Membrane Lipids and Proteins Quiz

Tight Junctions = Form impermeable junctions encircling the cell Desmosomes = Serve as anchoring junctions scattered like rivets along adjacent cells Gap Junctions = Communicating junction allowing passage of ions and small molecules between cells

Plaque = Buttonlike thickening on the cytoplasmic face of each plasma membrane Cadherins = Thin linker protein filaments extending from plaques and fitting together like zippers Keratin filaments = Intermediate filaments forming part of the cytoskeleton and anchoring cells together

Sperm recognizing an ovum = By the ovum's unique glycocalyx Epithelial cells in the digestive tract = Preventing digestive enzymes and microorganisms from seeping into the bloodstream

<p>Found only on the outer surface, accounts for 5% of total membrane lipids = Glycolipids Makes up 20% of membrane lipid, stabilizes the plasma membrane = Cholesterol Polar region with a hydroxyl group; nonpolar region with a fused ring system = Cholesterol Enriched by glycolipids and glycoproteins, forms a fuzzy, sticky, carbohydrate-rich area at the cell surface = Glycocalyx</p> Signup and view all the answers

<p>Firmly inserted into the lipid bilayer, involved in transport and act as enzymes or receptors = Integral Proteins Not embedded in the lipid bilayer, easily removed without disrupting the membrane, some are enzymes or motor proteins = Peripheral Proteins Involved in transport by acting as channels and carriers = Integral Proteins Attach loosely to integral proteins and support the membrane with a network of filaments = Peripheral Proteins</p> Signup and view all the answers

<p>Have both hydrophobic and hydrophilic regions, most are transmembrane proteins = Integral Proteins Consists of glycoproteins and glycolipids, forming a carbohydrate-rich area at the cell surface = Glycocalyx Many of the membrane proteins in contact with extracellular fluid are glycoproteins with branching sugar groups = Glycocalyx Involve a network of filaments that support the membrane and may act as enzymes or motor proteins = Peripheral Proteins</p> Signup and view all the answers

<p>Stabilizes the plasma membrane = Cholesterol Allows communication with the environment = Membrane Proteins Responsible for most specialized functions in the plasma membrane = Membrane Proteins Forms a carbohydrate-rich area at the cell surface = Glycocalyx</p> Signup and view all the answers

<p>Accounts for 5% of total membrane lipids and has sugar groups at one end making it polar = Glycolipids Found only on the outer surface, accounts for 5% of total membrane lipids = Glycolipids Polar region with a hydroxyl group; nonpolar region with a fused ring system = Cholesterol Enriched by glycolipids secreted by cells and forms a fuzzy carbohydrate-rich area at the cell surface = Glycocalyx</p> Signup and view all the answers

<p>Phospholipids = Lollipop-shaped; has a polar 'head' and is hydrophilic, and an uncharged nonpolar 'tail' composed of fatty acid chains and is hydrophobic Glycolipids = Lipids with attached sugar groups Cholesterol in the Plasma Membrane = Helps regulate membrane fluidity and flexibility Membrane Proteins = Float in the fluid lipid bilayer form a constantly changing mosaic pattern</p> Signup and view all the answers

<p>Plasma Membrane Structure = The fluid mosaic model shows a very thin double layer of lipid molecules with protein molecules dispersed in it Fluid Mosaic Model = Proteins float in the fluid lipid bilayer form a constantly changing mosaic pattern Membrane Lipids = Consist of phospholipids and glycolipids with specific structures Cell Membrane = Plays a dynamic role in cellular activities</p> Signup and view all the answers

<p>Dynamic role in cellular activities = Cell membrane Thin double layer of lipid molecules with dispersed proteins = Plasma Membrane Structure Proteins forming a changing mosaic pattern in the lipid bilayer = Fluid Mosaic Model Lipids shaped like lollipops with hydrophilic heads and hydrophobic tails = Phospholipids</p> Signup and view all the answers

<p>Polar 'head' and nonpolar 'tail' = Phospholipids Attached sugar groups = Glycolipids Similar consistency to olive oil = Phospholipids Hydrophobic tail composed of fatty acid chains = Phospholipids</p> Signup and view all the answers

<p>Helps regulate membrane fluidity and flexibility = Cholesterol in the Plasma Membrane Forms a constantly changing mosaic pattern = Membrane Proteins Plays a dynamic role in cellular activities = Cell Membrane Consists of lollipop-shaped lipids with hydrophilic heads and hydrophobic tails = Phospholipids</p> Signup and view all the answers