Med Biochem Exam 3 Questions With Accurate Answers A+

Med Biochem Exam 3 Questions With Accurate Answers A+ What are epinephrine's effects when binding to receptors in each of the following cells: - Muscle or liver cells - Adipose cells - Heart cells - ANS-- Muscle or liver cells: induces breakdown of glycogen - Adipose cells: induces lipid hydrolysis - Heart cells: increases heart rate Two classes of lipids: - ANS-Based on structure/function Lipids that do not contain fatty acids: cholesterol, terpenes, cofactors for enzymes, etc. Lipids that contain fatty acids: complex lipids. Two types: storage lipids (triacylglycerols containing 3 chains) and membrane lipids (containing 2 chains). Carboxylic acids with hydrocarbon chains containing between 4 to 36 carbons. - ANS-Fatty acids or storage lipids Saturated vs Monounsaturated vs Polyunsaturated: - ANS-Saturated: no double bonds between carbons in the chain Monounsaturated: one double bond between carbons in the alkyl chain Polyunsaturated: more than one double bond in the alkyl chain Why do most natural fatty acids have an even number of carbons? - ANS-Because they are synthesized and broken down in sets of 2 carbons at a time T/F: For saturated fatty acids, the longer the chain = the higher the melting point. - ANS-T. The melting point increases to higher temperatures as the chain grows, meaning it is more difficult to melt the longer chains. For unsaturated fatty acids, the presence of the double bond lowers the melting point as well. Compare saturated and unsaturated fatty acid properties - bonds - solubility - melting point - conformation - ANS-Saturated has carbon chains with no double bonds. Solubility decreases as length increases (longer chain = less soluble). MP increases as length increases (longer chain = higher MP). Conformation: extended conformation/straight. Unsaturated has carbon chains with one or more double bonds. Solubility decreases as length increases (longer chain = less soluble) MP decrease as number of double bonds increases (more double bonds = lower MP). Conformation: double bonds in cis formation causes kinks in chain and less packing. Compare omega-3 and omega-6 fatty acids, the role of each in the body, and why the consumption ratio might be important. - ANS-Omega-3 is an alpha-linolenic acid that is not made by the body and has to be brought in by food. Common foods omega-3 is found in are nuts/seeds, green/leafy vegetables, and fish/vegetable oil. Omega-3 is used to make DHA and EPA. Omega-3 is converted into anti-inflammatory molecules. Omega-6 is a gamma-linolenic acid that is correlated with cardiovascular disease. Omega-6 is converted to molecules that increase inflammation in the body. Consumption ratio is supposed to be between 1:1 and 4:1 (omega-6 to omega-3) which is correlated with decreased risk of inflammation in arthritis or asthma, and even decrease in cancer growth. However, the U.S. consumes a ration well over 10:1, and this over-consumption of omega-6 could be dangerous. A trans double bond allows a fatty acid to: - ANS-It allows a fatty acid to adopt an extended conformation, pack more regularly, and have higher melting points than cis form. Which has a higher melting point: cis or trans fatty acids? - ANS-trans fatty acids How are artificial trans fatty acids formed? Why? - CONTINUES...