Name:
... 4. The “heads” are ________________ and face toward the water. 5. The “heads” and “tails” are arranged in a _______________ bilayer. 6. The fibrous proteins serve as _____________________________________ 7. One type of _________________________ allows water to pass through. 8. Integral (channel) pro ...
... 4. The “heads” are ________________ and face toward the water. 5. The “heads” and “tails” are arranged in a _______________ bilayer. 6. The fibrous proteins serve as _____________________________________ 7. One type of _________________________ allows water to pass through. 8. Integral (channel) pro ...
Document
... Sodium channels open. Sodium ions diffuse into the postsynaptic membrane causing depolarisation, which may initiate an action potential. ...
... Sodium channels open. Sodium ions diffuse into the postsynaptic membrane causing depolarisation, which may initiate an action potential. ...
transport across the membrane
... • is the movement of water from an area of high water conc. to an area of low water conc. across a selectively permeable membrane • Water diffuses readily across membrane, through charged, protein-lined pores in the membrane (remember, water is not lipid-soluble) that will not allow anything else bu ...
... • is the movement of water from an area of high water conc. to an area of low water conc. across a selectively permeable membrane • Water diffuses readily across membrane, through charged, protein-lined pores in the membrane (remember, water is not lipid-soluble) that will not allow anything else bu ...
Megan Sechrist
... The water had to go from a high concentration to a low concentration because it was so dense. Each living cell is surrounded by a selectively permeable cell membrane which allows water to move into or out of the cell by diffusion. The diffusion of water across a selectively permeable membrane plays ...
... The water had to go from a high concentration to a low concentration because it was so dense. Each living cell is surrounded by a selectively permeable cell membrane which allows water to move into or out of the cell by diffusion. The diffusion of water across a selectively permeable membrane plays ...
polar head
... communicate with each other take place through the plasma membrane – It determines what moves into and out of cells. ...
... communicate with each other take place through the plasma membrane – It determines what moves into and out of cells. ...
AP Biology Chapter 48 Neurons Guided Notes
... Graded Potentials and Action Potentials • ___________________ are changes in polarization where the magnitude of the change varies with the strength of the stimulus • These are not the nerve signals that travel along axons, but they do have an effect on the generation of nerve signals ...
... Graded Potentials and Action Potentials • ___________________ are changes in polarization where the magnitude of the change varies with the strength of the stimulus • These are not the nerve signals that travel along axons, but they do have an effect on the generation of nerve signals ...
figures from Lin et al.
... 11. An alien lands on Earth and is found to be exactly like humans in every way. The alien’s neurons have a Na+ equilibrium potential (ENa) of +55 mV, according to the Nernst equation. What is the significance of this value? That is, what happens (or doesn’t happen) at this specific value? [4 pts.] ...
... 11. An alien lands on Earth and is found to be exactly like humans in every way. The alien’s neurons have a Na+ equilibrium potential (ENa) of +55 mV, according to the Nernst equation. What is the significance of this value? That is, what happens (or doesn’t happen) at this specific value? [4 pts.] ...
Virtual Cell Worksheet
... The thick ropy strands are the _____________________________. The large solid spot is the _____________________. The nucleolus is a knot of __________________ chromatin. It manufactures __________________________. Dissolve and move to next page. The nucleolus is a spot of condensed _______________. ...
... The thick ropy strands are the _____________________________. The large solid spot is the _____________________. The nucleolus is a knot of __________________ chromatin. It manufactures __________________________. Dissolve and move to next page. The nucleolus is a spot of condensed _______________. ...
Chapter Two - Texas Christian University
... When the NT binds, local channels open and briefly change the polarity which results in a graded potential. When there are enough graded potentials in succession, channels open allowing positive ions from the outside to enter the interior of the neuron. Entrance of the positive ions into the cell bo ...
... When the NT binds, local channels open and briefly change the polarity which results in a graded potential. When there are enough graded potentials in succession, channels open allowing positive ions from the outside to enter the interior of the neuron. Entrance of the positive ions into the cell bo ...
Document
... -K+ leaks out of cell - inside becomes more negative -K+ is then pumped back in 2. Gated channels: open and close in response to a stimulus A. voltage-gated: open in response to change in voltage - participate in the AP B. ligand-gated: open & close in response to particular chemical stimuli (hormon ...
... -K+ leaks out of cell - inside becomes more negative -K+ is then pumped back in 2. Gated channels: open and close in response to a stimulus A. voltage-gated: open in response to change in voltage - participate in the AP B. ligand-gated: open & close in response to particular chemical stimuli (hormon ...
Active Transport
... of a balloon. The air inside the balloon is more concentrated than the air outside of it. There is a concentration gradient because of the differences in concentration. And what happens when you release the tip of the balloon? The air inside the balloon shoots out because things like it when the con ...
... of a balloon. The air inside the balloon is more concentrated than the air outside of it. There is a concentration gradient because of the differences in concentration. And what happens when you release the tip of the balloon? The air inside the balloon shoots out because things like it when the con ...
Synthesis and Sidedness of Membranes
... • If a plant cell and its surroundings are isotonic, there is no net movement of water into the cell; the cell becomes flaccid (limp), and the plant may wilt ...
... • If a plant cell and its surroundings are isotonic, there is no net movement of water into the cell; the cell becomes flaccid (limp), and the plant may wilt ...
Shier, Butler, and Lewis: Hole`s Human Anatomy and Physiology
... 1. A resting nerve cell is not being stimulated to send a nerve impulse. 2. At rest, a cell membrane gets a slight surplus of positive charges outside, and inside reflects a slight negative surplus of impermeable negatively charged ions because the cell membrane is more permeable to potassium ions t ...
... 1. A resting nerve cell is not being stimulated to send a nerve impulse. 2. At rest, a cell membrane gets a slight surplus of positive charges outside, and inside reflects a slight negative surplus of impermeable negatively charged ions because the cell membrane is more permeable to potassium ions t ...
1. A unicellular protest may use a contractile vacuole to expel
... 1. A unicellular protest may use a contractile vacuole to expel excess water. Contractile vacuoles most likely would be found in protists that are a. In a freshwater environment. b. In a marine environment. ...
... 1. A unicellular protest may use a contractile vacuole to expel excess water. Contractile vacuoles most likely would be found in protists that are a. In a freshwater environment. b. In a marine environment. ...
Cell Transport Power point
... 2. Cell-to-cell recognition: (Transplant issues, blood group, etc. – Ex.) 3. Cell signaling: chem. signals from 1 cell may be picked up by proteins in another cell • for action 4. Transport of Materials: Serve as channels to help some materials cross the plasma membrane (Ex. Sugars) ...
... 2. Cell-to-cell recognition: (Transplant issues, blood group, etc. – Ex.) 3. Cell signaling: chem. signals from 1 cell may be picked up by proteins in another cell • for action 4. Transport of Materials: Serve as channels to help some materials cross the plasma membrane (Ex. Sugars) ...
Chapter 5: PowerPoint
... proteins allow the cell to be selective about what passes through the membrane. Channel proteins have a polar interior allowing polar molecules to pass through. Carrier proteins bind to a specific molecule to facilitate its passage. ...
... proteins allow the cell to be selective about what passes through the membrane. Channel proteins have a polar interior allowing polar molecules to pass through. Carrier proteins bind to a specific molecule to facilitate its passage. ...
Chapter 5: Cell Membrane Structure and Function What Drives the
... Diffusion: Movement of molecules from an area of [high] to an area of [low] Rate depends on: 1) Molecule size 2) Concentration gradient 3) Lipid solubility • Greater the concentration gradient, the faster diffusion occurs • Diffusion will continue until gradient eliminated (dynamic equilibrium) • Di ...
... Diffusion: Movement of molecules from an area of [high] to an area of [low] Rate depends on: 1) Molecule size 2) Concentration gradient 3) Lipid solubility • Greater the concentration gradient, the faster diffusion occurs • Diffusion will continue until gradient eliminated (dynamic equilibrium) • Di ...
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.