Flashcards in Life at the cellular level 4 Deck (10):
what are the general properties of water? (6)
- bathes cells (interstitial fluid)
- dissipates heat
- acts as a solvent
- participates in chemical reactions
- can hydrogen bond
- can stabilse enzyme substarte reactions (though H-bonding)
what is the hydrophobic effect?
hydrophobic molecules aim to minimise disruption to hydrogen bonding by allowing cages of water to form around hydrophobic molecules
what is a chylomicron?
a complex that transports hydrophobic lipids in the bloodstream
what is Kw?
a constant that represnts the extent to which water dissociates
(= 1x10^ -14)
what is Ka?
the tendency for an acid to lose its proton
what is the equation for Ka?
Ka = [H+][A-] / [HA]
how do buffers work?
- if extra acid is added it reacts with the A- to remove the extra hydrogen ions helping to maintain the pH
- if a base is added the OH- reacts witht he H+ ions and so more HA dissociates to replace the H+ ions lost maintaining the pH
- this can only occur until all of the A- or HA has reacted
what is the henderson-hasselbach equation?
pH = pKa + log ([A-]/[HA])
name some common buffers present in the body
- phosphate buffers: H2PO4 --> H+ + HPO4(^2-)
- bicarbonate buffers: H2CO3 --> H+ + HCO3(^1-)