BIO Lecture Notes

Overview -( all living things are made up of 4 classes of large biological molecules: carbohydrate, lipids, proteins, and nucleic acids) -macromolecules: are large molecules (polymers) composed of thousands of covalently connected (monomers). -Q. Macromolecule are large molecules polymers composed of thousand of (......) connected by monomers. (Covalent bonds) -Q. In macromolecules thousands of monomers are connected by? Covalent bond Concept 5.1 -polymer: is a long molecule consisting of many repeated monomers. -( 3 of the 4 classes of life's large organic molecules are polymers: carbohydrate, proteins, nucleic acids, except lipids) -condensation reaction (dehydration reaction): occurs when 2 monomers bond together through the loss of a water molecule. -hydrolysis: a reaction that is essentially the revers of the dehydration reaction. -Q. How do polymers disassembled to monomers? By hydrolysis -Q. Occurs when 2 monomers bond together through the loss of water? A dehydration reaction. Concept 5.2 -( carbohydrates serves as fuel and building material) -carbohydrates: include sugars and the polymers of sugars. -( the simplest carbohydrates are monosaccharides (single sugars)) -(carbohydrates macromolecules are polysaccharides, polymers composed of many sugar building blocks) -sugar 1-monosaccharides: have molecular formulas that are usually multiples of CH2O. ( Glucose (C6H12O6) is the most common monosaccharide) -monosaccharides are classi ed by: ◦The location of the carbonyl group (as aldose or ketose) ◦The number of carbons in the carbon skeleton. -(monosaccharides serves as a major fuel for cells and as raw material for building molecules) -linear and ring form of Glucose: -( though often drawn as linear skeletons, in aqueous solutions many sugars form rings) -Q. Which of the following is sugar? C6H12O5, CH30,C4H6O9, i C3H6O3 -Q. What is the most common monosaccharide? Glucose 2- disaccharide: is formed when a dehydration reaction joins two monosaccharides. -( this covalent bond is called a glycosidic linkage/bond) -example of disaccharide synthesis: -Q. Lactose is an example of? Disaccharide -Q. Glucose+ galactose=? Lactose -Q. Glucose + glucose=? Maltose -Q. Glucose + fructose=? Sucrose -Q. What is the name of the bond that connects two monosaccharides? Glycosidic links 3-polysaccharide: polymers of sugars, have storage and structural roles. -( the structure and function of a polysaccharide are determined by its sugar monomers and the position of glycosidic linkages (if it is alpha or beta)) -note: in monosaccharides, they are classi ed by the location of the carbonyl group and the number of carbons. -storage polysaccharide: -starch: a storage polysaccharide of plants, consists entirely of glucose monomers -( plants store surplus starch as granules within chloroplasts and other plastids) -Glycogen: is a storage polysaccharide in animals (in liver and muscle cells) -Q. What is the function of Glycogen? Storage in animals -Q.(....) are helical? Starch -structural polysaccharide: -cellulose: is a polysaccharide which is a major component of the tough wall of plants cells. -starch and cellulose are polymers of glucose, but the glycosidic linkage di er, the di erence is based on two ring forms for glucose: alpha and beta. A storage polysaccharide of plants A major component of the tough wall of plants cells -in straight structures, H atoms on one strand can bond with OH groups on other strands. -parallel cellulose molecules held together this way are grouped into micro brils, which form strong building materials. -beta bonds in cellulose form a strong building materials for plants because of the bond between OH and H which form a straight strong bond. -ENZYMES that digest starch by hydrolyzing alpha linkage can NOT hydrolyze beta linkages in cellulose. -Therefore, cellulose in human food passes through the digestive tract as insoluble ber. -( many herbivores, from cows to termites have symbiotic relationships with microbes( bacteria digests cellulose in animals)). Concept 5.3 -(Lipids are a diverse group of hydrophobic molecules) -Lipids: they are one class of large biological molecules that do not form polymers (not a real macromolecule). -note: lipids do not form polymers but it forms 3 things. -(lipids are hydrophobic because they consist mostly of hydrocarbons, which form non-polar covalent bonds). -Q. Lipids are not able to con gure? Polymers -Q.which molecules does not form polymer? Lipid -the most biologically important lipids are fats, phospholipids, and steroids 1.fats: they are constructed from two types of smaller molecules: glycerol and fatty acids. ◦Glycerol: is a three-carbon alcohol with a hydroxyl group attached to each carbon. ◦Fatty acids: consists of a carboxyl group attached to a long carbon skeleton. -Q.Consists of a carboxyl group attached to a long carbon skeleton? Fatty acids. -In fat, 3 fatty acids are joined to glycerol by an ester linkage , creating a triacylglycerol, or triglyceride. -the structure of fats: -Fatty acids vary in length (number of carbons) and in the number and location of double bonds. -There is 2 kinds of fatty acids: • Saturated fatty acids: they have the maximum number of hydrogen atoms possible and on double bonds. ◦Fats made from saturated fatty acids are called saturated fats. ◦ They are solid at room temperature. ◦Most animal fats are saturated. • Unsaturated fatty acids: they have one or more double bonds. ◦Fats made from unsaturated fatty acids are called unsaturated fats or oils. ◦They are liquid at room temperature. ◦Plants fats and sh fats are usually unsaturated. -more information about the 2 kinds of fatty acids -( A diet rich in saturated fats may contribute to cardiovascular disease through plaque deposits). -Hydrogenation: is the process of converting unsaturated fats to saturated fats by adding hydrogen. -These trans fats may contribute more than saturated fats to cardiovascular disease. -Q.converting unsaturated fats to saturated fats by adding hydrogen?Hydrogenation -Q.which kind of fats is more at risk and contributing to cardiovascular disease? Trans fats -( hydrogenating vegetable oils also creates unsaturated fats with trans double bonds). -( a major function of fats is energy storage) -Humans and other mammals store their long-term reserves in adipose cells, adipose tissue also cushions vital organs and insulates the body. 2.phospholipids:in a phospholipids, 2 fatty acids and a phosphate group are attached to glycerol. -( the 2 fatty acids tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head), -When phospholipids are added to water, they self-assemble into a bilayer, with the hydrophobic tails pointing toward the interior. -( the structure of phospholipids results in a bilayer arrangement found in cell membranes). -( phospholipids are the major component of all cell members) 3. Steroids: are lipids characterized by a carbon skeleton consisting of four fused rings. -Cholesterol: a type of steroid, also a component in animal cell members, and a precursor from which other steroids are synthesized -( A high level of cholesterol in the blood may contribute to cardiovascular diseases).