Water A1.1 Flashcards
What makes water so useful for life?
- makes up cytoplasm (which is responsible for metabolic reactions)
- good solvent (which is able to transport things in and out of blood as plasma)
What is the chemical make-up of a water molecule?
It is a polar covalent bond that has an unequal sharing of electrons (which makes the hydrogen partially positive and the oxygen partially negative)
Cohesion
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.
Surface tension
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
How does cohesion apply to biology?
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.
Adhesion
caused by the polarity of water being attracted to other polar/charged surfaces.
How does adhesion apply to biology?
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.
Meniscus
is the curve in a tube seen when water is adhering to a polar surface. Non-polar surfaces do not have meniscus.
Capillary action
water is drawn upwards through narrow tubes.
Water as solvent
polar solutes dissolve in polar solvents.
makes metabolism and transport possible.
How does water make metabolism and transport possible?
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.
Aqueous solution
water is the solvent of solutes. this makes the solutes able to move around and interact.
Hydrophilic
water-loving
polar/charged molecule and soluble
Hydrophobic
water-hating
non-polar/neutral charged molecule and repel water/not soluble, dissolve in non-polar solvents
Water’s solvent properties help with transport in plants via:
mineral ions in xylem sap
sucrose and products of photosynthesis in phloem sap.
Glucose being transported in blood
polar/hydrophilic/soluble
carried in blood plasma.
Amino acids being transported in blood
all amino acids are soluble enough to be carried in blood plasma
Oxygen, nitrogen, carbon, and other gases being transported in blood
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.
Fats + fatty acids being transported in blood
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.
Steroid hormones being transported in blood
nonpolar/hydrophobic
responsible for transport in blood when bound to proteins.
Cholesterol being transported in blood
nonpolar/low solubility
transported around circulatory system via lipoproteins.
Buoyancy
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
How does buoyancy apply to biology?
bony fish have air-filled swim bladder to control overall density
cyanobateria has gas vesicles to adjust how close to surface they float.
Viscosity
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
Specific heat capacity
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.
Specific heat capacity apply to biology
sweating is when the hydrogen bonds are broken and released heat from the body that has been absorbed by the water.
Thermal conductivity
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)
Comparing the properties of water between water and air
buoyancy: water > air
viscosity: water > air
specific heat capacity: water > air
thermal conductivity: water > air
Where does the abundance of water on Earth come from?
asteroid collisions brought water.
How has water retained on Earth?
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.
Goldilock zone
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.
Ringed seal and their buoyancy
floating is difficult because seals are so heavy BUT is assisted by large fat (blubber) which is less dense and makes seal more buoyant
Ringed seal and viscosity
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
Ringed seal and thermal conductivity
heat from seals easily conducted to water but the blubber help to insulate against the cold water + on ice.
Ringed seal and specific heat capacity
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.
Arctic loon and their buoyancy
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.
Arctic loons and viscosity
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
Arctic loons and thermal conductivity
dense/thick body feather to keep loon water proof/warm and insulates from cold
oil glands in skin help insulate
Arctic loons and specific heat capacity
stable habitat in water due to high SHC
Comparing seals and loons buoyancy
in air loons use more energy to fly than seals use to swim in water because air is less buoyant than water.
Comparing seals and loons viscosity
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.
Comparing seals and loons thermal conductivity
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.
Comparing seals and loons specific heat capacity
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.
