CHEM 210 Biochemistry Module 5 Exam – With 100% Correct Answers

Glycerol contains how many alcohol functional groups? 1 2 3 4 None of the above 3 Which of the following are derived from or made from fatty acids? Cholesterol Carotenoids Phosphoglycerides Both A and B Both A and C PHOSPHOGLYCERIDES Question 3 3 / 3 pts Triacylglycerols are made from: A glycerol backbone Three fatty acids Amide linkages between fatty acids A glycerol backbone and three fatty acids All of the above A GLYCEROL BACKBONE AND THREE FATTY ACIDS B Question 5 3 / 3 pts A is a carboxylic acid that is a structural component of lipids. Amino acid Carotenoid Sphingolipid cholesterol None of the above NONE OF THE ABOVE A particular lipid is a liquid at room temperature, so it is called a(n) . Oil Fat Lipid Membrane Sphingolipid OIL Identify the lipid class given by the structural formula: Phosphoglyceride Sphingolipid Cholesterol Triacylglycerol None of these PHOSPHOGLYCERIDE are a class of membrane proteins that are firmly associated with the membrane bilayer. Peripheral protein Integral protein Channel protein Transport protein Inner transmembrane protein INTEGRAL PROTEIN Isoprene units are used to make . A. Cholesterol B. Carotenoid molecules C. Vitamin K D. Both A and C E. All of the above E. ALL OF THE ABOVE Which notation is for a fatty acid with two double bonds? A) 18:1( Δ Δ9,13) B) 18:2(Δ9,13) C) 14:1(Δ9,13) D) 2:18(Δ9,13) E) 14:1:2(Δ9,13) B Which notation indicates a 20-carbon omega-3 fatty acid that contains no other double bonds? A) 20:1 (Δ11) B) 20:1Δ18) C) 20:1(Δ17) D) 20:1(Δ3) E) 20:3(Δ3omega) C is used as the backbone molecule in the formation of storage fats. Ceramide Glucose Sphingolipid Glycerol Phosphoglycerol GLYCEROL Which types of membrane lipids determine the blood type of humans? Triacylglycerols Phosphoglycerides Cholesterol Fatty acids Sphingolipids SPHINGOLIPIDS Sphingolipids are found in high concentrations in the membranes of . organelles myelin sheaths all cells heart cells Vitamin K lipids MYELIN SHEATHS In a sphingolipid, the fatty acids are attached at carbon-2 by this type of linkage? Amide linkage An ether linkage An alcohol linkage A peptide linkage Alkyl linkage AMIDE LINKAGE Membrane proteins: Are sometimes peripheral Are sometimes integral Assist in the transport of molecules Can get nutrients in and the waste molecule out of the cell All are correct ALL ARE CORRECT Peripheral membrane proteins Go all the way through the membrane and are firmly attached to the membrane Are firmly attached to the membrane Are lipids that can be either on the top of the cell or bottom of the cell Are associated with the inside or outside surface of the membrane None of the above ARE ASSOCIATED WITH THE INSIDE OR OUTSIDE SURFACE OF THE MEMBRANE Which statement best describes a general feature of membranes? Individual lipid molecules are free to move in the membrane The interior of the lipid bilayer is very polar The membrane breaks easily The polar heads face inward The membrane is rigid INDIVIDUAL LIPID MOLECULES ARE FREE TO MOVE IN THE MEMBRANE The following cartoon drawing represents which lipid type? Fatty Acid Triacylglycerol Phosphoglyceride Cholesterol None of these PHOSPHOGLYCERIDE Which vitamin is critical for blood coagulation? Vitamin A Vitamin B Vitamin C Vitamin D Vitamin K VITAMIN K is not found in membrane bilayers. Cholesterol Sphingolipid Triacylglycerol Phosphoglycerides All of these TRIACYLGLYCEROL What molecule that protects against UV rays is found both in bacteria and in the eyes? Sphingolipids Carotenoid Triacylglycerol Cholesterol Water CAROTENOID What molecule has four fused rings in its structure? Sphingolipid Carotenoid Triacylglycerol Cholesterol Water CHOLESTEROL In triacylglycerols, fatty acids are attached to glycerol via a/an linkage. -O-CO- -NH- -O-NH- -COO- -C=C- -O-CO- A lipid is . A fat An oil A molecule that dissolves in a non-polar solvent Is made from isoprene units Is water soluble A MOLECULE THAT DISSOLVES IN A NON-POLAR SOLVENT (Short answer) A particular fatty acid molecule has two bends, or kinks, in its structure. What is the cause of the bending or kinking? Double bonds cause the fatty acids to bend or kink about in solution. These double bonds reduce the packing structure of fatty acids making them more liquid-like. Question 27 (short answer) Where in the cell are membranes found? They make up the cell. The cell, itself, and the organelles have membranes. Question 28 5 / 5 pts (short answer) What type of lipid contains a ceramide? What is the purpose of this lipid? Sphingolipids. Sphingolipids are structural lipids that form membrane bilayers with specific functions. Sphingomyelins are a subtype of sphingolipids that occur in all membrane bilayers but are especially prominent in the myelin sheath of some neurons. This subclass of sphingolipids typically has a polar head group with a neutral charge. Another vital function of sphingolipids is that they define the blood type of individuals. (short answer) What is the most significant chemical difference between triacylglycerols and phosphoglycerides that lead to their different functions? Triacylglycerols are nonpolar molecules that can be stored as energy. Phosphoglycerides have both polar and nonpolar regions that permit them to interact with both polar and nonpolar environments making them perfect for membrane bilayers. Question 30 5 / 5 pts (short answer) What is the fluid mosaic model and what feature of the cells does it help us understand? The fluid mosaic model helps us understand biological membranes. It describes the fluid, complex nature of the membrane bilayer. Membranes have lipids and proteins in a rich mixture to help the cell survive.