Bio Ch 6
Terms
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- Flagella
- Structure aiding movement; found usually 1 at a time, fairly long; beats in an undulating fashion (think sperm)
- Intermediate filaments
- Type of fiber composing cytoskeleton; fibrous proteins supercoiled into thicker cables made up of **** in keratin family; anchors nucleus and other **** and forms nuclear lamina
- Tight junction
- Type of intercellular junction where the membranes of neighboring cells are tightly pressed against each other; prevents leakage of extracellular fluid
- Plasma membrane
- Boundary of every cells that functions as a selective barrier; made of two phospholipid bilayers allowing sufficient passage of nutrients, oxygen, and wastes to service entire volume of cell (which is why cells are teensy, cos high surface area:volume ratio)
- Thylakoids
- Found in the chloroplast, these are flattened, interconnected sacs
- Chromoplasts
- Colorful plastids that have the pigments making fruits and flowers bootiful
- Cells
- Simplest collection of matter that can live and the basic units of structure and function
- Cytoplasmic streaming
- Circular flow of cytoplasm within cells
- Gap junctions
- Aka communicating junctions; Type of intercellular junction that provides cytoplasmic channels from one cell to an adjacent; consists of a special membrane that surrounds a pore thru which ions, etc, may pass; necessary for communication btwn cells
- Organelles
- Subcellular structures
- Plastids
- Family of plant organelles
- Rough ER
- Endoplasmic reticulum that has ribosomes that stud the outer surface of the membrane; secretes imp. Proteins (e.g. insulin from pancreas) and serves as a membrane factory for the cell
- Centrosome
- Region often located near nucleus that is considerd to be a microtubule-organizing center
- Brightfield
- Using either a stained or unstained specimen, this light microscopy research method passes light directly thru specimen
- Scanning electron microscope
- Type of electron telescope in which an electron beam scans the surface of a sample that is usually coated w/ a thin layer of gold; detailed study of the specimen that usually reveals a topography
- Confocal
- Light microscopy method tht uses laser and special optics for optical sectioning of fluorescently-stained specimens, illuminating only a single plane
- Actin
- Globular protein that is the subunit of microfilaments
- Dynein
- Each motor protein extending from 1 microtubule to the next; responsible for the bending movement of cilia and flagella; has a movement akin to a cat climbing a tree
- Chloroplasts
- Type of plastid found in plants that is the site of photosynthesis works by converting sunlight into chemical energy; semi-independent, containing own DNA and ability to reproduce → sep'd into 3 diff compartments
- Stroma
- Fluid outside the thylakoid, contains the chloroplast DNA and ribosomes as well as enzymes
- Cristae
- Infoldings found in the mitochondria inner membrane; divides mitochondria into 2 internal compartments
- Pseudopodia
- Localized contraction by actin and myosin that allow amoeboid movement; extend and contract thru reversible assembly of actin subunits which react w/ myosin to cause contraction that makes actin reassemble into a network
- Cisternal maturation model
- Scientific model posting that the Golgi body is dynamic, w/ cisternae progressing from cis to trans face carrying/modifying cargo as they move
- Tonoplast
- Membrane enclosing the central vacuole in mature plant cells
- Mitochondrial matrix
- Internal compartment of mitochondria that is enclosed by inner membrane; contains may diff enzymes as well as DNA and ribosomes; imp area of cell respiration
- Chlorophyll
- Green pigment found in chloroplasts
- Electron microscope
- Microscope that focuses a beam of electrons thru the specimen or onto its surface; can view specimens 2nm in size
- Plasmodesmata
- Channels that perforate plant cell walls allowing cytosol to pass thru
- Golgi apparatus
- Center of manufacturing, warehousing, sorting, and shipping where products of the ER are modified and stored and sent to other destinations; conssits of flattened cisternae
- Basal body
- Structurally identical to a centriole; serves to anchor the microtubule assembly of flagella/cilia
- Cell ultrastructure
- Term used by biologists to refer to a cell's anatomy as revealed by an electron microscope
- Granum
- One of the stacks found in a thylakoid
- Prokaryotic
- Type of cell that consists of domains Bacteria and Archaea; cell where DNA is concentrated in a region called the nucleoid but has no actual nucleus
- Motor proteins
- Proteins that bringabout the movements of cilia and flagella by gripping microtubules within those organelles and propelling them past each other
- Cell fractination
- Method used to isolate cell components based on size and density; a sample is put thru a centrifuge for a long ass time
- Extracellular matrix
- Composed of glycoproteins secreted by cells, this structure regulates a cell's behavior
- Resolution
- In microscopy, a measure of the clarity of the image; the minimum distance two points can be separated & still be distinguished as 2 points
- Actin-myosin aggregates
- Responsible for the localized contractions of cells (e.g. pinch needed to divide)
- Fluorescence
- In light microscopy, this method shows the locations of specific molecules in the cell by tagging the molecules w/ fluorescent dyes/antibodies which emit visible light
- Middle lamella
- Thin layer rich in pectins (polysaccharides) found between primary cell walls that glues adjacent cells
- Microvilli
- Long, thin projections from certain cells that increase surface area w/o appreciable increase in volume
- Endomembrane system
- System in which many of the eukaryotic cell's membranes belong to; carries out taks such as synthesis of proteins and their transport and other ****
- Phase-contrast
- Light microscopy research method that enhances contrast in unstained cells by amplifying variations in density within specimen
- Cisternae
- Network of membranous tubules and sacs found in the ER
- Transport vesicles
- Vesicles in transport from one part of the cell to another
- Mitochondria
- Organelles which are the site of cellular respiration; contained by 2 bilayers w/ unique collection of proteins
- Differential-interference-contrast
- Like phase-contrast microscopy it uses optical modifications to exaggerate differences in density making img almost appear 3D
- Bound ribosomes
- Type of ribosome that is attached to the outside of the ER or nuclear envelope
- Autophagy
- Process during which a damaged organelle or small amnt of cytosol is digested by lysosomal enzymes allowing cell to continually renew itself
- Nuclear matrix
- A framework of fibers extending throughout the nuclear interior
- Cell wall
- An extracellular structure of plant cells that distinguishes them from animal cells, protecting the plant cell and maintaining its shape; composed of cellulose embedded in a matrix of other polysaccharides and proteins
- Chromosomes
- Discrete units that carry genetic information within the nucleus
- Nuclear lamina
- The nuclear side of the envelope is lined by this netlike array of protein filaments that mains the shape of the nucleus by mechanically supporting the nuclear envelope
- Free ribosomes
- Type of ribosome that is suspended in the cytosol where most of the proteins function
- Peroxisome
- Oxidative organelle that is not part of the endomembrane system; specialized metabolic compartment bounded by single membrane; contains enzymes that transfer H from various substrates to O producing hydrogen peroxide that can be used to break fatty acids down
- Nuclear envelope
- Structure enclosing nucleus and separating it from cytoplasm; a double membrane that has perforations about 100nm in diameter
- Magnification
- In microscopy, the ratio of an objects image size to its real size
- Desmosomes
- Aka anchoring junction; Type of intercellular junction that functions as rivets, fastening cells together into strong sheets
- Endoplasmic reticulum
- Organelle that is such an extensive network of membranes that it accounts for more than half of the total membrane in many euk. cells
- Myosin
- Protein that acts as a motor protein by means of projections that walk along actin filaments; interdigitated w/ thousands of actin filaments arranged parallel
- Cytoskeleton
- Network of fibers extending throughout the cytoplasm that gives cells mechanical support and shape
- Lysosome
- Organelle that is a membranous sac of hydrolytic enzymes that an animal cell uses to digest all kinds of macromolecules; made by rough ER
- Trans face
- Polar side of Golgi that gives rise to vesicles which pinch off and travel to other sites
- Centriole
- Two of these are found in the centrosome; composed of nine sets of triplet microtubules arranged in ring
- Cytosol
- Semifluid substance within the plasma membrane that contains organelles
- Amyloplasts
- Colorless plastids that store starch
- Cilia
- Structure aiding movement; occurs in lg numbers on the cell surface and are teeny; beats in a back-and-forth motion
- Pore structure
- Intricate protein structure that lines each pore in the nuclear envelope and regulates the entry and exit of large macromolecules/particles
- Phagocytosis
- Process meaning "eat vessel"; organisms produce a food vacuole allowing lysosome to fuse to it & digest
- Contractile vacuoles
- Vacuole found in freshwater protests that pump excess water out of the cell maintaining the proper concentration of salts/other molecules
- Chromatin
- Material composing chromosomes; a complex of proteins and DNA → when a cell wants to divide these thin lil fibers condense becoming thick enuf for us to see
- Eukaryotic
- Type of cell that consists of protests, fungi, animals, plants, etc. - everything else; contains a true nucleus bounded by a nuclear envelope
- Collagen
- Most abundant glycoprotein in animals; forms strong fibers outside the cells and accounts for half of the total protein in the human body
- Integrins
- Cell surface receptor proteins that are built into the plasma membrane and bind of the cytoplasmic side to associated proteins; transmit changes between ECM and cytoskeleton
- Central vacuole
- What mature plant cells generally contain; large space developed by coalescence of smaller vacuoles; protects plant by containing poisons & contains reserves of important organic compounds
- Intermembrane space
- Internal compartment of mitochondria that's the narrow region btwn inner & outer membranes
- Primary cell wall
- Thin and flexible wall first secreted by a young plant
- Smooth ER
- Endoplasmic reticulum that has an outer surface w/o ribosomes; important to synthesis of lipids, metabolism of carbs, and detoxification of drugs/poisons; also stores Ca ions that are released in response to neural msg
- Vesicles
- Tiny sacs made of membrane
- Microtubules
- Type of fiber composing cytoskeleton; hollow tubes w/ walls consisting of 13 cols of tubulin molecules; maintains cells shape and helps w/ movement
- Glycoproteins
- Proteins that have carbohydrates covalently bonded to them; majority of secretory proteins
- Ribosomes
- Organelle made of rRNA and protein that carry out protein synthesis; can be either bound or free
- Ultracentrifuges
- Most pwrful centrifuges that can spin as fast as 130,000 rpm and apply forces on specimen 1mil times the force of gravity
- Lumen
- Cavity of the ER aka the cisternal space that is separated from the cytoplasm by the ER membrane
- Nucleolus
- In the nucleus, a mass of densely stained granules and fibers adjoining part of the chromatin; where rRNA is synthesized and proteins are imported from cytoplasm & assembled into ribosomal subunits
- Fibronectin
- Glycoprotein that binds to the cell surface receptor proteins
- Secondary cell wall
- What some cells do to reinforce cell wall; has strong and durable matrix
- Glyoxysomes
- Specialized peroxisome that is found in fat-storing tissues of plant seeds and contain enzymes initiating conversion of fatty acids to sugar which fuels emerging seedling
- Light microscopes
- Microscopes most likely to be used in a laboratory; visible light is passed thru the specimen and then thru glass lenses; lenses refract light in such a way that image of specimen is magnified onto photographic film, etc → can only view 1000x
- Cis face
- Polar side of Golgi located near the ER where material is transported FROM the ER TO the Golgi
- Transmission electron microscope
- Type of electron microscope usually used to study the internal infrastructure of cells; a thin section of specimen has a bunch of electrons shot thru it & an image is created by the pattern of transmitted electrons
- Microfilaments
- Type of fiber composing cytoskeleton; two intertwined strands of actin,; maintains cell shape, contracts muscle, and helps w/ division and ****
- Nucleus
- Organelle that contains most of the genes in the eukaryotic cell
- Proteoglycans
- Glycoproteins of another class that form a woven embedded network w/ collagen fibers