fluid mosaic model
... FUNCTIONS OF PLASMA MEMBRANE Cellular Attachment Cell membranes have junctions – surfaces which interlock keeps cells together – and surfaces which attach them to the extra cellular matrix. ...
... FUNCTIONS OF PLASMA MEMBRANE Cellular Attachment Cell membranes have junctions – surfaces which interlock keeps cells together – and surfaces which attach them to the extra cellular matrix. ...
Elena Aragon
... Cells without walls that are immersed in an isotonic environment, there will be no net movement of water across the plasma membrane, because water is flowing across the membrane at the same rate in both directions. Thus, in an isotonic environment, the volume of a cell without walls is stable. In a ...
... Cells without walls that are immersed in an isotonic environment, there will be no net movement of water across the plasma membrane, because water is flowing across the membrane at the same rate in both directions. Thus, in an isotonic environment, the volume of a cell without walls is stable. In a ...
membranes and transport
... basis for excitability in nerve and muscle cells. Where is the cell more negative? Inside or out? Inside! This is important for propogation of signals in neurons • Export of sodium from the cell provides the driving force for several facilitated transporters, which import glucose, amino acids and ot ...
... basis for excitability in nerve and muscle cells. Where is the cell more negative? Inside or out? Inside! This is important for propogation of signals in neurons • Export of sodium from the cell provides the driving force for several facilitated transporters, which import glucose, amino acids and ot ...
Slide 1
... Head end of the phospholipids molecule contains phosphate portion, which is relatively soluble in water (polar, hydrophilic). The tail is insoluble ( nonpolar, hydrophobic). ...
... Head end of the phospholipids molecule contains phosphate portion, which is relatively soluble in water (polar, hydrophilic). The tail is insoluble ( nonpolar, hydrophobic). ...
Scientific Method
... Protein molecules are embedded in the lipid bilayer. Most of the proteins extend all the way through the bilayer, and are similar to channels. There are many different kinds of proteins in the membrane. Some of these proteins help transport materials in and out of the cell, while others help with c ...
... Protein molecules are embedded in the lipid bilayer. Most of the proteins extend all the way through the bilayer, and are similar to channels. There are many different kinds of proteins in the membrane. Some of these proteins help transport materials in and out of the cell, while others help with c ...
Class Notes
... The solute molecule is too large to pass -- only the water diffuses until equilibrium is reached. Large molecules or those with a charge need the help of a protein to pass across a cell membrane Proteins form a channel and molecules move through the “doorway” Each channel is specific to a particular ...
... The solute molecule is too large to pass -- only the water diffuses until equilibrium is reached. Large molecules or those with a charge need the help of a protein to pass across a cell membrane Proteins form a channel and molecules move through the “doorway” Each channel is specific to a particular ...
Cell Membranes: Chapt. 6
... • Big molecules and charged ones do NOT pass through • Semi-permeable / selectively permeable ...
... • Big molecules and charged ones do NOT pass through • Semi-permeable / selectively permeable ...
Plasma Membrane
... Integral proteins are the hard workers of the cell membrane. Some integral proteins cross the membrane and act as pathways for ions and molecules. Some of the ion movement may not require work (passive transport), but other processes require lot of energy and pumping action (active transport). When ...
... Integral proteins are the hard workers of the cell membrane. Some integral proteins cross the membrane and act as pathways for ions and molecules. Some of the ion movement may not require work (passive transport), but other processes require lot of energy and pumping action (active transport). When ...
HERE
... is called a(n) _lipid bilayer __. 3. The lipid bilayer forms because there is __water__ both inside and _outside_ of the cell. 4. The phosphate _head_ of a phospholipid is polar. It is _attracted_ to water. 5. The long fatty acid _tails_ of a phospholipid are nonpolar. They are _afraid of/ repelled ...
... is called a(n) _lipid bilayer __. 3. The lipid bilayer forms because there is __water__ both inside and _outside_ of the cell. 4. The phosphate _head_ of a phospholipid is polar. It is _attracted_ to water. 5. The long fatty acid _tails_ of a phospholipid are nonpolar. They are _afraid of/ repelled ...
07-2010C
... Sometimes the transporters pump ions that cause an electrical gradient to from across the membrane ...
... Sometimes the transporters pump ions that cause an electrical gradient to from across the membrane ...
File - Mrs. Burchette`s Class
... Diffusion and Osmosis • Diffusion: net movement of molecules from an area of high concentration to an area of low concentration. • Example: Sugar or salt dissolving in water. Think Koolaide, instant coffee or tea, Crystal Lite ...
... Diffusion and Osmosis • Diffusion: net movement of molecules from an area of high concentration to an area of low concentration. • Example: Sugar or salt dissolving in water. Think Koolaide, instant coffee or tea, Crystal Lite ...
Ch11AB
... Graded potentials are _________________, ____________________ changes in the membrane potential. Graded potentials can be __________________or _______________________. The ___________________ of a graded potential varies directly (is graded) with stimulus strength. (Slide 10) The ___________________ ...
... Graded potentials are _________________, ____________________ changes in the membrane potential. Graded potentials can be __________________or _______________________. The ___________________ of a graded potential varies directly (is graded) with stimulus strength. (Slide 10) The ___________________ ...
1c - Cell Membrane Notes
... hyper = above A solution in which the concentration is higher outside the cell than inside. ...
... hyper = above A solution in which the concentration is higher outside the cell than inside. ...
11: Fundamentals of the Nervous System and Nervous Tissue
... The neuron cell membrane is polarized, being more negatively charged inside than outside. The degree of this difference in electrical charge is the resting membrane potential. ...
... The neuron cell membrane is polarized, being more negatively charged inside than outside. The degree of this difference in electrical charge is the resting membrane potential. ...
The cell - WordPress.com
... The diffusion of water across a plasma membrane it occurs whenever there is an unequal concentration of water on their side of a selectively permeable membrane. Normally, body fluids are isotonic to cells- there is an equal concentration of substances (solutes) and water (solvent) on both sides of p ...
... The diffusion of water across a plasma membrane it occurs whenever there is an unequal concentration of water on their side of a selectively permeable membrane. Normally, body fluids are isotonic to cells- there is an equal concentration of substances (solutes) and water (solvent) on both sides of p ...
Membrane potential
Membrane potential (also transmembrane potential or membrane voltage) is the difference in electric potential between the interior and the exterior of a biological cell. With respect to the exterior of the cell, typical values of membrane potential range from –40 mV to –80 mV.All animal cells are surrounded by a membrane composed of a lipid bilayer with proteins embedded in it. The membrane serves as both an insulator and a diffusion barrier to the movement of ions. Ion transporter/pump proteins actively push ions across the membrane and establish concentration gradients across the membrane, and ion channels allow ions to move across the membrane down those concentration gradients. Ion pumps and ion channels are electrically equivalent to a set of batteries and resistors inserted in the membrane, and therefore create a voltage difference between the two sides of the membrane.Virtually all eukaryotic cells (including cells from animals, plants, and fungi) maintain a non-zero transmembrane potential, usually with a negative voltage in the cell interior as compared to the cell exterior ranging from –40 mV to –80 mV. The membrane potential has two basic functions. First, it allows a cell to function as a battery, providing power to operate a variety of ""molecular devices"" embedded in the membrane. Second, in electrically excitable cells such as neurons and muscle cells, it is used for transmitting signals between different parts of a cell. Signals are generated by opening or closing of ion channels at one point in the membrane, producing a local change in the membrane potential. This change in the electric field can be quickly affected by either adjacent or more distant ion channels in the membrane. Those ion channels can then open or close as a result of the potential change, reproducing the signal.In non-excitable cells, and in excitable cells in their baseline states, the membrane potential is held at a relatively stable value, called the resting potential. For neurons, typical values of the resting potential range from –70 to –80 millivolts; that is, the interior of a cell has a negative baseline voltage of a bit less than one-tenth of a volt. The opening and closing of ion channels can induce a departure from the resting potential. This is called a depolarization if the interior voltage becomes less negative (say from –70 mV to –60 mV), or a hyperpolarization if the interior voltage becomes more negative (say from –70 mV to –80 mV). In excitable cells, a sufficiently large depolarization can evoke an action potential, in which the membrane potential changes rapidly and significantly for a short time (on the order of 1 to 100 milliseconds), often reversing its polarity. Action potentials are generated by the activation of certain voltage-gated ion channels.In neurons, the factors that influence the membrane potential are diverse. They include numerous types of ion channels, some of which are chemically gated and some of which are voltage-gated. Because voltage-gated ion channels are controlled by the membrane potential, while the membrane potential itself is influenced by these same ion channels, feedback loops that allow for complex temporal dynamics arise, including oscillations and regenerative events such as action potentials.