Organic Compounds and Macromolecules - 2.pptx - Biology PDF

Carbohydrates Exploring macromolecules: carbohydrates Carbohydrates are the body's main fuel source Range from small sugar molecules (monomers = monosaccharides) to large polysaccharides. Contain hydroxyl groups and a carbonyl group. Many sugars are labelled with the suffix -ose...

Carbohydrates Exploring macromolecules: carbohydrates Carbohydrates are the body's main fuel source Range from small sugar molecules (monomers = monosaccharides) to large polysaccharides. Contain hydroxyl groups and a carbonyl group. Many sugars are labelled with the suffix -ose (Campbell’s Biology, 10e, Fig. 3.4) Exploring macromolecules: carbohydrates Most common monosaccharides are made up of five (pentose) or six (hexose) carbons In aqueous solutions, most pentoses and hexoses form rings (Campbell’s Biology, 10e, Fig. 3.4) Polysaccharides are made through dehydration reactions Two monosaccharides bonded create disaccharides glucose + glucose = maltose glucose + fructose = sucrose Sucrose is the most common disaccharide and provides an energy source for many plants (Campbell’s Biology, 10e, Fig. 3.5) Polysaccharides are long chains of sugar units (Campbell’s Biology, 10e, Fig. 3.7)  Polysaccharides are long chains of sugar units Plants tend to store glucose as starch, animals tend to store glucose as glycogen Animals have enzymes to hydrolyze (break down) starch to glucose Glycogen is stored in humans primarily in the liver and muscles (Campbell’s Biology, 10e, Fig. 3.7) Polysaccharides are long chains of sugar units Cellulose – the most abundant organic compound on earth! Glucose monomers are joined differently than starch and glycogen Parallel orientation of strands help form hydrogen bonds for structural integrity Many animals (humans included) are unable to hydrolyze glucose linkages in cellulose – insoluble fiber (Campbell’s Biology, 10e, Fig. 3.7) Cellulose A panda’s diet is ~90% composed of bamboo shoots, in which the major component (~50-70%) in cellulose Pandas have not (yet) evolved the ability to digest cellulose and still retain a carnivore digestive tract Turns out, a panda’s diet macromolecules mirrors that of other carnivores instead of herbivores Some smarter species + more polysaccharide facts Certain herbivore animals contains bacteria that produce cellulase! (including cows and termites) and decomposing fungi have the enzymes to hydrolyze cellulose Chitin is another major structural polysaccharide Insect and crustacean exoskeletons Fungi cell walls Cellulose helps towels be absorbent The hydroxyl groups make carbohydrates incredibly hydrophilic Swedish dishcloths are 70% Cotton is ~90% cellulose wood cellulose and 30% cotton Lipids Lipids are dense energy-storing molecules Lipids are diverse hydrophobic (water-fearing) compounds composed largely of carbon and carboxyl hydrogen. Fats (triglycerides) consist of glycerol linked to three fatty acids. Fatty acid and glycerol linkage is accomplished via dehydration Lipids tend to end in -ol (Campbell’s Biology, 10e, Fig. 3.8)  Remember Saturated vs. Unsaturated Fats Triglyceride Carbon is happiest with Some fatty acids contain one or four bonds more double bonds, forming unsaturated fatty acids. Unsaturated fatty acids are typical of plant oils. Unsaturate d fats cause kinks Fats with the maximum number in the hydrocarbo of hydrogens are called n chains saturated fatty acids. Saturated fatty acids are found in animal fats. (Campbell’s Biology, 10e, Fig. 3.8) State of fatty acid saturation affects properties of lipids Saturated fats allow fatty acids to Kinks in unsaturated prevent fatty acids be packed together and remain from packing together and are liquid at solid at room temperature room temperature Most animal fats are saturated Most plant and fish fats are unsaturated (Campbell’s Biology, 10e, Fig. 3.8) State of fatty acid saturation affects properties of lipids  State of fatty acid saturation affects properties of lipids Partially hydrogenated oils were invented by introducing hydrogens to the double bonds of unsaturated fats These reactions, while sometimes resulted in complete hydrogenation, also introduced trans fats While increased oil shelf life, also increased risk of heart disease  Phospholipids are the major component of cell membranes Phospholipids are composed of a hydrophobic diglyceride and a negatively charged, polar phosphate group Compounds in which units have distinct polarities are phospholipid amphipathic symbol This property allows for cell membranes to retain their shape (Campbell’s Biology, 10e, Fig. 3.10) Soap’s amphipathic nature helps it clean off oil and dirt Soap’s amphipathic nature helps it clean off oil and dirt Soap’s amphipathic nature helps it clean off oil and dirt  Steroids are ring-containing lipids Steroids are lipids with a Cholesterol molecule hydrocarbon chain with the inclusion of four fused rings Cholesterol is the most common components of animal cell membranes Also acts as a precursor for making other steroids, including sex hormones (Campbell’s Biology, 10e, Fig. 3.10) Chemical structure of sex hormones estrogen testosterone Many steroids are amphipathic, with a polar end to a largely hydrophobic molecule  Cholesterol can affect membrane fluidity The polar head groups of steroids and phospholipids interact with another and can integrate into the cell membrane Inclusion of cholesterol into cell membrane’s decreases their fluidity, affecting what molecules can pass through Cholesterol can affect membrane fluidity Red blood cells (RBCs) are responsible for picking up oxygen (O2) molecules from the lung and transporting them to different tissues for energy production An increase in cholesterol content in RBC membranes leads to decreased motility and thus decrease oxygen transport