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64 Cards in this Set
- Front
- Back
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Does water regulate pH?
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Yes.
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What does CO2 come from?
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Partly from oxidation of food.
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What are three buffer systems in the body?
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Bicarbonate, phosphate and hemoglobin.
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Are the kidneys involved in a buffer system, and if yes, what do they excrete as a result?
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Ammonium ions and phosphate.
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Is water polar?
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Yes, very.
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Is water a good solvent?
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Yes, it is.
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What is water a good solvent for?
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It is a good solvent for polar and hydrophilic molecules.
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Does water have a high heat of evaporation?
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Yes.
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Does water have a high dielectric constant?
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Yes it does.
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What type of structure does water have? Tetrahedral
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So oxygen is positive or negative? Negative
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Which makes the hydrogens in water what?
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Partially positive.
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What is hydrogen bonding in water?
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It is due to the partial charges of hydrogen and oxygen in water that allows it to create electrostatic interactions between other waters (and other molecules that will interact)
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Does hydrogen bonding do anything important?
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This is what gives water its unique properties.
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In ice, is the water closer or farther than in liquid water?
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They are farther apart in ice, and closer in water. This is what gives them a crystalline structure.
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Does this impart a change in physical property for water as an ice?
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Yes, this is why water as ice is less dense.
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Are hydrogen bonds longer than covalent bonds?
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Yes they are.
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Do you find hydrogen bonds in nucleic acids?
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Yes you do. The two helices are held together by hydrogen bonds.
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Do you find them in sugars?
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Yes.
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Why do you find them in sugars?
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Sugars have lots of hydroxyl groups, and they interact with water, and water will help break them up.
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Is cellulose hydrogen bonded together?
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Yes
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Does this impart any physical properties to them?
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Yes, this is why they have such a great deal of strength
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What do hydrophobic forces do to water, like if you immersed water with a hydrocarbon, what happens to water?
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The hydrocarbons can't hydrogen bond, so it disrupts the structure of water.
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What is this referred to as?
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Hydrophobic interactions.
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What are amphipathic molecules?
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They are mixtures of hydrophobic and hydrophilic structures
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What is an example of an amphipathic molecule?
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Detergent or fatty acids.
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What is the structure of a detergent?
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Long hydrocarbon chains and a long polar end
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The polar end in detergent may be what?
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It may be a sulfate or have an amino end.
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How are bases held together in nucleic acids?
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They are held together by hydrophobic forces.
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Are lipids soluble in water?
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No.
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What do lipids form when needing to be transported through water then?
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Lipoproteins
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What are lipoproteins?
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They are structured with lipids in the middle and proteins on the exterior. Hydrophobic in the middle, and hydrophilic on the outside.
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What is the force between two two things electrostatically based upon?
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It is based upon the charge, the distance between them, and the factor called the dielectric constant.
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Does a vacuum or water have a higher dielectric constant?
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Water has a dielectric constant of 80. A vacuum is 1.
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What are VdW's forces?
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They are forces that occur as molecules get closer together.
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Are VdW's strong or weak?
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Weak
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Then what's the point?
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Lots of them put together makes a sizeable difference, rather than having none at all.
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What is an acid?
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Proton donor.
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What is a base?
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Proton acceptor
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HA is what?
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Acid
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A:- is what?
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Base
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What does pK equal?
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It equals the negative log of K
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Is the dissociation constant a constant?
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No, it depends on whether or not the pK is 6.8 or 7.2, and it changes as a result.
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What is an easy way to remember how kD relates to strength of an acid?
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The greater the kD, the greater the degree of dissociation, and the stronger the acid.
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What is a buffered solution?
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One that resists changes in pH.
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What is our bodies pH?
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7.4
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What does a buffer contain?
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An acid and it's conjugate base.
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Is a pure acid or salt a buffer, ever?
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No.
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When you first change pH in a titration curve, will it change quickly or slowly?
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Quickly
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When does it slow down?
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When it reaches the buffered region.
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The steepest part of the curve correlates to what in a titration curve?
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It correlates to the half-titration point.
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What is the relationship to pH and pKa?
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pH equals pKa
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What is a polyprotic acid?
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It's an acid that can donate more than one proton.
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If something has a pK of about 3, what is it probably?
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It probably is a carboxyl group.
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What is the isoelectric point?
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It's the point where it wont move an electric charge.
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What is a phosphate buffer?
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It's a very common buffer, with 3 dissociable groups.
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What are it's 3 pKa's?
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2, 6.8, and 11.8
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Is phosphate in the urine?
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Yes
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What does the HH equation allow you to do?
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Describe a buffer system, and it relates the pH of the buffer to the pK of the buffer.
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How is the pH of a buffer related to the pK of a buffer?
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They are determined by the ratio of conjugate base to the acid.
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What is the law of electroneutrality?
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It says if you have a solution, it has to be electrically neutral.
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When you have 1 millimole of acid, and you convert that acid to conjugate base, how much conjugate base do you have?
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1 millimole.
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How many acidic groups are in an amino acid?
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At least 2 acidic groups.
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What is the pK of an amino group?
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9-10
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So, if you have an acid, and are titrating it, with an amino group and a carboxyl group, what will pop off first?
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The carboxyl group, because it has a lower pK.
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