Untitled Quiz

• Microorganisms can be acellular or cellular
• Acellular microorganisms include viruses, prions, and viroids
• Cellular microorganisms are divided into eucaryotes and procaryotes

Eucaryotes

• Algae, protozoa, and fungi are eucaryotes

Procaryotes

• Bacteria, cyanobacteria, and archaea are procaryotes

Prokaryote cell structure

• DNA consists of a strand in a nucleoid
• Contains ribosomes
• Cytosol is present
• A plasma membrane exists
• Has a cell wall
• May have a capsule
• Fimbriae can be found
• A plasmid may be present
• Flagellum is seen on some

Eucaryote cell structure (Animal)

• Contains a nucleus
• Cytoplasm is present
• Has a cell membrane
• Contains a nucleolus
• Has endoplasmic reticulum
• Golgi complex is present
• Vacuoles are present
• Lysosomes are observed
• A mitochondrion is present

Eucaryote cell structure (Plant)

• Contains a nucleus
• Cytoplasm is present
• Has a cell membrane
• Cell wall is present
• Contains a nucleolus
• Has endoplasmic reticulum
• Golgi apparatus is present
• Vacuoles are present
• Chloroplast is observed
• A mitochondrion is present
• Has a nuclear envolope

Terms

• Fimbriae are hairlike bristles that foster adhesion to surfaces
• Pilus is an elongated and hollow appendage used to transfer DNA to other cells
• Flagellum is a rotating filament that pushes the cell forward
• Glycocalyx is a gel-like coating outside of the cell wall; it can be either a capsule or a slime layer
• Inclusion bodies store nutrients for later use
• Nucleoid is the location of bacterial chromosomes
• Ribosomes are the sites of protein synthesis
• Plasma membrane surrounds the cytoplasm and regulates the entrance and exit of molecules
• The cell wall provides support and shapes the cell
• Mesosome is the plasma membrane that folds into the cytoplasm

Flagella arrangements

• Monotrichous: A single flagellum
• Amphitrichous: Flagella at both ends of the cell
• Lophotrichous: Multiple flagella at one end of the cell
• Peritrichous: Flagella distributed over the entire cell

Cell wall types

• Gram-positive cell walls retain crystal violet dye and stain dark violet or purple.
• Gram-negative cell walls can be decolorized to accept counterstain (safranin) and stain red.

Gram-Positive Cell Walls

• Thick and multilayered peptidoglycan layer
• Present of teichoic acids
• Absent outer membrane
• Absence of a Periplasmic space
• Very little Lipopolysaccharide (LPS) content
• Lower level of lipid and lipoprotein content
• Has 2 rings in basal body
• Primarily exotoxins
• Resistance to physical disruption is high
• High susceptibility to penicillin and sulfonamide
• Low susceptibility to streptomycin, chloramphenicol, and tetracycline

Gram-Negative Cell Walls

• Thin and single-layered
• absent teichoic acids
• present outer membrane
• presence of a Periplasmic space
• higher Lipopolysaccharide (LPS) content
• Higher level of lipid and lipoprotein content
• Has 4 rings in basal body
• Primarily endotoxins
• Lower resistance to physical disruption
• Lower susceptibility to penicillin and sulfonamide
• High susceptibility to streptomycin, chloramphenicol, and tetracycline

Sporulation

• Spore septum begins to isolate newly replicated DNA along with a small portion of the cytoplasm
• Plasma membrane starts to surround DNA, the cytoplasm and the membrane
• Spore septum surrounds isolated portion, forming forespore
• Peptidoglycan layer forms between the membranes
• A spore coat forms
• Endospore is freed from the cell

Differences Between Prokaryotic and Eukaryotic Cells

• Prokaryotic cells typically range from 0.2 to 2.0 µm in diameter, while Eukaryotic cells range from 10 to 100 µm
• Prokaryotes lack a nuclear membrane or nucleoli, Eukaryotes have a true nucleus and a nuclear membrane and nucleoli
• Prokaryotes lack membrane-enclosed organelles, while Eukaryotes contain them.
• Prokaryotes have flagella consisting of two protein building blocks, while Eukaryotes have a complex flagella with multiple microtubules
• Prokaryotes tend to have a cell wall that is chemically complex, while Eukaryotes have chemically simple walls when present
• Prokaryotes contain Cytoskeleton consisting of protein building, while Eukaryotes lack it
• Prokaryote ribosomes have a smaller size (70S) and are free, while Eukaryote tend to have a larger one(80S) and are in organelles.
• Prokaryotes possess a single, circular chromosome lacking histones, while Eukaryotes contain multiple linear chromosomes with histones
• Prokaryotes reproduce using binary fission, while Eukaryotes mitosis
• Prokaryotes reproduce sexually with the transfer of DNA fragments and Eukaryotes Involves meiosis

Cell division

• Cell elongates and DNA is replicated
• Cell wall and plasma membrane begin to divide
• Cross-wall forms completely around divided DNA
• Cells separate

Binary Fission Steps

• Cell replicates its DNA
• Membrane elongates, separating DNA molecules
• Cross wall forms; membrane invaginates
• Cross wall is completed
• Daughter cells form