Ch.3 Micro Objectives
Describe endoflagella
flagella at both ends that spiral tightly around the cell
Describe cytoplasm
gelatinous material inside the cell composed of cytosol, inclusions, ribosomes, and a cytoskeleton
What is the function of chloroplast?
light harvesting structures found in photosythetic eukaryotes
What is the structure of bacterial flagella?
long structures that extend beyond the surface of a cell and its glycocalyx
Explain the fluid mosaic model of membrane structure
membrane proteins are arranged in a way that resembles the tiles in a mosaic, the proteins and lipids are free to flow laterally within a membrane
What is the evidence of endosymbiotic theory?
mitochondria and chloroplasts divide independently of the cell but remain dependent on the cell for most of their proteins.
What is the structure and function of ribosomes?
nonmembranous organelles, composed of 60S and 40S subunits, attached to the membranes of the endoplasmic reticulum
What is the function of archael fimbriae?
nonmotile, rodlike, sticky projections that anchor the cells to one another and to environmental surfaces
Name the membranous organelles
nucleus, ER, golgi body, lysosome, peroxisome, vesicle, vacuole, mitochondria, and chloroplast
Describe Group translocation
occurs only in some bacteria, the substance that is being transported is chemically changed during transport; active process that requires energy
Describe Osmosis
passive; diffusion of water across a selectively permeable membrane
Describe facilitated diffusion
passive;proteins facilitate the movement of certain molecules down their concentration gradient.
What is the function of mitochondria?
powerhouses of the cell because they produce ATP
What is the difference between prokaryotes and eukaryotes
presence of numerous membranous organelles in eukaryotes
What is an inclusion?
reserve deposits of lipids, starch, or compounds containing nitrogen, phosphate, or sulfur
Name the nonmembranous organelles
ribosomes, cytoskeleton, and centrioles
What is the function of the Golgi body?
shipping department; recieves, processes, and packages large molecules for export
What is the structure and function of ribosomes?
sites of protein synthesis. composed of two subunits
What is the structure and function of fimbriae?
sticky, bristlelike projections to adhere to one another and to substances in the environment
What is the function of a lysosome, peroxisome, vacuoles, and vesicles?
store and transfer chemicals within eukaryotic cells
Describe Active Transport
substances transported through gated channels; requires energy
Describe the endosymbiotic theory
suggest that eukaryotes formed from the union of small aerobic prokaryotes with larger anaerobic prokaryotes
Describe the role of pseudopodia in eukaryotic cells
surround the substance and bring it into the cell
What is the function of the nucleus?
the control center of the cell, contains most of the cells genetic instructions in the form of DNA
What is the function of bacterial flagella?
to propel the cell though its environment
What is the function of the ER?
transport system and is found in smooth ER and rough ER. SER=lipid synthesis; RER=protein sythesis
What are the three filaments of a eukaryotic cytoskeleton?
tubulin microtubules, actin, and intermediate filaments
List 4 bacterial flagellar arrangements
1. Peritrichous 2. Polar 3. endoflagella 4. lophotrichous
Compare and contrast archael flagella with bacterial flagella
Archael flagella are about half the diameter, lack a central channel, share common amino acid sequences through the species, powered by ATP, rotate together in both directions
Describe the structure of archael glycocalyces
Archael- gelatinous, sticky, composed of polysaccharides, polypeptides or both; none shown to be pathogenic
compare and contrast the cell walls of acid-fast bacteria with typical gram+ cell walls
Both are gram +. Acid fast techniques are for cells with a thick layer of waxy lipids.
Contrast the cytoplasm of archea with bacteria
Both have 70S ribosomes, a fibrous cytoskeleton, and circular DNA suspended in a liquid cytosol, no membranous organelles
Distinguish between capsules and slime layers
Capsules are firmly attached to the cell surface (boston baked bean) Slime layer is loose and water-soluble (Goobers)
What are the common shapes of bacteria?
Cocci (single sphere), streptococci (clusters of spheres), bacilli (rod shaped)
Describe the function of eukaryotic glycocalyces
Function as an anchor to animal cells, provides protection from dehydration
Contrast exocytosis and endocytosis
Endocytosis brings materials into the cell while exocytosis pushes materials out of the cell, soley eukaryotic
Describe the clinical application of a gram - cell wall
Gram - cells contain lipid A. Lipid A releases endotoxin on death that causes fever, vasodilation, inflammation, shock and blood clotting
Compare and Contrast walls of Gram-+ and Gram - cells
Gram+ cells have a thick wall above the membrane. Gram- cells only have a cell membrane
What are the four major processes of living cells?
Growth, Reproduction, Responsiveness, and Metabolism
Distinguish between Isotonic, Hypertonic, and Hypotonic
Isotonic is when a substance is equally distributed. Hyptertonic is when the substance is in a higher concentration (food coloring in the dropper). Hypotonic is when the solution has a lower concentration of the solution (water in the bowl has one drop of food coloring that has dissolved)
What is the structure and function of pili?
Longer than fimbriae and usually shorter than flagella, typically one, transfers DNA for reproduction
Describe Diffusion
Passive; the net movement of chemical down its concentration gradient; requires no energy output
Describe Polar Flagella
Polar=monotrichous One flagella on one end
Compare and Contrast prokaryotic and eukaryotic cells.
Prokaryotes do not have a nucleus or organelles. Eukaryotes have a nucleus and compartmentalized organelles
What is the function of a glycocalyces?
Protect the cell from desication, adhesion to surfaces, prevent bacteria from being recognized or devoured by defensive cells of host
What are hami?
Unique proteinaceous, fimbriae-like structures; more than 100 radiate from the surface, look like grappling hooks and function to securely attach archaea to biological and inanimate surfaces
Describe lophotrichous
a tuft of polar flagella
What is an Endospore and what is its importance?
a vegetative cell that is lacking one or more nutrients. defensive strategy against hostile or unfavorable conditions. resistant to drying, heat, radiation, and lethal chemicals
What is the structure and function of centrioles?
animal and some fungi contain two centrioles which lie at right angels to the nucleus, play a rolein mitosis and the formation of flagella and cilia
Contrast the archael cytoplasmic membrane with bacteria
both types of membranes maintain electrical and chemical gradients in the cell, controls the import and export of substances
Compare and Contrast eukaryotic cilia and flagella
cells have hundredes of Cilia to propel itself, flagella have few projections
What is the structure and function of cytoskeletons?
composed of an internal network of fibers and tubules; acts to anchor organelles and functions in cytoplasmic streaming and in movement of organelles within the cytosol
What is the composition of a glycocalyces?
composed of polysaccharides, polypeptides or both
Describe carchael cell walls
composed of specialized proteins or polysaccharides, coats the cell like chain mail; LACK peptidoglycan. Stain like bacteria when gram+ or gram -
Describe the sugar and peptide portions of peptidoglycan
composed of two types of regularly alternating sugar molecules called NAG and NAM
Describe the structure and function of cilia
composed primarily of tubulin microtubules; no prokaryotic cells have cilia; propels single celled eukaryotes or move substances in the local environment
Describe the structure and formation of archael flagella
consists of a basal body, hook, and filament each composed of protein; rotates like a propeller
What is the structure and function of cytoskeleton?
contain internal network of fibers, role in forming a cell's basic shape
Describe the functions of a cytoplasmic membrane
controls the passage of substances into and out of the cell, functions in producing molecules for energy storage and for harvesting light
Describe Peritrichous flagella
covers the surface of the cell
Compare and contrast the structure and function of prokaryotic and eukaryotic flagella
eukaryotic flagella are within the cytoplasmic membrane and the shaft is composed of molecules of a globular protein called tubulin; don't rotate like prokaryotic flagella, they undulate rhythmically