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47 Cards in this Set
- Front
- Back
Phospholipids are composed of 2 fatty acids attached to a ___________ backbone |
Glycerol |
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Phospholipids have polar and nonpolar regions, and thus are _______________ |
Amphiphilic |
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Proteins within the lipid bilayer are referred to as __________ membrane proteins |
Integral. Ex.) Glucose Transport |
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Highly fluid membranes generally have a high concentration of ________ |
Unsaturated phospholipids |
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The amino acids comprising the intramembrane portion of an integral protein are mostly _________ |
Hydrophobic |
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The net diffusion of water across a semipermeable membrane is known as ________ |
Osmosis |
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If a red blood cell is placed in an isotonic solution, the net movement of water across the cell membrane is ________ (inside/outside the cell) |
Neither
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Which statement is NOT true about facilitated diffusion involving glucose? A.) Requires a transporting protein B.) Requires ATP C.) Requires a specific binding site D.) Is a saturable process |
B.) Requires ATP |
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In co-transport that moves glucose and Na into a cell, Na entry generally is facilitated by the _________ gradient (s) (Concentration/Electrical) |
Both. Concentration and Electrical |
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Engulfment of a bacterium by a macrophage generally is referred to as _______ |
Phagocytosis |
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The sodium-potassium pump is an example _________ |
Active Transport |
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In transport involving the sodium-potassium pump, ___________ is (are) moving against (low to high) a concentration gradient (Potassium/Sodium) |
Both potassium and Sodium |
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In transport involving the sodium-potassium pump, ________ is (are) moving against (positive to positive) an electrical gradient (Potassium/Sodium) |
Sodium |
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Binding of potassium to the sodium-potassium pump most immediately causes ____________ |
Release of bound phosphate from the pump |
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Adenylyl cyclase converts __________ |
ATP to cAMP |
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An activated epinephrine (adrenalin) receptor activates adenylyl cyclase via ____________ |
a G protein |
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Communicating junctions in plants that are lined by plasma membrane are ___________ |
Plasmodesmata |
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ABO blood groups occur because red blood cell membranes express different _____________ |
Glycolipids |
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____________ seal neighboring cells together so that substances can't pass between the cells |
Tight Junctions |
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The major transmembrane proteins in desmosomes are _____________ |
Cadherins |
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A "spot weld" between cells is a __________ |
Desmosome |
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Cells most often bind to the extracellular matrix via __________ |
Hemidesmosomes |
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Desmosomes attach to the ______ of the cytoskeleton |
Intermediate Filaments |
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_____________ Help the immune system identify "self" and "non-self" |
HLA proteins (Human Licoside Anthogens) |
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Cardiac muscle contracts as a syncytium because the muscle cells communicate via __________ |
Gap Junctions |
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___________ can pass through a gap junction |
Glucose, Na, Amino Acid |
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Connexons participate in __________ |
Gap Junctions |
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Plasmodesmata contain desmotubules that connect the __________ in different cells |
Endoplasmic Reticula |
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Passive transport generally include ___________ |
Facilitated diffusion and diffusion of CO2 out of a cell |
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An example of a transmembrane protein or structure is a(n) ____________. |
Integrin, Cadherin, Connexon |
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The net diffusion of water across a semipermeable membrane is known as _________ |
Osmosis |
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Low-density lipoproteins containing cholesterol are usually taken into the cells by the process of _______________ |
Receptor-mediated Endocytosis |
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In a hemidesmosome, the transmembrane protein integrin often binds to _______________, which is the most prevalent protein in extracellular matrices |
Collagen |
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Two molecules that diffuse EASILY through the cell membrane without using carriers, channels, or pumps are _________- and ______________ |
CO2 and O2 |
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"Kinky" phospholipids likely contain more ________ between carbons than do straight phospholipids |
Double Bonds |
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Gap junctions are formed by transmembrane structures called ______________- |
Connexons |
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Most water entering/leaving cells passes through channels called _____________ |
Aquaporen |
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Three cell-cell junctions in animals are _________, ____________, and ______________ |
Tight, Anchoring, and Communicating |
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Which cells in the body likely exhibit tight junctions and why? |
Intestinal cell: prevents toxins from entering the bloodstream |
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Describe how unsaturated phospholipids affect membrane fluidity? |
Unsaturated phospholipids have kinky tails so the membrane can't be packed together making it more fluid. |
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Co-transport of glucose and NA into an intestinal cell doesn't require energy, yet this is described as a secondary active transport mechanism. Explain |
The system only works if you have Na outside and you need energy to keep that high |
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The sodium-potassium pump is an ATPase. Describe how the ATPase activity of the pump regulates the movement of sodium by the pump |
ATP is attached, break off of a phosphate (which is attached and changes the shape of the pump) to release out Na which releases energy |
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Osmosis is net water movement across a semi-permeable membrane. What determines the direction of the net water movement? |
It goes from low to high concentration of a solute |
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Why is facilitated diffusion a saturable process? |
Carriers are filled so you can't go faster. Facilitated diffusion requires carriers going as fast as they can. Increasing concentration won't up.
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For cell membranes, give one specific example of a substance that PRIMARILY uses 1.) simple diffusion, 2.) Facilitated diffusion, 3.) receptor-mediated endocytosis, and 4.) active transport to ENTER a cell |
1.) Simple Diffusion: H20, O2, CO2 2.) Facilitated Diffusion: Glucose 3.) Receptor-Mediated Endocytosis: Low-density lypoprotein 4.) Active transport to ENTER a cell: Potassium |
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Name an animal tissue that contains a communicating junction and describe the purpose of the junction |
Heart; communicating. The purpose is to electrically and metabolically couple cells |
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Starting with binding of sodium to the pump, place the following steps in sodium-potassium transport in the correct order: 1.) dephosphorylation of the pump, 2.) phosphorylation of the pump, 3.) binding of potassium to the pump, 4.) release of sodium from the pump, and 5.) release of potassium from the pump |
2.) Phosphorylation of the pump 4.) Release of sodium from the pump 3.) Binding of potassium to the pump 1.) Dephosphorylation of the pump 5.) Release of potassium from the pump |