Chapter 2 Flashcards
(19 cards)
What is the shape/geometry of a water molecule?
tetrahedral
How does electronegativity increase in the periodic table?
increases across and ascending within a group
Are linear or non linear bonds stronger?
linear are stronger
How do hydrogen bonds occur?
they occur between proton donors and proton acceptors
What are some of the biologically important hydrogen bonds?
- between the hydroxyl group of an alcohol and water
- between the carbonyl group of a ketone and water
- between peptide groups in polypeptides
- between complementary bases of DNA
What are the unique properties that hydrogen bonding gives water?
high boiling point, high melting point, large surface tension
What kind of reaction is the melting of ice?
spontaneous rxn
What kind of reaction is the evaporation of water?
spontaneous
How does water dissolve crystalline salts?
through hydration which is thermodynamically favorable because entropy is increased
How does water facilitate the formation of the enzyme-substrate complex?
- binding sites in enzymes and receptors are often hydrophobic
- such sites can bind hydrophobic substrates and ligands such as steroid hormones
equations for pH
pH = -log [H+]
pH + pOH = 14
equation for pKa
pKa = -logKa
equation for Ka
Ka= [H+][A-]/[HA] = Keq
When is the buffering capacity of an acid/anion system greatest?
when pH = pKa
How is the buffering region defined?
by 1 pH unit above and below the pH when the acid is 50% titrated
henderson-hasselbach equation
pH = pKa + log[A-]/[HA]
What is the range for normal blood pH?
7.35-7.45
when does acidosis occur?
when blood pH is below 7.35
when does alkalosis occur?
when pH of the blood is higher than 7.45
