LACL4 Flashcards
what are the water volume ratios in ICF and ECF?
ICF: 2/3
ECF: 1/3
why is water a polar molecule?
- O is more electronegative than H so attracts electrons of the covalent body towards it
- H bonding occurs (in any NOF Cl molecules)
what is meant by something being electronegative?
attracts/ gains electrons
what is meant by something being electropositive?
tending to lose electrons
is DNA parallel or anti-parallel?
anti-parallel
when is H bonding strongest?
when 3 atoms involved lie in a straight line (e.g. in DNA)
where does H bonding occur in DNA?
between bases of two strands
what type of bond is H bonding?
intermolecular force (covalent)
are molecules that form H bonds water-soluble?
yes; since they are polar
what are some examples of water soluble (hydrophillic) molecules?
- sugars
- alcohols
- aldehydes
- ketones
- compounds with N-H group
what happens to solute-solute H bonding when it dissolves in water?
replaced with energetically favourable solute-water H bonding
do O=O and O=C=O have polarity?
no (they are symmetrical and linear, even spread of electronegativity)
therefore, on their own they don’t dissolve in water
what protein carries O2 around the body?
haemoglobin protein complex
what carries/ transports CO2 around the body?
bi-carbonate (CO2 is converted to carbonic acid which dissociates and with bicarbonate diffuse into ISF and plasma where it’s used as a buffer
what happens to water molecules when hydrophobic alkyl chains are present (e.g. hydrophobic tail)?
- highly ordered H2O molecules form “cages” around hydrophobic chains
- “the hydrophobic effect”
what happens to water molecules when enzyme reacts with substrate?
water molecules are distorted (disorder); not fixed
what happens to water molecules when enzyme and substrate are NOT reacting?
water molecules are ordered and lined up around each enzyme and substrate
what is hydrophobic effect?
hydrophobic molecules arrange themselves in water so as to minimise disruption of H bonding among surrounding water molecules
- energetically stable
- water cage formed around the lipid
- ordering of water
- low entropy
what happens to water molecules when there are CLUSTERS/GROUPS of lipids?
only lipid portions at the edge of the clusters force ordering of water so fewer H2O molecules are ordered
- entropy increases (reduces SA so more water moves freely as it cannot bind)
what is an amphipathic molecule?
contain both hydrophobic and hydrophillic parts (e.g. phospholipids)
what is a liposome?
phospholipids arranged in a sphere which enclose a water droplet, especially formed to carry drugs or other substances to tissues
where are hydrophobic and hydrophillic regions found on a protein?
hydrophobic; on the inside, contains nonpolar side chains
hydrophillic; on the outside, contains polar side chains
is energy needed to fold proteins?
No; proteins fold naturally due to presence of R groups (amino acid properties)
what transports hydrophobic lipids from small intestine to other body parts?
chylomicron
what makes up chylomicrons?
- triglycerides
- phospholipids
- cholesterol
- proteins
why do fats need to be transported by chylomicrons?
they don’t dissolve in water
does water dissociate?
yes to H+ and OH-
what is the ion product equation for water?
Kw= (H)(OH) ^-14 mol/L
as Ph increases, what happens to pOH?
decreases
what do acidic solutions have in terms of H and OH ions?
high H
low OH
what do basic solutions have in terms of H and OH?
high OH
low H
pH +pOH =
14 ALWAYS
are weak acids and bases fully or partially dissociated?
partially
are strong acids and bases fully or partially dissociated?
fully
what is a proton donor and proton acceptor?
proton donor= acids
proton acceptor = bases
what is a conjugate acid-base pair?
a proton donor and corresponding proton acceptor combined
what is a buffer?
solution of a weak acid/base and one of its salts
the smaller the pKa value…
the stronger the acid
what is the purpose of a buffer?
when small amounts of acid and alkalis are added, it doesn’t change the pH by a lot
what is the Henderson-Hasselbatch equation used for?
working out the amount of weak acid or conjugate base you have in a given system
(calculating how the pH of a physiological solution responds to changes in either conjugate acid or base)
what molecule acts as a buffer in the blood?
HCO3 (bicarbonate); without it pH levels would fluctuate wildly if cellular acids enter the circulation (e.g. lactic acid)
