Biology 101 Essay Example | Topics and Well Written Essays - 1000 words

Biology 101 - Essay Example ine that the oxygen in CO2 indeed comes from sugar, and not from oxygen gas, cells (e.g bacterial or yeast cells ) that are actively respiring can be given sugar substrate which has been synthesized with the oxygen isotope 18O. The cells are exposed to regular oxygen which carries the commonly occurring 16O isotope. After some time, gases are to be collected from the headspace and subjected to mass spectrometric analysis which can separate the CO2 based on their molecular weights. If the oxygen in the carbon dioxide came from the sugar, it will be present in higher concentration at a higher molecular weight (because the labeled 18O will have heavier mass). If the oxygen came from the air, then the reverse would be true. 2. A food manufacturer is advertising a new cake mix as fat-free. Scientists at the U.S. Food and Drug Administration (FDA) are testing the product to see if it truly lacks fat. Hydrolysis of the cake mix yields glucose, fructose, glycerol, a number of amino acids, and several kinds of molecules with long hydrocarbon chains. Further analysis shows that most of the hydrocarbon chains have a carboxyl group at one end. What would you tell the food manufacturer if you were the spokesperson for the FDA? If I were the spokesperson of the FDA, I would tell the food manufacturer that his claim of a fat-free mix is downright false. Fats and oils are made up of fatty acids that are anchored on a glycerol backbone. Glycerol is a three-carbon compound with 3 carboxylic groups, each can form an ester bond with a fatty acid. For this reason, fats are also called triacylglycerols. Hydrolysis of fats and oils will yield glycerol and three free fatty acids. The free fatty acids are long-chain hydrocarbon compounds (most common fats have 16-18 carbon atoms) with a carboxyl group (-COO) at one end. Further analysis will even show if these fatty acids are either saturated or unsaturated with hydrogen atoms. 3. Imagine that you are a pediatrician and one of your