Term
| prokaryotic cell structure |
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Definition
glycocalyx
- capsule (slime layer): layer of gelatinous material covering the cell.
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- composition varies with species: polypeptides, polysaccharides, glycoprotein |
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Term
| function of glycocalyx (capsule or slime layer) |
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Definition
- ahesion to surfaces
- osmotic barriers (protection from pressure)
- protect bacteria from phagocytosis
- storage of nutrient |
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Term
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Definition
- pro = before karyon = kernel
- kingdom monera
- no true nucleus
- genetic material is in "nucleiod" region
- no membrane bound organelles |
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Term
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Definition
fx. locomotion/motility
- peritrichous (all around)
- amphitrichous (both ends)
- monotrichous (one end)
- lophotrichous (a group, but going at one end) |
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Term
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Definition
| - small hair-like projection |
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Term
| function of fimbrae and pili |
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Definition
-sexual conjugation - pili form tubes for transfer of genetic material
- surface adhesion
-bacteriophage receptors - some viruses attach to pili
- NOT involved in motility |
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Term
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Definition
- maintains shape of the cell
- physical protection
- enables the cell to escape rupture (lysis) in a hypotonic environment
- lattice/net-like structure
- consists of peptidoglycan units that repeat over and over |
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Term
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Definition
- many layers of peptidoglycan
- forms a thick rigid structure
- contains techoic acid |
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Term
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Definition
-thin layer of peptidoglycan
- looser lattice (less rigid cell wall)
- high lipid content
- no teichoic acid (largely lipid) |
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Term
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Definition
- regulates diffusion in and out of cell
- contains active transport system
- site of enzymes involved in ATP production |
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Term
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Definition
- phospholipid bilayer
- a "dynamic" arrangement of phospholipids and proteins |
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Term
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Definition
- contains chlorophyll
- only found in photosynthetic bacteria |
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Term
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Definition
- 1 chromosome (DNA) loose in the cytoplasm in the nucleoid region
- bacteria often contain small circular, double-stranded DNA molecules called plasmids. |
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Term
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Definition
- granules scattered throughout the cytoplasm
- protein synthesis, not membrane bound, organelle in both pro. and euk.
- protein synthesis = assemble a.a. into polypeptides |
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Term
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Definition
-accumulated stored materials, valuable stored materials
-metachromatic granules (volutin) stored form of phosphate. primary in gram negative. take up stain more readily (suck up stain fast)
- polysaccharide granules
- lipid inclusions |
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Term
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Definition
-inclusions of iron oxide
- act like magnets
- may protect cells from accumulation of hydrogen peroxide |
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Term
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Definition
-highly resistant stucture
- produced by certain bacteria
- all members of the family Bacillaceae produce endospores
- e.g. Genus Bacillus and Clostridium
- Resistance : the most resistant of all living cells
- highly resistant to: dessication (drying out), heat and toxic chemicals
- low metabolic activity (dormant)
- low water content
- thick spore coat
- heat resistant chemicals (calcium and dipicolinic acid)
- formation of endospores: not a reproductive process
- vegetative cell forms a single spore
- germinates to form one vegetative cell |
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Term
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Definition
- eu - true or good, karyon = kernel
- kingdoms: protista, plantae, fungi, animalia
- true nucleus containing genetic material
- contain membrane bound organelles |
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Term
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Definition
| -network of fibers that form a dynamic framework for support and movement |
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Term
| microfilaments, actin filaments, intermediate filaments |
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Definition
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Term
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Definition
| - form: cilia, flagella, and centrioles |
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Term
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Definition
- specialized structures that perform specific functions
- sequester reactions
- many contain folded membranes (increased surface area) |
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Term
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Definition
| spherical or oval, contains DNA |
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Term
| nuclear envelope/membrane |
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Definition
- double membrane perforated by pores
- maintains nuclear shape and regulates transport in and out of the nucleus |
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Term
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Definition
- one or more spherical bodies within the nuclear envelope
- functions in the synthesis of ribosomal RNA |
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Term
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Definition
- studded with ribosomes
- site for synthesis of secretory proteins and membrane molecules |
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Term
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Definition
- lack ribosomes
- synthesizes phospholipids, fats, and steroids |
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Term
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Definition
- formed of 2 subunits: 60S and 40S
- free ribosomes:suspended in the cytoplasm
- bound ribosomes: attached to ER
- sites of protein synthesis |
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Term
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Definition
- flattened sacs, stacked on one another (pancakes)
- receive and modify products from the ER
- packages products in vesicles that transport, secretory, and storage
- lysosomes: membrane-enclosed sac of hydrolytic enzymes
- functions in phagocytosis, recycling cells own organic material
- programmed cell destruction |
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Term
| lysosomal storage disease |
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Definition
- lysosomes lack one of the hydrolytic enzynmes
- i.e. Tay-Sachs diseas: lack enzyme to digest lipid. excess lipid accumulates and damages brain cells |
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Term
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Definition
"power house of the cell"
- synthesis of ATP, sites of cellular respiration
- inner membranes folds into cristae |
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Term
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Definition
-semipermeable/selectively permeable
- controls what enters and leaves the cell
- maintains the cells "homeostasis" (homo = same; stasis = standing)
- keeps the internal chemical composition within narrow limits |
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Term
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Definition
| the movement of materials across the plasma membrane |
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Term
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Definition
| does not require energy from cell |
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Term
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Definition
| molecules move from an area of greater concentraiton ot an area of lesser concentraion |
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Term
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Definition
| a carrier protein combines with a specific substance and moves it across the membrane |
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Term
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Definition
the diffusion of water through a semipermeable membrane (water moves from a higher to lower concentration)
- water moves toward a region of higher solute (dissolved substance)concentration. |
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Term
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Definition
| the control of water balance |
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Term
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Definition
-(iso = same; tonus = tension)
- concentration of dissolved substances are the same inside and outside the cell; no net flow of water |
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Term
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Definition
-(hyper = above/exceeding)
- high solute concentration |
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Term
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Definition
hypo = lower/below
- low solute concentration |
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Term
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Definition
| - (osmotic lysis) bursting of a cell in a hypotonic solution n(taking up the water) |
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Term
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Definition
| - shrinkage of the cytoplasm due to loss of water in a hypertonic solution |
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Term
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Definition
proteins which form channels through the membrane allowing passage of certain molecules.
- gated channels: some can act as "gates" that open and close |
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Term
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Definition
-can move substances against their concentration gradient
- requires that the cell extend energy (ATP) e.g. sodium-potassium pump |
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Term
| transport of large particles |
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Definition
- endocytosis
- exocytosis |
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Term
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Definition
- phagocytosis (cell eating)
- pinocytosis (cell drinking)
- receptor-mediated endocytosis |
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Term
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Definition
| -vacuole fuses with plasma membrane and expels contents from cell |
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