Exam 4 Study Guide Chapters 1-17Chapter 2Atoms, Molecules and Chemical BondsWhat is valence? What is a covalent bond? What is the difference between a polar covalent bond and a nonpolar covalent bond? Valence electrons- the number of electrons needed to fill the outermost shell. This number represents the number of covalent bonds the element must form to be stable. Covalent bond- chemical bonds formed by sharing electronsNonpolar covalent bond- 2 atoms share a pair of electrons equally; the atoms have similar or identical electronegativity.Polar covalent bond- 2 atoms share electrons unequally; one atom has a greater electronegativity, which leaves the other atom a little bit positively charged. What is a hydrogen bond? Draw two water molecules and show the hydrogen bond that might form between them.A hydrogen bond is a weak charge attraction between a partially (+)H atom of one molecule and a partially (-) atom of another molecule.Name two processes in biology where hydrogen bonding is important. Hydrogen bonds are important in both secondary and tertiary protein structure.In Secondary structure, the repeating and twisting of the peptide backbone are due to hydrogen bonding between atoms in the backbone.In Tertiary structure, the 3D shape is maintained by the weak interactions of the hydrogen bonds. Chapter 3WaterKnow the definitions of mole, molar and pH. Know how to do both pH and molarity problems.Mole= number of grams of a substance equal to its molecular weight (in Daltons)Molar= number of moles of a solute in 1 liter of solution; the concentrationpH= (-)log[H+]pH + pOH= 14[H+]+[OH-]= 10^(-14)One unit change in pH is a 10-fold change in [H+]. For example, if the pH goes from 6 to 7, there is a 10% change. BIO 101 1st EditionChapter 4Carbon and Molecular DiversityWhat is a hydrocarbon? Explain why hydrocarbons are nonpolar.A hydrocarbon is a molecule that contains only carbon and hydrogen.Hydrocarbons are nonpolar because the bonds between C and H are nonpolar covalent bonds (because their electronegativity is about the same). Name and be able to draw two functional groups that confer polarity to the carbon backbone. Chapter 5MacromoleculesBe able to name and recognize the four classes of macromolecules. Be able to identify one monomer in the macromolecule and where the bond between monomers is. Know the names of the monomers and bonds in each macromolecule. Look on Blackboard for diagrams.Carbohydrate: monomer- monosaccharide, bond- glycosidic bondProtein: monomer- amino acid, bond- peptide bondLipid: monomer- glycerol and fatty acid tail, bond- ester bondNucleic Acid: monomer- nucleotide, bond- phosphodiester bondEnzymesWhat is an enzyme? What class of macromolecules does it belong to? What does it mean to denature an enzyme? How does denaturation usually affect enzyme activity? BIO 101 1st EditionEnzyme- biological catalysts; It is classified as a protein. Denaturation means the loss of 3-D shape. If an enzyme is denatured, it usually can no longer work properly. The loss of 3-D shape leads to the loss of function. What is an allosteric enzyme? An allosteric site? An allosteric activator? An allosteric inhibitor? How do these molecules alter the activity of an allosteric enzyme?Allosteric enzymes- enzymes that have allosteric sites, and are usually complex with more than one subunitAllosteric site- the place where allosteric activity takes place in the enzyme; where its activity is alteredAllosteric activator- stabilize the active form and increases activityAllosteric inhibitor- stabilize the inactive form and decreases activityChapter 6Tour of the CellBe able to label the major organelles of a eukaryotic cell and know their function (label adiagram and also a couple of fill in the blank). Nucleus- source of genetic material (DNA) surrounded by double membrane with nuclear pores- big enough for large molecules and ribosomes to pass through.Nucleolus- place inside nucleus where ribosomes are assembled (looks like a dark spot innucleus)Cytoplasm- everything between nucleus and plasma membrane, includes semi-fluid cytoplasm and organellesRibosomes- site of protein synthesis made of RNA and proteins. Endomembrane system- complex system of interrelated membranes that are either directly connected to one another or indirectly connected by vesicles= membrane sacs which are pinched off and move from one membrane site to another. Be able to tell a plant cell from an animal cell and the reasons why.Plant cells have a cell wall, and chloroplasts, which are the site of photosynthesis, neither of which animal cells have. Chapter 7Membrane Structure and FunctionUnderstand water balance in plant and animal cells. What would happen to a red blood cell placed in pure water? What would happen to a plant cell in the same circumstance?Hypertonic- concentration of solutes dissolved in the water is greater outside of the cell. So, the concentration of H2O that is free to move is greater inside the cell. Water will diffuse out of the cell, the cell will shrink.This is a bad situation for any cell. Animal cell=crenates, Plant cell= plasmolyzed. Hypotonic- concentration of solutes dissolved in the water is greater inside the cell. So, the concentration of water that is free to move is greater outside the cell. Water will diffuse into the cell, cell will swell up. Animal cell= cell explodes (cell lysis), Plant cell=  BIO 101 1st Editionswells up, but doesn’t explode because cell wall protects it. Optimal condition for a plantcell.Isotonic- concentration of solutes outside the cell is equal to the concentration of solutes inside the cell. No net movement of water into or out of the cell. Animal cell= best condition, Plant cell= plant welts.What is similar about facilitated transport and active transport? What is different about the two processes?Facilitated Diffusion- an example of passive transport, with the diffusion of solutes across a membrane with the help of a transport protein. A solute moves down its concentration gradient.Active Transport- solute is moved against its concentration gradient. It requires a transport protein for the solute, and requires energy input from the cell.Both require a concentration gradient and a transport protein for the solute.Active transport requires energy input from the cell, and facilitated diffusion does not.What is a transport protein and what does it do? What are the two basic kinds of transport proteins (channels and carriers)