Water A1.1

Question 1

What makes water so useful for life?

Answer 1

• makes up cytoplasm (which is responsible for metabolic reactions)
• good solvent (which is able to transport things in and out of blood as plasma)

Question 2

What is the chemical make-up of a water molecule?

Answer 2

It is a polar covalent bond that has an unequal sharing of electrons (which makes the hydrogen partially positive and the oxygen partially negative)

Question 3

Cohesion

Answer 3

caused by hydrogen bonds (these hydrogen bonds are weak on their own but stronger together, intermolecular forces not actual bonds) making the water molecules to stick to one another.

Question 4

Surface tension

Answer 4

caused by cohesion of water molecules and are able to withstand the weight of very light insects. Water molecules do not bond to the oxygen molecules above the surface making the bond below stronger.
- making habitats for insects
- droplets form

Question 5

How does cohesion apply to biology?

Answer 5

the transport of water up xylem in plants despite the tension from the roots pulling the water downwards (as well as gravity)
energy is needed to break through the surface tension of water (due to the hydrogen bonds needing to be broken simultaneously) so it makes habitats for organisms like water striders and mosquitos.

Question 5

Adhesion

Answer 5

caused by the polarity of water being attracted to other polar/charged surfaces.

Question 5

How does adhesion apply to biology?

Answer 5

water is drawn up xylem vessels to keep plants moist.
also works with cohesion in xylems to work against gravity pulling it down.
plant cells exposed to air is continuously moist.

Question 5

Meniscus

Answer 5

is the curve in a tube seen when water is adhering to a polar surface. Non-polar surfaces do not have meniscus.

Question 5

Capillary action

Answer 5

water is drawn upwards through narrow tubes.

Question 6

Water as solvent

Answer 6

polar solutes dissolve in polar solvents.
makes metabolism and transport possible.

Question 6

How does water make metabolism and transport possible?

Answer 6

because cytoplasm is made of dissolved substances and the water is the solvent (aqueous solution) solutes can move around and interact .
the dissolved enzymes catalyze chemical reactions known as metabolism.
water makes the components of the reaction come together on active sites.

Question 6

Aqueous solution

Answer 6

water is the solvent of solutes. this makes the solutes able to move around and interact.

Question 7

Hydrophilic

Answer 7

water-loving
polar/charged molecule and soluble

Question 8

Hydrophobic

Answer 8

water-hating
non-polar/neutral charged molecule and repel water/not soluble, dissolve in non-polar solvents

Question 9

Water’s solvent properties help with transport in plants via:

Answer 9

mineral ions in xylem sap
sucrose and products of photosynthesis in phloem sap.

Question 10

Glucose being transported in blood

Answer 10

polar/hydrophilic/soluble
carried in blood plasma.

Question 11

Amino acids being transported in blood

Answer 11

all amino acids are soluble enough to be carried in blood plasma

Question 12

Oxygen, nitrogen, carbon, and other gases being transported in blood

Answer 12

nonpolar/hydrophobic
oxygen can dissolve in blood but not enough to provide aerobic cell respiration.
this is why hemoglobin exist in red blood cells, they have binding sites for oxygen and greatly increase the capacity of blood to transport oxygen.

Question 13

Fats + fatty acids being transported in blood

Answer 13

nonpolar/insoluble
carried in blood through lipoprotein complexes that pack the fatty acids and ships them so that fat doesn’t turn into bulky droplets. there is a single layer of phospholipid on outside and fat inside.

Question 14

Steroid hormones being transported in blood

Answer 14

nonpolar/hydrophobic
responsible for transport in blood when bound to proteins.

Question 15

Cholesterol being transported in blood

Answer 15

nonpolar/low solubility
transported around circulatory system via lipoproteins.

Question 16

Buoyancy

Answer 16

the vertical force of the liquid or gas on an object placed on it.
force = weight of object, it floats
density of object < liquid, it floats
force > gravity on object, it floats

Question 17

How does buoyancy apply to biology?

Answer 17

bony fish have air-filled swim bladder to control overall density
cyanobateria has gas vesicles to adjust how close to surface they float.

Question 18

Viscosity

Answer 18

the resistance of a fluid to flow.
the resistance is due to internal friction which is caused when one part of a liquid moves relative to another.
- the solutes cause viscosity to become higher
high viscosity = more friction = more resistance to flow

Question 19

Specific heat capacity

Answer 19

amount of energy it takes to increase temperature by 1.
lower specific heat, warms up quick, cools down quick.
water has a high specific heat because it takes a lot of energy to break hydrogen bonds.

Question 20

Specific heat capacity apply to biology

Answer 20

sweating is when the hydrogen bonds are broken and released heat from the body that has been absorbed by the water.

Question 21

Thermal conductivity

Answer 21

the rate at which heat passes through materials.
this rate depends on the collision of particles and electrons (air conducts heat less quick because particles are less close together)

Question 22

Comparing the properties of water between water and air

Answer 22

buoyancy: water > air
viscosity: water > air
specific heat capacity: water > air
thermal conductivity: water > air

Question 23

Where does the abundance of water on Earth come from?

Answer 23

asteroid collisions brought water.

Question 24

How has water retained on Earth?

Answer 24

gravity pulling the water to the Earth’s core and keeping water vapor within the Earth’s atmosphere.
temperatures low enough to condense water and the goldilock zone.

Question 25

Goldilock zone

Answer 25

habitable zones often have a lot of water but water does not equal life. planets have to be exactly not too hot not too cold to keep water having all 3 states of matter.

Question 26

Ringed seal and their buoyancy

Answer 26

floating is difficult because seals are so heavy BUT is assisted by large fat (blubber) which is less dense and makes seal more buoyant

Question 27

Ringed seal and viscosity

Answer 27

the large body weight of seals make it easier to penetrate the viscosity of water
streamlined body shape reduces drag in water
flippers help to propel self forward

Question 28

Ringed seal and thermal conductivity

Answer 28

heat from seals easily conducted to water but the blubber help to insulate against the cold water + on ice.

Question 29

Ringed seal and specific heat capacity

Answer 29

water is a stable habitat for seals because of its high SHC
on land, ice caves are used as nesting sites bc they insulate from outside temperature.

Question 30

Arctic loon and their buoyancy

Answer 30

big feathers make them buoyant in air
loon’s air sacs inflated when in water to help be more buoyant
when diving air sacs are compressed
denser and heavier bones reduce buoyancy and help dive.

Question 31

Arctic loons and viscosity

Answer 31

strong muscles in legs to dive
webbed toes for swimming and propel itself through water
torpedo-like body to move through the water easily
perfectly sized wings to help uplift in air
fast flapping of wings to help keep in air

Question 32

Arctic loons and thermal conductivity

Answer 32

dense/thick body feather to keep loon water proof/warm and insulates from cold
oil glands in skin help insulate

Question 33

Arctic loons and specific heat capacity

Answer 33

stable habitat in water due to high SHC

Question 34

Comparing seals and loons buoyancy

Answer 34

in air loons use more energy to fly than seals use to swim in water because air is less buoyant than water.

Question 35

Comparing seals and loons viscosity

Answer 35

in water, seals use more energy to push through the viscosity of water than loons have to in the air because air is less viscous than water.

Question 36

Comparing seals and loons thermal conductivity

Answer 36

water conducts the heat away the bodies of the animals submerged but air is an insulator of heat so it is easier to maintain temperature in air than in water.

Question 37

Comparing seals and loons specific heat capacity

Answer 37

water has a higher SHC than air so it is able to withstand a lot of heat before it changed as opposed to air. there this makes water a stable habitat and air an unstable habitat.