Module 2 Flashcards
(41 cards)
2 characteristics of water
- most abundant
- passive + active roles
passive role
forms structure in response to interaction with water
active role
water is a participant
O2 structure
- more electronegative than H+
- partial negative charge
does water have a permanent or non-permanent dipole?
permanent because of its electronegativity
what charge does Hydrogen have
partial positive
what do dipoles influence (2)
- the ability to form electronegative interactions with charged molecules
- the ability to form hydrogen bonds
what are amphipathic molecules?
have both polar and non-polar portions
what are hydrogen bonds
electrostatic interactions between an electronegative atom with H+ covalently bonded to another electronegative atom with free electron pair (O2 or N2)
Are Anti-parallel or parallel beta sheets more stable?
more stable than parallel sheets due to better geometry of H+ bonds
unique abilities of O2/N2
can serve as electron donors & acceptors
what is a H+ bond donor?
electronegatively charged atom that has H+ covalently attached
How many H+ bonds can H2O molecules form?
4 H+ bonds (2 acceptors, 2 donors)
advantage of H+ bonds between H2O molecules
confer great internal cohesion
how many H+ bonds does liquid H2O have?
3-4
what does electronegative mean?
an atom’s tendency to attract electrons to itself
what does permanent dipole mean?
uneven distribution of charge
what does Van der waals forces mean?
interaction between permanent + induced dipoles
when is attraction at its max in van der waals forces?
when 2 atoms are separated by the sum of radii
what is the hydrophobic effect?
polar groups interact with water and non-polar regions away from water
non-polar compounds dissolve ( ) in water
poorly
non-polar side chains
form away from water
polar side chains
on surface, away from water
how do strong acids/bases dissociate in water?
they fully dissociate in water
