A1.1 Water

Question 1

What are the different roles of water

Answer 1

Universal solvent
metabolite
temperature buffer
maintaining biological structures

Question 2

explain waters role as a universal solvent

Answer 2

-helps multicellular organisms transport molecules around the body
-medium for chemical reactions to occur

Question 3

explain waters role as a metabolite

Answer 3

water is either a reactant or a product in metabolic reactions

Question 4

explain waters role as a temperature buffer

Answer 4

metabolic reactions are catalysed by enzymes, because enzymes are sensitive to temp, reactions can only occur within a certain temperature.
Water acts as a buffer due to high specific heat capacity

Question 5

explain waters role in maintaining biological structures

Answer 5

-contributes to the formation of cell membranes
-impacts the folding of proteins
-surrounds DNA to support the double helix

Question 6

what are atoms made up of

Answer 6

protons, neutrons and electrons

Question 7

what are ions

Answer 7

atoms that have deficit or a surplus of electrons

Question 8

what are cations

Answer 8

ions that have lost electrons and have a positive charge

Question 9

what are anions

Answer 9

ions that have gained electrons and have a negative charge

Question 10

how are atoms able to form bonds

Answer 10

electrons may be transferred to other nearby atoms or shared between atoms

Question 11

what is the purpose of bonds

Answer 11

they enable the formation of chemical compounds

Question 12

what are the different types of bonds

Answer 12

-non polar covalent bonds
- polar covalent bond
- ionic bond
-hydrogen bond

Question 13

what are non polar covalent bonds

Answer 13

they share electrons equally

Question 14

what are polar covalent bonds

Answer 14

they share electrons unequally

Question 15

what happens when one atom has more mass than the other atom in the bond

Answer 15

the electrons that are being shared will be pulled towards the heavier atom and one side will be slightly positive and one side will be slightly negative

Question 16

what is an ionic bond

Answer 16

an attraction between a positively charged ion and a negatively charged ion

Question 17

what are polar molecules

Answer 17

are molecules where one end is slightly positive while the other is slightly negative

Question 18

what are hydrogen bonds

Answer 18

an attraction between 2 polar molecules
one slightly positive and one slightly negative

Question 19

how are hydrogen bonds represented

Answer 19

with a dotted line

Question 20

what is the structure of water

Answer 20

consists of 2 hydrogen and 1 oxygen that are connected with polar covalent bonds

Question 21

how many bonds can water molecules form

Answer 21

upto 4

Question 22

what is cohesion

Answer 22

waters ability to make hydrogen bonds with itself cause water molecules to stick together

Question 23

what is surface tension

Answer 23

the property of the surface of liquid that allows it to resist an external force, due to the cohesive nature of its molecule

Question 24

what does hydrophilic mean

Answer 24

polar and charged molecules are hydrophilic because they attract water

Question 25

what is adhesion

Answer 25

the force of attraction between different types of molecules or substances, - caused by the unequal sharing of electrons in polar molecules

Question 26

what is capillary action

Answer 26

the movement of water in through a narrow space, often in opposition to external forces like gravity

Question 27

how does soil retain water

Answer 27

due to adhesion, water sticks to the soil particles

Question 28

what are solvents

Answer 28

the liquid in which a solute dissolves to create a solution

Question 29

what happens when solutes dissolve

Answer 29

their molecules separate from each other and become surrounded by water molecules this is known as a "hydrogen shell"

Question 30

what happens to polar molecules in water

Answer 30

they will dissolve because they are hydrophilic and can form hydrogen bonds

Question 31

what happens to charged ions in water

Answer 31

they will dissolve because they are electrostatically attached to water

Question 32

what happens to non polar molecules in water

Answer 32

they wont dissolve because they are insoluble and will clump together

Question 33

why is water needed for cellular metabolism

Answer 33

because it dissolves the reactants and enzymes so they can come together for reactions

Question 34

what happens to lipids during transportation

Answer 34

they are coated in phospholipids to form a structure called a "lipoprotein"

Question 35

what is a physical property

Answer 35

a measurable behaviour or characteristic of matter that exists without the matter reaction or interacting with other things

Question 36

what is buoyancy

Answer 36

an upward force applied to an object that is immersed in a fluid

Question 37

what happens if the buoyant force of the fluid is greater than the objects weight

Answer 37

the object will float

Question 38

what is buoyancy affected by

Answer 38

the density of the object

Question 39

how are birds adapted to float

Answer 39

they have hollow bones with struts to strengthen them and make them less dense

Question 40

how are bony fish adapted

Answer 40

they have a swim bladder that can fill or lose gas to change densities

Question 41

what is viscosity

Answer 41

the measure of a fluids tendency to flow - due to the amount of friction the molecules of a liquid experience as they flow over each other

Question 42

what does it mean by more viscous and less viscous

Answer 42

more viscous means theres less movement less viscous means more movement

Question 43

how do hydrogen bonds affect viscosity

Answer 43

they increase the friction making water more viscous than other substances

Question 44

how do solutes affect viscosity

Answer 44

cells and dissolved solutes increase viscosity

Question 45

what is thermal conductivity

Answer 45

the measure of a materials ability to move heat across a temperature gradient - is determined by how easily energy transfers through the material

Question 46

what is specific heat capacity

Answer 46

the quantity of heat needed to raise the temperature of a chemical per unit mass

Question 47

how is waters high specific heat capacity an advantages

Answer 47

-good for temperature regulation -body temperatures rise and fall slowly in response to external changes in temperature -creates a stable environment

Question 48

how does water compare to air

Answer 48

higher -buoyant force -viscosity -thermal conductivity -specific heat capacity

Question 49

how are ringed seals adapted to their environment

Answer 49

-is buoyant -is streamlined -insulated with blubber -due to high SHC of water, there is a stable environment

Question 50

How are black throated loons adapted to their environment

Answer 50

-buoyant -air has bad thermal conductivity so not much loss of body heat but air temperature changes more often

Question 51

where is water believed to have come from

Answer 51

from asteroids and coments which contained large amounts of water

Question 52

why can water stay on earth

Answer 52

right distance from sun and gravity stops it from escaping

Question 53

why is water a precedent to extraterrestrial life

Answer 53

because its vital to life