plasma membrane, nucleus, cytoplasm
What are the three prominent features of every cell?
lipids
PLASMA MEMBRANE
______ are the main structural components of membranes.
phospholipid
PLASMA MEMBRANE:
Contains phosphate head and a tail composed of fatty acid chains.
negatively, hydrophillic
PLASMA MEMBRANE:
The head of the phospholipid is _____ charged and ____.
nonpolar
PLASMA MEMBRANE:
The tail of the phospholipid is ___ and there for hydrophobic.
tail to tail
PLASMA MEMBRANE:
The phospholipids associate ___ ___ __ in the bilayer.
ecf, cytosol
PLASMA MEMBRANE:
The hydrophillic head (negatively charged phosphate) faces the aqueous environment of either the ____ or the ___.
inward
PLASMA MEMBRANE:
Hydrophobic tails (nonpolar fatty acid chains) point ___ toward each other so that they are shielded from water.
selective permeability
PLASMA MEMBRANE:
Hydrophobic interior of membrane contributes to ___ ___.
selectively permeable
A membrane that allows certain substances to pass while restricting the movement of others; also called differentially ___ membrane.
nonpolar, uncharged
PLASMA MEMBRANE:
The lipid bilayer is permeable to ____, ____ molecules
glucose
PLASMA MEMBRANE:
Which one of these are NOT permeable to the lipid bilayer unless a specific transporter is present?
O2, carbon dioxide, glucose, lipids, steroids
transporter
PLASMA MEMBRANE:
Ions and large, polar molecules are not permeable unless a specific ____ is present.
mosaic
DESCRIBING THE FLUID MOSAIC :
____ Because diverse proteins are embedded in a framework of phospholipids.
fluid
DESCRIBING THE FLUID MOSAIC:
___ because most of the individual proteins and phospholipid molecules can drift with in the membrane.
cholesterol, fluidity
PLASMA MEMBRANE:
____ wedges into the lipid portion of the bilayer to add to the ___ of the membrane.
unsaturated, fluid
PLASMA MEMBRANE:
_______ fatty acid tails of phospholipids: "kinks" make the membrane more ____ by preventing adjacent phospholipids from packing tightly together.
carb chain, identification
PLASMA MEMBRANE:
______ ____: On surface are attached to proteins and lipids in the membrane many function as cell _____ tags.
integral
PLASMA MEMBRANE, ARRANGEMENT OF PROTEIN:
amphipathic proteins that extend through lipid bilayer.
peripheral
PLASMA MEMBRANE, ARRANGEMENT OF PROTEIN:
proteins associated with one side of the bilayer or with an integral protein.
amphipathic
Pertains to a molecule containing both polar (water-soluble) and nonpolar (not water-soluble) portions in its structure
glycoproteins
PLASMA MEMBRANE, ARRANGEMENT OF PROTEIN:
proteins with carbs attached that form "glycocalyx
transport
FUNCTION OF THE PLASMA MEMBRANE:
A protein that spans the membrane may provide a hydrophillic channel across the membrane that is selective for a particular solute. Some ____ proteins hydrolyze ATP as an energy source to actively pump substances across th
receptors for signal transduction
FUNCTION OF THE PLASMA MEMBRANE:
A membrane protein exposed to the outside of the cell may have a binding site with a specific shape that fits the shape of a chemical messenger, such as a hormone. The external signal may cause a change in shape in the pro
attachment to cytoskeleton and ecm
FUNCTION OF THE PLASMA MEMBRANE:
Elements of the cytoskeleton (cell's internal supports) and the extracellular matrix (fibers and other substances outside the cell) may be anchored to membrane protiens, which help maintain cell shape and fix the location
enzymatic activity
FUNCTION OF THE PLASMA MEMBRANE:
A protein built into the membrane may be an enzyme with its active site exposed to substances in the adjacent solution. In some cases, several enzymes in a membrane act as a team that catalyzes sequential steps of a metabo
intercellular joining
FUNCTION OF THE PLASMA MEMBRANE:
Membrane proteins of adjacent cells may be hooked together in various kinds of intercellular junctions. Some membrane proteins (CAMs) of this group provide temporary bindind sites that guide cell migration and other cell-t
cell to cell recognition
FUNCTION OF THE PLASMA MEMBRANE:
Some glycoproteins (proteins bonded to short chains of sugars) serve as identificaction tags that are specifically recognized by other cells.
junction
A membrane _____ is a connection between cells.
tight
Impermeable junctions prevent molecules from passing through the intercellular space.
epithelial
Tight junctions between ___ cells lining the digestive tract keep digestive enzymes and microorganisms in the intestine from seeping into the blood stream.
desmosome
Anchoring junctions bind ajacent cells together and help form and internal tension reducing netweork of fibers.
skin, heart muscle
Desmosomes distribute tension through out a cellular sheet and reduces the chance of tearing when it is subjected to pulling forces. Abundant in tissues subjected to mechanical stress such as ___ and ___.
gap
Communicating junctions allow ions and small molecules to pass from one cell to the next for intercellular communication.
heart, smooth
Gap junctions are present in electrically excitable tissues, such as the __ and __ muscle, where ion passage from cell to cell helps synchronize their electrical activity and contraction.
diffusion
The movement of molecules from an area of higher concentration to an area of lower concentration.
equilibrium
Diffusion occurs until _____ is reached.
kinetic energy
Diffusion is caused by the ___ ___ of molecules.
equally
Once equilibrium is reached, molecules will be moving ____ in all directions.
selective permeability
___ ___ allows cells to establish concentration gradieents across the plasma membrane.
concentration gradient
A difference in the concentration of a chemical from one place to another, such as from the inside to the outside of a cell.
passive
A ____ process moves substances across the membrane with out any energy input from the cell.
active
In a ____ process, the cell provides the metabolic energy needed to move substances across the membrane.
electrical gradient
Inner surface of plasma membrane tends to be more negative than outer surface of plasma membrane. I.E. An accumulation of anions in the interior of a plasma membrane.
membrane potential
Electrical gradient that occurs across a cell mmebrane
carrier, channel
What are the two facilitated diffusions?
concentration gradient
In a passive process, the driving force is a ___ ____ of molecule moving aross membrane.
number
In a passive process, the limiting factor for facilitaed diffusion is the __ of protein transporters in the membrane.
faster
The steeper the concentration gradient, the ___ something diffuses.
faster
The higher the temperature, the ___ substances diffuse.
slower
The greater the mass of a diffusing substance, the ____ the rate of diffusion.
faster
The more surface area available for diffusion, the ___ diffusion will occur.
slower
The further the distance a subject has to travel to diffuse, the ___ the rate of diffusion,
Osmolarity
The number of solute particles in 1L of a solutions. (Total solute concentration of the solution)
solvent, solute
In a solution; what ever there is more of is called the ___ and what ever there is less of is called the ____.
high, low
Water will move from an area of ____ water concentration, to an are of ____ water concentration via osmosis.
tonicity
The tendency of a cell to gain or lose water.
isotonic
A solution with a solute cpncentration that is essentially equal to that of the cell.
isotonic
solution; cell gains water at the same rate it loses it. Cell volume remains unchanged.
hypotonic
A solution with a solute concentration lower than that of the cell.
hypotonic
solution; cell gains water faster than it loses water. Causes cell to lyse
hypertonic
A solution with a solute concentration high than that of the cell.
hypertonic
solution; cell loses water faster than it gains water. Cell crenates.
active transport
The movement of a substance across a biological membrane against its concentration gradient, aided by specific transport proteins and requiring a net input of energy. (Usually atp)
simple diffusion
Net movement of molecules froma n area of their high concentration to an area of their lower concentration along their concentration gradient.
facilitated
same as simple diffusion, but the diffusing substance is attached to a lipid soluble membrane carrier protein or moves through a membrane channel.
osmosis
Simple diffusion of water threough a selectively permeable membrane.
cytosol
Active transport allows a cell to maintain concentrations of small molecules in the ____ that are different from the concentration in the ecf.
solute pumps
The active transporters, or ___ ___, move solutes uphill against gradient in Active transport.
na+, k+, ca^2+ , cl-
What are the 4 most important ions in the body that are transported via active transport?
outside
NA+, CA^2+, and CL- are found ____ the cell.
inside
NA+, CA^2+, and CL- will move _____ the cell via active transport because the ___ of the cell has a lower concentration of those.
inside
K+ are found ___ the cell.
outside
During active transport, K+ will move ____ the cell because the ___ has a lower concentration.
primary active transport
energy derived from ATP hydrolysis changes the shape of the transporter protein, which pumps a substance across a membrane against its concentration gradient.
secondary active transport
Potential energy stored in a NA+ or H+ gradient established by primary active transport is used to drive other substances across the membrane against their concentration gradients.
symport
In a secondary active transport; if both substances being transported move in the same direction.
anti port
In a secondary active transport; if both substances being transported move "wave to each other" as they cross the membrane in opposite directions.
sodium potassium pump
what is the most popular "pump" in active transport?
na+-k+ ATPase
The sodium potassium pump is and enzyme called...
energy coupling
secondary active transport is called ___ ___ because they move more than one substance at a time.
vesicle
Small, spherical sac formed by part of the membrane of a cell-- transports substances from one structure to another inside cells.
vesicular transport
Fluids contains large particles and macromolecules are transported across cellular membranes insice membranous sacs called vesicles.
exocytosis
Vesicular transport processes that eject substances from the cell interior into the ecf.
endocytosis
Vesicular transport processes in which the cell ingests small patches of the plasma membrane and moves substances from the cell exterior to the cell interior, or cytosol.
phagocytosis, pinocytosis, receptor mediated
What are the three types of endocytosis?
phagocytosis
endocytosis; The cell engulfs a large particle by forming pseudopods around it and enclosing it with in a membrane sac called a phagosome.
ingested
In most cases, a phagosome is fused with a lysosome and its contents are ___. Anything that can't be ___ are ejected from the cell via exocytosis.
pinocytosis
endocytosis; The cell gulps drops of ecf containing solutes into tiny vesicles. No receptors are used, sp the process is nonspecific. Most vesicles are protein coated.
receptors
In phagocytosis; The vesicle may not be protein coated but has ___ capable of binding to a microorganism or solid particles.
receptor mediated
endocytosis; extracellular substances bond to specific receptor proteins in regions of coated pits, enabling the cell to ingest and concentrate specific substances (liglands) in protein coated vesicles.
liglands
receptor mediated; ____ may simply be released inside the cell, or combined with a lysosome to digest contents.
receptor mediated
In which type of endocytosis are the receptors recylced to the plasma membrane via vesicle?
2, 1, 4, 3
PLACE THESE ITEMS IN THE CORRECT ORDER. EXAMPLE OF CHOLESTEROL UPTAKE VIA RECEPTOR MEDIATED ENDOCYTOSIS.
exocytosis
The movement of materials out of the cytoplasm of a cell via membranous vesivles or vacoules.
exocytosis
Secretion of proteins, such as enzymes (e.g. pepsin) or peptide hormones (e.g. insulin) occurs by ___.
3,1,2,4
LABEL THE STEPS OF EXOCYTOSIS.
resting membrane potential
Voltage that exsists across a cell mrmbrane in an unstimulated cell; occurs when rate of K+ efflux equals the rate of K+ influx.
permeable
The resting membranw potential is largely determiend by K+ because the membrane is much more permeable to K+ that Na+ at rest. The active transport of sodium and potassium ions by the Na+-K+ pump maintains these conditions.
negative
RESTING MEMBRANE POTENTIAL:
Step one) K+ diffuse down their concentration gradient (out of the cell) via leakage channels. Loss of K+ results in a ___ charge on the inner plasma membrane surface
into
RESTING MEMBRANE POTENTIAL:
step two) K+ also move ___ the cell because they are attracted to the negative charge established on the inner plasma membrane.
negative
RESTING MEMBRANE POTENTIAL:
step three) A ___ membrane potential is established when the movement of k+ out of the cells equals movement into the cell. At this point, the concentrstion gradient promoting K+ exit exctly opposes the electrical gradient for
nucleus
Subcellular organelle that contains most of the cell's DNA, site of DNA replication and of transcription
transcription
generation of RNA from DNA template.
nuclear envelope, chromatin, nucleolus
What are the three prominent feautures of the nucleus?
nuclear envelope
Double membrane perforated with pores that controls the flow of materials into and out of the nuclear compartment.
lamina
The Nuclear ____ netlike and composed of intermediate filaments. This give strength and reinforcement to the nuclear envelope.
nucleoli
Sites of ribosome synthesis
nucleolus
Prominent structure of the nucleus; building bloacks of ribosomes are produced here and exit the nucleus via nuclear membrane pores.
chromatin, diffuse
The combination of DNA and proteins that constsitutes chromosomes; very __ when a cell is not dividing, condensed when cell divides.
histone
CHROMATIN; Provide a physical means for packing the very long DNA molecules in a compact, orderly way, but they also play an important role in gene regulation.
nucleosome
CHROMATIN; 8 histone proteins wrapped by two winds of the DNA double helix.
30, 60, 10
Chromatin is composed of ____% DNA, ____% hhistone proteins, and _____% new or forming RNA chains.
cytosol, cytoskeleton, organelles
The cytoplasm includes which 3 basic things?
cytosol
Fluid portion of cytoplasm that surrounds organelles. (intracellular fluid)
70,90, dissolved
The cytosol is composed of ____ to ___% water and contains ___ and suspended components such as ions, glucose, amino acids, fatty acids, proteins, lipids, atp, cellular waste.
cytosol
Where does glycolysis occur?
cytoskeleton
A network of protein filaments that extends throughout the cytosol and beneath the plasma membrane of the cell.
membrane bound organelles
Subcellular compartments that have specific functions. (specialized labor)
cellular structures
subcellular structures with out a cell membrane component such as robosomes or centrosomes.
cytoskeleton
The ___ supports cellular structures and provides the machinery to generate various cell movements.
microfilaments
Cytoskeleton; _____ functions: formation of cellular structures, movement of the cell, mechanical support, cellular contraction.
microfilaments
Cytoskeleton component; looks like twisted beads and are responsible for contracile ring that allows for cleavage furrow.
intermediate filaments
desomosomes are reinforced by these. Look like twislers
intermediate
Cytoskeleton; ___ function: provide tensil strength, stabilization of position of organelles, cell to cell adhesion, resistance to mechanical stress.
microtubules
cytoskeleton; _____ function: determine cell shape, movement of organelles, movement of chromosomes during mitosis, formation of special structures.
microtubules
structure of cytoskeleton; spherical in shape and forms the mitotic spindle during mitosis.
ribosome
Cite of protein synthesis.
rough er
organelle: synthesis of glycoproteins, secretory proteins, membrane proteins, and organelle proteins as well as generation of new membrane.
smooth er
organelle; lipid synthesis, ca^2+ storage for muscle cells, release of glucose to the bloodstream.
ovary, liver, muscle
Cells rich with smooth er; steroidogenic cells of __ and testes, __ cells that detox drugs, __ cells.
golgi apparatus
organelle; Consisting of stacks of membranous "sacs" that modify, store, and package products of the ER.
lysosomes
organelle; Consist of digestive hydrolytic enzymes in an acidic environment enclosed in a membranous sac.
lysosome
___ are formed by the combined actions of the rough ER and the golgi apparatus
lysosomal
Human white blood cells ingest bacteria into vacuoles, and ___ enzymes empty into vacuole to rupture bacterial cell walls.
recycling
Lysosomes also act as a ___ center for cells; damaged cells degraded into "building blocks" and available for generation of new organelles.
mitochondria
where most of the ATPcomes from; glycolysis of cell resp occurs here.
matrix
During glycolysis, the krebs cycle occurs in the ___ of the mitochondria.
inner
During glycolysis, the ETC occurs across the ____ mitochondrian membrane.