Bio Test 2: Microbio Flashcards
Characteristics of bacteria. All bacteria are
single celled, prokaryotic (lack nuclues and membrane-bound organnelles), reproduce asexually (binary fission), contain DNA made of a single chromosne
Nitrogen fixation
N2 some bacteria take nitrogen directly from the air to make proteins. These bacteria usually live in nodules on roots of legumes. They cna’t use N2 so they make it into usable gasses
Carbon-oxygen cycle
Bacteria are key in the breakdown of dead organisms and the cycling of carbon dioxide back into the atmosphere. Decompose dead organisms=release stored O2 into atmosphere
Production of vitamin K and B12
occurs in humans in the large intestine, eat your waste to create needed vitamins
Size of a bacteria
1 to 10 upm (1000 upm = 1mm)
DNA in a bacteria is not
enclosed in a nucleolus, chromosne lose in cytoplasm
Flagellum
whip-like movement not always present
Plasmid
loop of DNA which is exchanged during conjugation
Cytoplasm in bacteria
contains ribosomes for protein synthesis, factory to make proteins
Capsule in bacteria
reduces water loss, resists high temperatures and protects against antibiotics and viruses, don’t need it but useful
Cocci
round
Bacilli
Rod-shaped
Spirilli
spiral
Staphylo
clusters
Strepto
chains
Diplo
pairs
Mono
individual cells
Naming bacteria
group then shape, can be any combo
Gram-Positive
stained purple after a dyeing technique with crystal violet and iodine, these bacteria have a thick cell wall and are mostly harmless. Strepto coccus
Gram-negative
stained pink these bacteria have a thin cell wall and many are pathogenic, can make you sick but not always. Salmonella
heterotrophic
must eat others for food
autotrophic
able to mkae own food (photoautrophic-sunlight) (chemoautotrophic-chemicals)
Aerobic (Aerobes)
use oxygen to produce energy from food, obligate (need oxygen to survive) or facultative (can switch dependancy on oxygen)
Anaerobic
do not require oxygen to produce energy, can be obligate (will die if exposed to o2)