Chapter 27 Flashcards
What are the 3 domains of life?
Bacteria
Archaea
Eukarya
What are the differences between Prokaryotes and Eukaryotes?
Eukaryotes are larger, more complex
they can be multicellular unlike prokaryotes
Eukaryotes have a nucleus and membrane bound organelles while prokaryotes have a nucleoid and no internal membranes
What domains do prokaryotes occupy?
Bacteria and Archaea
What are the three common shapes of bacteria?
Spheres; cocci- staphylococcus
rods; bacilli- lactobacillus
curves/spirals; vibrios, spirilla, spirochettes- vibrio cholerae
What are flagella?
A long cellular appendage specialized for locomotion
What are fimbriae?
A short, hairlike appendage of a prokaryotic cell that helps it adhere to the substrate or to other cells
What is a cell wall?
maintains shape and provides protection
What is lysis?
the disintegration of a cell by rupture of the cell wall or membrane.
What is a gram stain? Gram positive? Gram negative?
a staining technique for the preliminary identification of bacteria, in which a violet dye is applied, followed by a decolorizing agent and then a red dye. The cell walls of certain bacteria (denoted Gram-positive ) retain the first dye and appear violet, while those that lose it (denoted Gram-negative ) appear red
What is peptidoglycan?
Peptidoglycan, also known as murein, is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of most bacteria, forming the cell wall
What are antibiotics?
Antibiotics or antibacterials are a type of antimicrobial used in the treatment and prevention of bacterial infection. They may either kill or inhibit the growth of bacteria
What is a capsule?
a gelatinous layer forming the outer surface of some bacterial cells.
What is a slime layer?
A slime layer in bacteria is an easily removable (e.g. by centrifugation), unorganized layer of extracellular material that surrounds bacteria cells.
What is biofilm?
A thin, slimy film of bacteria that forms. It can communicate by sending out signals that attract more bacteria, thus growing.
What are attachment pili?
fimbrae
What is taxis?
movement away from or towards stimulus.
positive taxis is towards stimulus and negative taxis is away from stimulus
What is chemotaxis?
A chemical stimulant is used
What is phototaxis?
A light stimulant is used
What is the circular ring of DNA in prokaryotes?
not surrounded by a nuclear membrane, located in a nucleoid region, fewer proteins associated with DNA, haploid
What are some examples of specialized membranes performing metabolic functions in prokaryotes?
cellular respiration
photosynthesis
What are plasmids?
Small rings of independently replicating DNA, provides antibiotic resistance in some R plasmids, can be transferred by conjugation
What are endospores?
Resistant, multilayered cells produced under adverse conditions like nutrient limitations or drought
What is binary fission?
During binary fission, the DNA molecule divides and forms two DNA molecules. Each molecule moves towards the opposite side of the bacterium. At the same time, the cell membrane divides to form 2 daughter cells (asexual)
What are the two types of autotroph?
photoautotrophs- use light as energy, use CO2 as carbon source (photosynthetic prokaryotes)
chemoautotrophs- use inorganic chemicals as energy, use CO2 as carbon source (unique to certain prokaryotes)
