water

Question 1

what is water a medium for

Answer 1

metabolic reactions

Question 2

% of water in humans

Answer 2

70%

Question 3

what type of molecule is water

Answer 3

dipole - positive chared end (hyrdorgen) and a negativly charged end (oxygen) but no overall charge

Question 4

what type of bonds in water

Answer 4

hydrogen bond between + on hydrogen and - on oxygen atom

Question 5

charicteristics of hydrogen bonds

Answer 5

weak but with very large number present makes it hard to seperate

Question 6

with a positive charged ion what faces it?

Answer 6

oxygen -

Question 7

with a negativly charged ion what faces it?

Answer 7

hydrogen +

Question 8

definition of dipole

Answer 8

a polar molecule with a positive and negative charge - no overall charge

Question 9

hydrogen bond definition

Answer 9

weak attractive force between the partial positive charge of a hydrogen atom of one molecule and the patrial negative charge on another

Question 10

functions of water 8

Answer 10

solvent
metabloite
high latent heat of vaporisation
high specific heat capacity
cohesion
high surface tension
high density
transparent

ct sm hd hv hs hh

Question 11

relevance of water being transparent

Answer 11

lets aquatic plants photsynthesise

Question 12

relevance of water having high density

Answer 12

denser than air - as habitat for aquatic organisms provides support + buoyancy
ice is less dense - hydrogen bonds hold molecules further apart
ice floats on water, good insulatoor and prevents large bodies of water loosing heat and freezing - organisms beneath survive

Question 13

relevance of water having high surface tension

Answer 13

cohesion between water mols at the surface produces surface tension

in a pond - cohesion between water mol at surface produces surface tension so pond skater is supported

Question 14

relevance of water having cohesion

Answer 14

water molecules attrct each other by forming hydrogen bonds
stick together in a lattice - called cohesion
allows columns of water to be drawn up xylem in plants

hlc

Question 15

relevance of water being a solvent

Answer 15

dipoles so they attract charged particles and other polar mols
theese then dissolves in water so chemical reactions take place in solution - water acts as a transportmedium

ddc

Question 16

what is water a transport medium for in animals

Answer 16

plasma transports dissolved substances

Question 17

what is water a transport medium in plants

Answer 17

water transports minerals in xylem and sucrose and amino acids in the phloem

Question 18

relevance of water being a metabolite

Answer 18

used in many biochemical reactions as a rectant

hydrolysis+ condensation reactions

Question 19

relevance of water having high latent heat of vaporisation

Answer 19

lot of heat energy needed to change it from liquid to vapour - temp control where heat is used to vapourise water from sweat on skin

Question 20

how does water have high specific heat capacity

Answer 20

large amount of heat energy need to raise its temp because of the hydrogen bonds between water mols restricing movements, resisting increase in kinetic energy

Question 21

relevance of water having high specific heat capacity

Answer 21

prevents large fluctuations in water temp
important to keep aquatic habitats stable
allows cells to work efficiently - enzymes

Question 22

in what does non polar compounds dissolve

Answer 22

dissolve in lipids (lipid soluble)

Question 23

in what does non polar compounds NOT dissolve

Answer 23

water

Question 24

why is water used as a universal solvent

Answer 24

attracted to other water molecules and charged particles

Question 25

why is water known as the universal solvent

Answer 25

• polar
• h+ attracted to mols with - charge
• bonds in substance breaks
• substance dissolves