Term
|
Definition
| an electrostatic attraction between the oxygen atom of one water molecule and the hydrogen of another |
|
|
Term
| what is bond dissociation energy |
|
Definition
| the energy it takes to break a bond |
|
|
Term
| what is the structure of the water molecule |
|
Definition
| dipolar nature, nearly a tetrahedral arrangement, hydrogen bonds between oxygen of one and hydrogen of the other (they are longer bonds and weaker) |
|
|
Term
| how does hydrogen bonding differientiate from ice to liquid water |
|
Definition
| in ice, each water molecule makes four hydrogen bonds creating a crystal lattice. by contrast, liquid water makes around 3.4 bonds |
|
|
Term
| what are common hydrogen bonds in biological systems |
|
Definition
| the hydrogen acceptor is usually oxygen or nitrogen; the hydrogen donor is another electronegative atom |
|
|
Term
| what is the best directionality of the hydrogen bond |
|
Definition
| the attraction between the partial electric charges is greatest when the bonds are in a straight line |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| give an example of a polar biomolecule |
|
Definition
| glucose, aspartate, glycerol |
|
|
Term
| give example of non-polar biomolecules |
|
Definition
|
|
Term
| give an example of an amphipathic biomolecule |
|
Definition
|
|
Term
| how does water work as a solvent |
|
Definition
| water dissolves many crystalline salts by hydrating their component ions-for example: NaCl-water molecules cluster around the Cl and Na ions |
|
|
Term
|
Definition
| crystalline compound of nonpolar solutes and water |
|
|
Term
| describe how amphipathic compounds react in aqueous solutions |
|
Definition
| long fatty acids have non-polar alkyl chains, by clustering together they minimize the non-polar surface area to the water molecules, creating a shell and stabilizing the micelle |
|
|
Term
|
Definition
| compounds that contain regions that are polar (charged) and regions that are non-polar |
|
|
Term
|
Definition
| stable structures of amphipathic compounds |
|
|
Term
| what are hydrophobic interactions |
|
Definition
| these are the forces that hold non-polar regions of the molecule together |
|
|
Term
| describe the weak attractions called van der Waals interactions |
|
Definition
| two dipoles weakly attract each other, bringing the two nuclei closer |
|
|
Term
| what is van der Waals radius |
|
Definition
| as the two nuclei draw closer together, their electron clouds begin to repel each other. van der Waals radius is a measure of how close one atom will allow another to approach |
|
|
Term
| when discussing the release of ordered water favoring the formation of subtrate-enzyme complex, what major indication shows that favoring |
|
Definition
| seperately, both enzyme and substrate force water molecules into and ordered shell. However, when a substrate binds to an enzyme, it releases water molecules, the resulting increase in entropy provides a thermodynamic push toward formation of the enzyme-subtrate complex |
|
|
Term
| what are colligative properties |
|
Definition
| solutes of all kinds alter vapor pressure, boiling point, melting point and osmotic pressure of the solvent water. |
|
|
Term
|
Definition
the term ic, is a measure of the extent to which the solute dissociates into two or more ionic species
for example: NaCl dissociates into Na and Cl so its i=2 |
|
|
Term
|
Definition
| water movement across a semipermeable membrane driven by differences in osmotic pressure |
|
|
Term
|
Definition
| when the solutions of osmolarity equal that of the cell's cytosol |
|
|
Term
|
Definition
| one with higher osmolarity than that of the cell's cytosol-the cell will shrink as water moves out |
|
|
Term
|
Definition
| one with a lower osmolarity than that of the cell's cytosol-the cell will expand as water enters and can possibly lyse |
|
|
Term
|
Definition
| commonly shown is the dissociation of water to form H+, but these "free" hydrogens are immediately hydrated to form hydronium ions |
|
|
Term
|
Definition
| short hops of protons between a series of hydrogen bonded water molecules can be extremely fast. a hydronium ion gives up a proton and a water molecule some distance away receives it to form a hydronium ion |
|
|
Term
| what is the equilibrium constant Keq |
|
Definition
| products divided by reactant |
|
|
Term
| what is the ion product of water |
|
Definition
| the concentration, at a specific temperature, of water is M-grams in 1 liter: (1000 g/L)/(18)= 55.5 |
|
|
Term
|
Definition
| when there are exactly equal concentrations of H+ and OH-, as in pure water |
|
|
Term
| how is the term pH defined through expression |
|
Definition
| pH= log 1/ [H+]=-log [H+] |
|
|
Term
|
Definition
| when the pH of the blood plasma of people with severe, uncontrolled diabetes, for example, it is often below the normal value of 7.4 |
|
|
Term
|
Definition
| in certain diseases the pH of the blood is higher than normal (both acidosis and alkalosis are life-threatening) |
|
|
Term
| what is a conjugate acid-base pair |
|
Definition
| a proton donor (conjugate acid) and its corresponding proton acceptor (base) |
|
|
Term
| what is a titration curve |
|
Definition
| a plot of pH against the amount of NaOH |
|
|
Term
| what is a significance of the titration curve that pertains to the mid point of the curve |
|
Definition
| the pH is numerically equal to the pKa |
|
|
Term
|
Definition
| these are aqueous systems that tend to resist changes in pH when small amounts of acid or base are added |
|
|
Term
| what is the buffering region |
|
Definition
| this is the flat zone of a titration curve. in this zone, a given |
|
|
Term
| what is the henderson-hasselbalch equation |
|
Definition
|
|
Term
|
Definition
| when enzymes show maximal catalytic activity at a characteristic pH |
|
|
Term
| what is a condensation reaction |
|
Definition
| an example of one is the formation of ATP from ADP and inorganic phosphate |
|
|
Term
| what is hydrolysis reaction |
|
Definition
an example is when ATP is broken apart to form ADP
hydrolysis reactions are alos responsible for the enzymatic depolymerization of proteins, carbohydrates and nucleic acids |
|
|
Term
|
Definition
| enzymes that are invariably exergonic, by producing two molecules from one, they lead to an increase in the randomness of the system |
|
|
Term
| three important features of water |
|
Definition
| it is the solvent of life, it is electronegative, and is polar |
|
|
Term
|
Definition
| a molecule or ion that can react as an acid or base |
|
|
Term
| in every drop of water there is a huge potential for |
|
Definition
| a chemical reaction since a single drop of water contains 55.5 molar (M) |
|
|
Term
| hydrogen bonds are stronger when linear or bent? |
|
Definition
|
|
Term
| in the liquid form, what doesnt allow water to form 4 bonds |
|
Definition
| thermodynamics dont allow for water to form 4 bonds but ~3.4 |
|
|
Term
| what is a dielectric constant |
|
Definition
| this indicates how able a molecule can shield an ion (better the shield, higher the constant) in other words, this means how well it can hydrate |
|
|
Term
| explain how lipids create entropy |
|
Definition
| lipids are non-polar, wiht no electric states, thus water molecules cannot react with (hydrate them), so instead of reacting with lipids, water surrounds them as a barrier-this creates order (entropy) |
|
|
Term
| when there are multiple lipids in water, how does water react to it |
|
Definition
| to be less unfavorable, water will clump the lipids together, rather than having them swim alone, this still increases entropy |
|
|
