Reading Pages 136-141: Topics to focus on—
... 5. Define transport protein. Do transport proteins have specificity? Tunnel to allow hydrophilic items to pass the membrane that cannot get through the lipid bilayer—very specific (allow glucose but not fructose) 6. Define and explain diffusion. Molecules spread out into available space—random for e ...
... 5. Define transport protein. Do transport proteins have specificity? Tunnel to allow hydrophilic items to pass the membrane that cannot get through the lipid bilayer—very specific (allow glucose but not fructose) 6. Define and explain diffusion. Molecules spread out into available space—random for e ...
03b_TransportMechanisms
... • Facilitated diffusion (no ATP required because movement is down concentration gradient (“downhill”) • Active Transport (ATP required) • Molecules move against concentration gradient (“uphill”) • Ion pumps (e.g., Na-K pump) ...
... • Facilitated diffusion (no ATP required because movement is down concentration gradient (“downhill”) • Active Transport (ATP required) • Molecules move against concentration gradient (“uphill”) • Ion pumps (e.g., Na-K pump) ...
Chapter 5 Homeostasis and Cell Transport PASSIVE TRANSPORT
... Multi-cellular organisms respond to hypotonic environments by pumping solutes out. This helps control the flow of water into the cell. Plants in a hypotonic environment can stand upright. The water fills the cell pressing the cell membrane up against the cell wall which is strong enough to resist br ...
... Multi-cellular organisms respond to hypotonic environments by pumping solutes out. This helps control the flow of water into the cell. Plants in a hypotonic environment can stand upright. The water fills the cell pressing the cell membrane up against the cell wall which is strong enough to resist br ...
6419982_1441921514
... multiplied by the valence of the ion—in this case, by 1). As a result of the unequal distribution of charges between the inside and outside of cells, each cell acts as a tiny battery with the positive pole outside the plasma membrane and the negative pole inside. The magnitude of this charge differe ...
... multiplied by the valence of the ion—in this case, by 1). As a result of the unequal distribution of charges between the inside and outside of cells, each cell acts as a tiny battery with the positive pole outside the plasma membrane and the negative pole inside. The magnitude of this charge differe ...
answer - chemistryaplus
... (c) Hence magnesium atom releases electrons more easily than a copper atom and the magnesium strip act as the negative terminal of the cell. (d) At the negative terminal, each magnesium atom releases two electrons and the Mg2+ formed moved into the solution. Mg(s) Mg2+ (aq) + 2e (e) The electrons ...
... (c) Hence magnesium atom releases electrons more easily than a copper atom and the magnesium strip act as the negative terminal of the cell. (d) At the negative terminal, each magnesium atom releases two electrons and the Mg2+ formed moved into the solution. Mg(s) Mg2+ (aq) + 2e (e) The electrons ...
Plasma Membrane - Westgate Mennonite Collegiate
... made of 2 layers of molecules pass phospholipids called the easily; hydrophillic lipid bilayer ...
... made of 2 layers of molecules pass phospholipids called the easily; hydrophillic lipid bilayer ...
Plasma Membrane - High School of Language and Innovation
... made of 2 layers of molecules pass phospholipids called the easily; hydrophillic lipid bilayer ...
... made of 2 layers of molecules pass phospholipids called the easily; hydrophillic lipid bilayer ...
Plasma Membrane - Fulton County Schools
... made of 2 layers of molecules pass phospholipids called the easily; hydrophillic lipid bilayer ...
... made of 2 layers of molecules pass phospholipids called the easily; hydrophillic lipid bilayer ...
Neuroanatomy PP - Rincon History Department
... Neural communication cont’d The neural membrane only allows certain ions through the membrane. Positively charged sodium and potassium ions and negatively charged chloride ions flow back and forth across the cell membrane, but they do not cross at the same rate. The difference in the flow leads to ...
... Neural communication cont’d The neural membrane only allows certain ions through the membrane. Positively charged sodium and potassium ions and negatively charged chloride ions flow back and forth across the cell membrane, but they do not cross at the same rate. The difference in the flow leads to ...
action potential - HCC Learning Web
... Direct synaptic transmission involves binding of neurotransmitters to ligandgated ion channels in the postsynaptic cell Neurotransmitter binding causes ion channels to open, generating a postsynaptic potential Postsynaptic potentials fall into two categories: – Excitatory postsynaptic potentials (EP ...
... Direct synaptic transmission involves binding of neurotransmitters to ligandgated ion channels in the postsynaptic cell Neurotransmitter binding causes ion channels to open, generating a postsynaptic potential Postsynaptic potentials fall into two categories: – Excitatory postsynaptic potentials (EP ...
Insane in the Membrane
... What about the membrane proteins? Scientists have shown that the proteins float around in that bilayer. Some of them are found on the inside of the cell and some on the outside. Other proteins cross the bilayer with one end outside of the cell and one end inside. Those proteins that cross the layer ...
... What about the membrane proteins? Scientists have shown that the proteins float around in that bilayer. Some of them are found on the inside of the cell and some on the outside. Other proteins cross the bilayer with one end outside of the cell and one end inside. Those proteins that cross the layer ...
Plasma Membrane - Westgate Mennonite Collegiate
... Polar heads are hydrophilic “water loving” Nonpolar tails are hydrophobic “water fearing” Makes membrane “Selective” in what crosses10 ...
... Polar heads are hydrophilic “water loving” Nonpolar tails are hydrophobic “water fearing” Makes membrane “Selective” in what crosses10 ...
Diffusion and Cell Membranes
... Purpose: In this lab, you will use eggs with a dissolved shell as a model for a living cell. You will then predict the results of an experiment that involves the movement of water through a membrane. ...
... Purpose: In this lab, you will use eggs with a dissolved shell as a model for a living cell. You will then predict the results of an experiment that involves the movement of water through a membrane. ...
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.