chapter 2 Flashcards
how much of us is made up of water
around 70% of our weight
what is a passive role
the structure (hence function) of biomolecules form in response to interaction with water
e.g. protein folding is driven to burt hydrophobic residues
what is a active role
water is a participant in many biochemical reactions
e.g. peptide bond formation releases a water molecule
what does the dipole of a water molecule influence its ability to…
-form electrostatic interactions with charged molecules
-form hydrogen bonds (including with other water molecules)
what are hydrogen bonds
they are electrostatic interations between an electronegative atom with hydrogen covalently linked (donor) to another electronegative atom with a free electron pair (acceptor)
what are two common hydrogen bonders within biomolecules
O and N
does O and N serve as acceptors or donors
both
how do hydrogen bonds compare to covalent bonds
-hydrogen bonds are about double the length
-hydrogen bonds are about only 5% the strength of a covalent bond
what is the strength of A hydrogen bond dependent on
it geometry (better lined up the stronger)
in water what molecules can donate and accept hydrogen bonds
each can donate and accept two hydrogen bonds
how many hydrogen bonds does water molecules have the potential to participate in
within water each molec has potental to partake in four hydrogen bonds with four other molecules
in water each molecule participates in an average of ___ H bonds in ______
3.4, dynamic flickering clusters
what influences the properties of water
the hydrogen bonds between water molecules confering great internal cohesions
what does water like
water
what does the large number if hydrogen bonds within water contribute to
the high heat of vaporization and specific heat capacity of water
what is the heat of vaporization
the amount of heat requires to vaporize a liquid at its boiling temp
what is the specific heat capacity
the amount of heat required to raise the temp of a substance one degree
why do H bonds make it hard for water to vaporize
because the h bonds hold onto each other so tightly
why is the specific heat capacity of water so high
because of complex mesh work of interactions between H2O molecules it allows them to absorb a lot of energy before they increase temp
what is isothermic
regulating and maintaining temp
what organisms are isothermic
most of them
what helps our bodies stay cool or isothermic
the high composition of water within our bodies, coupled with the high specific heat capacity of water
how do water molecules interact with each other in ice
water molecules participate in four hydrogen bonds with other water molecules
because ice participates in four hydrogen bonds with other molecules this leads to
ice having a lower density then liquid water