BIO 101 1st Edition Exam 4 Study Guide Chapters 1 17 Chapter 2 Atoms Molecules and Chemical Bonds What 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 electrons Nonpolar 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 3 Water Know 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 concentration pH 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 Edition Chapter 4 Carbon and Molecular Diversity What 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 5 Macromolecules Be 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 bond Protein monomer amino acid bond peptide bond Lipid monomer glycerol and fatty acid tail bond ester bond Nucleic Acid monomer nucleotide bond phosphodiester bond Enzymes What 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 Edition Enzyme 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 subunit Allosteric site the place where allosteric activity takes place in the enzyme where its activity is altered Allosteric activator stabilize the active form and increases activity Allosteric inhibitor stabilize the inactive form and decreases activity Chapter 6 Tour of the Cell Be able to label the major organelles of a eukaryotic cell and know their function label a diagram 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 in nucleus Cytoplasm everything between nucleus and plasma membrane includes semi fluid cytoplasm and organelles Ribosomes 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 7 Membrane Structure and Function Understand 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 Edition swells up but doesn t explode because cell wall protects it Optimal condition for a plant cell 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 and how are they different from one another Transport proteins are integral transmembrane proteins that move particular molecules across