Lecture 3 What element has the highest mass percent? What element has the highest number of atoms? This is for cells. - O (because there is so much water in cells-makes 60-70% of cells) H Water is a molecule with ____________________. The differences in O and H electronegativities establishes a strong bond. - covalent bonding What We also discuss several other topics like What happened to the Galapagos finches?
Don't forget about the age old question of How do you express ordinary numbers?
Don't forget about the age old question of social work jmu
If you want to learn more check out Who was Bernard Williams?
We also discuss several other topics like What was Andrew Johnson known for?
We also discuss several other topics like What are the features of pacemaker cells?
is happening in covalent bonding? - atoms share outer shell electrons to completely fill each atoms outer shells What happens in ionic bonding? - electrons are transferred from one atom to the other to complete filled outer shells and create oppositely charged ions Metals in biological systems will be _______ and associated with _______________. - cations, anions (like Cl-) What is the angle of of the H-O-H bond in water? - 104.5 **Know how to draw dipole of water molecule** - Permanent dipoles are designated by u and are expressed in ________________. - Debye units (D) Why does water readily dissolve polar compounds? - The compounds have partial charges which the water interacts with through electrostatic interactions and H bonding. How does water dissolve salts? - Water interacts with electrostatic interactions. The water/cation and water/anion interactions are stronger than the interactions within the anhydrous salt. **be able to draw hydration shells** Water has a ___________ structure. - tetrahedral The structure of H20 is conducive to ________________, when the hydrogen atom interacts with an electronegative atom of another. H20 can associate w/ ____ other H20. - H bonding, 4 (be able to draw this structure) What is the difference between how H20 bonds in liquid water and in ice? - In liquid water, H-bonding is not complete due to irregularity of liquid water structure. In ice, a regular crystal structure is present and H-bonding is complete. This makes density less than that of liquid water. water= 3.4 H-bonds/water molecule ice= 4 H-bonds/water molecule The hydrophobic effect that causes nonpolar molecules to condense is an ______________-driven process connected to water release. - entropy **Look at diagrams in notes** An acid is _____________ while a base is a _______________. - proton donor, proton acceptor Ka is the - acid dissociation constant Many biological molecules are _________________ . - weak acids Covalent bond strength is related to differences in _______________. - atom electronegativities, distance between outer shell electrons and nucleus and nucleus charge What forms around ions when water is dissolving salts? - hydration shells of water molecules surround the ion Water can form H bonds with how many other water molecules? - 4 H bonds are _________ with a defined length of ___________ A between the oxygens. - linear; 2.8-3 Why is the hydrophobic effect favored entropically? - when a np molecule associates with another np molecule, this release the constrained water molecule that was previously ordered at the surface of the molecule. The pKa corresponds to the pH at which _____________. - half the acid is protonated