When the proteins of human gut epithelial cells adhere to each other so tightly that digestive enzymes from the intestinal lumen cannot pass between the cells, these proteins are exhibiting: unrestricted movement, similar to membrane phospholipids (like phosphatidylcholine) restricted movement, based on confinement by diffusion barriers (like tight junctions) restricted movement, based on tethering to extracellular molecules (like collagen) restricted movement, based on attachment to other cells (by proteins like keratin) restricted movement, based on anchoring to intracellular proteins (like spectrin)

Which of the following is not a lipid link that anchors membrane-associated proteins to the bilayer?     Thioether-linked prenyl anchors.     Ester-linked triacylglycerol anchors.     Glycosyl phosphatidylinositol anchors.     Thioester-linked fatty acyl anchors.     Amide-linked myristoyl anchors.

The salt concentration in the cytosol of body cells of seawater fish is lower than it is in their environment. This causes the fish to continually lose water. To compensate for this loss, seawater fish continuously ingest water and rely on membrane-bound proteins on their gills for the removal of salt ions back to the environment. Which of the following describes the most likely mechanism of membrane transport used by seawater fish to remove the salt ions? A B с D exocytosis simple diffusion active transport facilitated diffusion

Where is the KV1.1 (a membrane protein) polypeptide synthesized in the cell?  (word bank: cytoplasm, nucleus, rough ER, smooth ER, mitochondria)    The amino acids that line the outside of the KV1.1 protein (i.e., those in contact with the phospholipid bilayer's fatty acids tails) are more likely to be _______(word bank: hydrophobic, hydrophilic) The KV1.1 protein utilizes __ transport to move the K+ ions across the membrane.  (word bank: active, passive) This disease can be caused by missense mutations.  In general, how specifically would a missense mutation affect the KV1.1 protein?

Which of the following characteristics may be used to describe Active Transport? Select all that apply. occurs without a transporter protein requires an energy source shows saturation kinetics (has a maximum rate) can occur against a concentration gradient (i.e. uphill)

What statement about "peripheral" membrane proteins is INCORRECT?   Hide answer choices  Polar interactions of peripheral protein and polar head groups of the membrane lipids can be disrupted by adding salts or by changing the pH.   They are membrane proteins that are anchored to the membrane by a covalently attached lipid molecule.   They are membrane proteins that interact with the polar head groups of the membrane lipids.   They are membrane proteins that bind to the surfaces of integral proteins.   They are membrane proteins that traverse the lipid bilayer.     2. What is the difference between the T form and R form of the hemoglobin molecule?   Hide answer choices  The T form of the hemoglobin molecule is not constrained by subunit–subunit interactions.   The T form of the hemoglobin molecule is unstable without 2,3-BPG.   The R form of the hemoglobin molecule has the…

Eukaryotic membrane fluidity can be increased by which of the following mechanisms? increasing the number of fatty acids attached to glycerol in membrane lipids decreasing the number of branched chain fatty acids of membrane lipids decreasing the number of carbons in the fatty acids of membrane lipids decreasing the number of membraned organelles in the eukaryotic cell increasing the degree of saturation in the fatty acids of membrane lipids

Glucose is a large molecule that cannot penetrate the phospholipid bilayer of cells. Instead, glucose enters most cells, such as red blood cells, through special carrier proteins embedded in the surface of the plasma membrane. In doing so, glucose moves from an area of high concentration to an area of low concentration. Based on this information, which term best describes the uptake of glucose by red blood cells? O Facilitated diffusion O Simple diffusion O Active transport O Osmosis

When blood glucose level rises, the pancreas secretes insulin, and as a result blood glucose level declines. When blood glucose level is low, the pancreas secretes glucagon, and as a result blood glucose level rises. Such regulation of blood glucose level is the result of A reproduction thermal regulation community homeostasis 2,279 12 tv N MacBook Air DII DD F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F1 @ %23 24 2 6. %3D * CO

How are the ER and Golgi involved in membrane creation? (Think about lipid synthesis and distribution). What are the characteristics of Sphingolipid and cholesterol in the membrane? What does it do to the membrane? Explain raft formation.