intro to physiology - biochemistry + water

Question 1

compound

Answer 1

contains 2 or more types of atom

Question 2

molecule

Answer 2

contains 2 or more types of atoms that are chemically combined

Question 3

covalent bonds

Answer 3

-sharing of electrons
-strong stable bond
-e.g. H2O, CO2, C6H12O6

Question 4

hydrogen bonds

Answer 4

-the attractive force between hydrogen attached to an electronegative atom of one molecule and an electronegative atom of a different molecule
-often form between water molecules

Question 5

ionic bonds

Answer 5

-donated or received electrons
-weaker more unstable bond
-atoms now charged = ions
-e.g. NaCl

Question 6

electrolytes

Answer 6

ionic compounds dissolved in water
(e.g. Na+, Cl-, K+, Ca^2+, HCO3^-, PO4^3-

Question 7

importance of electrolyes

Answer 7

-conduct electricity (muscle + nerve function)
-osmotic pressure (keeping fluids in their own compartments)
-buffers (resist pH changes in body fluids)

Question 8

why water ?

Answer 8

water is the primary substrate of living organisms

Question 9

water as a protective cushion

Answer 9

amniotic fluid of baby, cerebrospinal fluid (CSF) of brain

Question 9

water as a temperature regulator

Answer 9

water evaporates from skin (sweat) and lungs, taking heat energy to occur

Question 10

water as a lubricant

Answer 10

synovial fluid (found in cavities of synovial joints)

Question 11

water as a reactant

Answer 11

hydrolysis reactions
(e.g. starch breakdown)

Question 12

water as a solvent

Answer 12

dissolves solutes
(e.g. salts (ions) and nutrients)

Question 13

water as a transporter

Answer 13

medium for nutrient delivery and waste removal via plasma

Question 14

water as a charged dipole

Answer 14

-great at dissolving electrolytes
-the H-O bonds are polar covalent (40% ionic in nature) making water charged
-water can therefore disrupt ionic bonds to dissolve electrolytes and form shells of hydration
-great solvent, participating in many reactions, either as product or reactant

Question 15

water and its ability to form H-bonds (high latent heat of evaporation)

Answer 15

large amount of energy required to change its state (i.e. from water to gas), cools body efficiently by losing water in the form of sweat

Question 16

water and its ability to form H-bonds (high specific heat capacity of water)

Answer 16

large amount of energy required to heat water up (energy required to loosen H-bonds) - acts as a BUFFER
large changes in ext.temp. won’t cause large changes in int.temp.

Question 17

water and its ability to form H-bonds (high surface tension of water)

Answer 17

water is ‘sticky’ (H-bonds) but not too sticky, it is just the right amount to hold the cytoplasm of cells together and not too great to burst the cell membrane