Chapter 6-7
Microscopes
Membrane Protien
Electron Microscope
Scanning-Electron Miscroscope
show a 3-D image of the surface of a spedimn
focuses a beam of electrons through the specimen or onto its surface.
Light Microscope
visible light is passed through the specimen and then through glass lenses
Transmission electron microscope
click to edit
Confocal
Flourescence
Phase Contrast
Brightfield
Unstained- light passes directily though the specimen. Very little contrast
Stained- Stained to enhance contrast
Variation in density within the specimen are amplified to enhance contrast in unstained cells.
the location of specific molecules in the cell can be revelaed by labeling the molecules wtih flourescent dyes or antibodies.
using a laser this "optical sectioning teqnique eliminates out of focues light from a think sample, creating a single plane of flourescence in the image
Cell Fractionation
Takes cells apart and seperates major organelles and other subcellular structures from one another.
Comparing Cells
Eukaryotic Cells
Prokaryotic cell
DNA is concentrated in a region that is not membrane-enclosed, called the nucleoid.
Most of the DNA is located in the nucleus which is bounded by a double membrane
Nucleus
Contains most of the genes in the eukaryotic cell.
Endomemdrane System
This system carries out a variety of tasks in the cell, including synthesis of protiens, transport of protiens into membranes and organelles or out of the cell, metabolism and movement of lipids, and detoxification of poisons.
Cell Membrane
Osmosis
Mitochondria
the sites of cellular respiration the metalbolic process that uses oxygen to drive the generation of ATP by extracting every from sugar, fats, and other fluids
Chloroplast
found in plants and algae, are the sites of photosynthesis
Cytoskeleton
a network of fibers extending throughout the cytoplasm
Cell Wall
extracellular structure of plant cells.
Cell Junctions
Desmosomes
Cell Recognition
a cell's ability to distinguish one type of neighboring cell from another
is the spontaneous net movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides.
Cytoplasm
refers to the region between the nucleus and the plasma membrane ,
Plasma Membrane
a sellective barrier that allowes passage of enough oxygen, nutrients, and wates to service the entire cell.
Nuclear Envelope
Encloses the nucleus =, seperatiung its content from the cytoplasm.
Nuclear Lamina
a netlike array of protien filaments that maintain the shape of the nucleus by mechanically supporting the nuclear envelope
Chromosomes
Structures thet carry the genetic information. Each chromosome contains one long DNA molecule associated with many protiens
Chromatin
the complex of DNA and protiens making up chromosomes.
Nucleolus
a promineny structure within the nondividing nucleus
Endoplasmic Reticulum
Rough ER
Smooth ER
Lacks Ribosomes, enzymes of the smooth ER help detoxify drugs and poisons, especailly in liver cells.
Some cells screte proties created by the ribosomes attatched to the rough ER
Ribosomes
complexes made of ribosomal RNAs and protiens, are the cellular components that carry out protien synthesis.
Stores calcium ions, The smooth ER, for example, pumps calcuim ions into the muscle causing it to contract
Glycoprotien
Proteins with carhohydrates covalently bonded to them
Transport protiens
vesicles in transit from one part of the cell to another
it is a membrane factory, it grows in place by adding membrane protiens and phospholipids to its own membrane
Golgi Apparatus
Products of the ER, such as protiens are modified and stored and then sent to other destinations
Warehosue for sorting, shipping, and even manufacturing
Cis
Trans
on the same side- a vesicles that buds from then ER can add its membrane and its contents of it lumen to the cis face by fusing the golgi on the same side
on the opposite side- give rise to vesicles that pinch off and travel to other sites.
Lysosome
a membranous sac of hydroliytic enzymes that many eukaryotic cells use to digest macromolecules
Phagoocytosis
amoedas and many other unicellular eukaryotes eat by engulfing smaller organsims or food particles
Autophagy
lysosomes use their hydrolytic enzymes to recylces the cell's own organic material
Vacuoles
large vesicles derived from the endoplasmic reticulum and golgi apparatus
Contractile vacuoles
pump excess water out of the cell
Central Vacuole
it plays a major role in the growth of plants cells
it enlarges as the vacuoles absord water, enabling the cell to become larger with minimal investment in the new cytoplasm
Cristae
the outer membrane is smooth, but the inner membrarne is convoluted with infoldings
MItochondrial Matrix
Thylakoid
is enclosed by the inner membrane. It contains many different enzymes as well as the mitochondrial DNA and ribosomes
in the chloroplast is a membranous system in the form of flattened, interconnected sacs.
Each sac is called a granum
the fluid outside of the thylakoid is the stroma
Plastids
chromoplasts
amyloplasts
Peroxisome
specialized metabolic compartment bounded by a single membrane
give mechanical support to the cell and maintain its shape
Motor Protiens
they work together with plasma membrane molcules to allow whole cells to move alone fibers outside the cell
Microtubules
hollow robs constructed from globular protiens called tubulines
Centrosomes
Fragella
Cilia
Microfilaments
actin
Cortex
back and forth extention
microtubles grow out from here,
snakelike extension
Intermediate Filaments
are larger than microtubules but smaller than microfilaments
Primary
Middle Lamella
Secondary
Extracellular Matrix
similar to a cell wall of plants
Collagen
Proteoglycan
Integrins
span the membrane and bind on their cytoplasmic side to associated protein attatched to microfilaments of the cystoskeleton
glycoprotien that forms strong fibers outside the cell
consists of a small core protie with many carbohydrates chains convalently attatches
Gap Junction
Tight Junctions
provide cytoplasmuc channels from one cell to an adjcent cell
functions like rivets, fastening cells together onto strong sheets
the plasma membranes of neighboring cells are tightly pressed against each other, bound together by specific protien
shape and support the cell and also serve as a track where organelles with motor protiens can move
Within the centrosomes are a pair of centrioles, each composed of nine sets of trimplets microtubules arranged in a ring
globular protiens
the outer region of cytoplasms
a twisted double chain of actin subunits
can from structural networks when certain protiens bind along the side of such a filament and allow a new filament to extend as a branch
young plants first have a relatively thing and fexilble wall
between the plasme membrane and the primary wall, has a strong durable matric that afford the cell protection and support
a thin layer rich in stiny poylysaccharudes called pectins
Selective Permeability
Amphipathic
its both hydrophilic and hydrophobic
it allows from substances to cross it more easily than others
Fluid Mosiac Model
the membrane is a mosaic of protiens molecules bodding in a fluid bilayer of phospholipids
Integral Protiens
penetrate teh hydrophobic interior of the lipid bilayer
Peripheral Proteins
Glycoprotiens
Glycolipids
membrane carbohydrates that are covlalently bonded to lipids
membrane carbohydrates that are covalently bonded to protiens
Transport Protiens
function by having hydrophilic channels that certain molecules or atomic ions use as tunnels through the membrane
Aquaporins
allows entry of uo to 3 billion water molecules a second
Diffusion
the movement of particles of any substance so that they spread out into the available space
Isotonic
there will be no net movement of water across the plasma membrane
Hypertonic
the cell will lose water, shrivel up and die
Hypotonic
water wil enter the cell faster that it leaves nad the vell will swell and lyse
Osmoregulation
the control of solute concentration and water balance
Turgid
Very Firm
Flaccid
Limp
Active Transport
enabel a cell to maintain internal concentration of small solutes that differ from concentration in its environment
Membrane Potential
ranges from about -50 to -200 millivolts
Proton Pump
the main electrogenic pump of plants, fungi and bacteria
Electrogenic Pump
a transport protien that generates voltage across a membrane
thye are loosly bound to the surface of the membrane, often to expose parts of the integral protiens
Passive transport
the diffusion of a substance across a biological membrane
Tonicity
the ability of a surrounding solution to cause a cell to gain or lose water