BIOL 1107 1nd EditionExam # 1 Study Guide Lectures: 1 - 10Each section below includes material from the lecture, homework and textbook. Lecture 1 (August 20)Chapter 2: The Chemical Context of Life Molecular Interactions: ionic, hydrogen bonding, covalent, van der Waals (London dispersion)Ionic- the attraction between cations and anions, which have opposite charges- Two atoms are so unequal in their attraction for valence electrons that the more electronegative atom strips an electron completely away from its partner- A charged atom or molecule is called an ion- Example: The electron transfer between two atoms moves one unit of negative charge from sodium to chloride. Therefore, sodium (now 11 protons and 10 electrons) has a netelectrical charge of 1+- Positive charge = cation (mnemonic: CAT -> PAWsitive)- Negative charge = anion - Compounds formed by ionic bonds are called ionic compounds, or saltsHydrogen bond- noncovalent attraction between a hydrogen and an electronegative atom- In living cells, electronegative partners are usually oxygen and nitrogen atoms. - Hydrogen bonds b/n water molecules allow some insects to walk on waterCovalent- sharing of a pair of valence electrons by two atoms- One of the strongest bonds. - Two or more atoms held together by covalent bonds constitute a moleculeVan der Waals (London dispersion) - weak bonds that occur only when atoms and molecules arevery close together- These bonds are responsible for the ability of a gecko lizard to walk up a wall- Van der Waals interactions, hydrogen bonds, ionic bonds = weaker bondsLecture 2 (August 22)Chapter 4: Carbon and the Molecule Diversity of LifeCarbon- forms backbone of proteins, lipids and sugars in body- Enters biosphere through the action of plants, which use solar energy to transform atmospheric carbon dioxide into the molecules of life. These molecules are passed alongto animals that feed on plants. - Organic chemistry = study of carbon compounds- Forms lots of diverse structures (including long chains, branched, rings, complex rings)- Rings- glucose (carbon and oxygen major backbone)- Carbon usually completes its valence shell by sharing its 4 electrons with other atoms in covalent bonds so that 8 electrons are present- Bonds may include single bonds and double covalent bonds- C-C bonds are as strong as C-O bonds (C is the only element that bonds with its own kind about as strongly as it bonds with other elements)-Hydrocarbons- organic molecules consisting of only carbon and hydrogen- Are major components of petroleum, which is called a fossil fuel because it consists of the partially decomposed remains of organisms that lived millions of years ago- Not prevalent in living organisms; however, many cell’s organic molecules have regions consisting of only carbon and hydrogen- Ex: fats have long hydrocarbon tails attached to a non-hydrocarbon component - Neither petroleum nor fat dissolves in water (both are hydrophobic)- Why are they insoluble in water? Because the great majority of their bonds are relatively nonpolar carbon-to-hydrogen linkages- Hydrocarbons can undergo reactions that release a relatively large amount of energyIsomers- compounds that have the same numbers of atoms of the same elements but different structures and hence different properties.- Structural isomers differ in covalent arrangements of their atoms- Geometric isomers (GI) have the same covalent partnerships, but they differ in their spatial arrangements.- For GIs, differences arise from the inflexibility of double bonds. Single bonds allow atoms they join to rotate freely about the bond axis without changing compound; however, double bonds do not permit such rotationFunctional Groups- chemical groups that affect molecular function by being directly involved in chemical reactionsLecture 3 (August 25)Chapter 5: The Structure and Function of Large Biological MoleculesOrganic molecules can be very large and have thousands of functional groupsPolymer- long molecule consisting of many similar or identical building blocks linked by covalentbonds, much as a train consists of a chain of cars- Repeating units that serve as building blocks of a polymer are smaller molecules called monomers- Synthesis of polymers: condensation/dehydration reaction, monomers are connected by a reaction in which two molecules are covalently bonded to each other through loss of a water molecule- Breakdown of polymers: hydrolysis, reverse of dehydration reaction. Bonds between monomers are broken by addition of water molecules, with a hydrogen from water attaching to one monomer and a hydroxyl group attaching to adjacent monomer. - Example of hydrolysis: process of digestion; bulk of organic material in food (form of polymers) are attacked by various enzymes, which speed up hydrolysis process Carbohydrates- include both sugars and polymers of sugars- Simplest carbs = monosaccharides (aka simple sugars)- Disaccharides = double sugars (consist of two monosaccharides joined by covalent bond)- Polysaccharides = polymers composed of many sugar building blocks- Used in cell membranes- Plants: cell walls; plants store carbs for rigidity and structure- Really important in your joints (keeps it lubricated)- What does a carbohydrate look like? Can be hydrophilic/phobic; polysacch’s are hydrophobic; glucose (and other monosacch’s?) = hydrophilic because sugar can dissolvein waterMonosaccharides- generally have molecular formula of the unit CH2O- Glucose = most common monosaccharide - Trademarks of sugar (can be seen in structure of glucose): a carbonyl group and multiple hydroxyl groups- Depending on the location of carbonyl group, sugar is either aldose (aldehyde sugar) or ketose (ketone sugar)- Glucose = aldose, Fructose = ketose- Diversity of simple sugars: size of carbon skeleton (range: 3 to 7 carbons long), spatial arrangement of their parts around asymmetric carbons (carbon attached to four different atoms or groups of atoms)- Monosaccharides, particularly glucose, are major nutrients for cells- Cellular respiration = cells extract energy in series of reactions starting w/ glucose- Simple-sugar molecules- major fuel for cellular work, carbon skeletons also serve as raw material for synthesis of other types of small organic molecules, such as amino acids andfatty acidsDisaccharides- consists of two monosaccharides joined by glycosidic linkage (covalent