, salt level and pH for the microbe you want to grow

Binary Fission

Each bacterial cell makes an exact copy of itself. The time required to perform a division is the generation time. Average generation time is 1-3 hours

Lag Phase

No division, cells are settling into their new environment, lots of metabolic activity as cells get ready to divide

Log Phase

Once cells have enough energy and materials they start rapidly dividing. Growth is logarithmic.

Stationary Phase

Usually the microbes start to exhaust nutrient supply and stop dividing

Death Phase

More cells die than are being made and cells are killed by built up waste products

Diluent

A solution used to dilute the samples (e.g. water, saline, buffer)

Dilution Factor (DF)

The amount of original solution / Total amount of new solution you made