A1.1 Water

Water

A1.1.1 medium of life

water; cells originated here (in primeval soup), most life processes occur here

A1.1.1 aqueous solution

substances dissolved in water

A1.1.2 Polar Molecule - H2O

2 or more atoms bonded covalently; share electrons. When one nucleus attracted more strongly, unequal electron sharing; polar (slightly+/- charge). H2O is polar, H+, O-. Because of this, hydrogen bonds can form.

A1.1.2 Intramolecular vs inter

Intra: oxygen to hydrogen - IN
Inter: between molecules - OUT

A1.1.3 Cohesion

water to water using hydrogen bonds; xylem (pull each other up), surface tension of water (top ones attracted more strongly to the molecules beneath/beside it)

A1.1.4 Adhesion

water to other (hydrophilic) substances, by hydrogen bonds; polar. Capillary action; water sticks to sides to climb up

A1.1.5. Water as solvent

many hydrophilic molecules can dissolve in water; by forming H-bonds w water. Most chemical reactions in water; free-er movement of enzymes and substrates.

A1.1.5 Hydrophil/phob

Hydrophilic: dissolve in water: love
Hydrophobic: does not dis.: hate
Amphipathic: species where half dissolves, half doesnt…

A1.1.6 Physical Properties of Water

Buoyancy: solid floats in fluid if lower density

Viscosity: resistance to flow of fluid; cohesion; water very high

Thermal Conducivity: ability of a material to transfer heat; very large for water

Specific heat capacity: energy required to raise 1g by 1C; higher water than air; cool slowly

A1.1.6 BlackThroatedLoon and RingedSeal as examples of properties of water:

Buoyancy: seal similar density, floats easily. loon higher density than air so beat wings so doesnt “sink”

Viscosity; seal and loon need to resist when moving through; seal has it harder

Thermal Conductivity: seal needs thick skin to protect from cold

Spec.He.Cap; stable temperature and living environment

A1.1.7 Water on earth comes from?

Asteroids; and it stays here as temperatures keep the water liquid furthermore, gravity pulls it in.

A1.1.8. Extraterrestial Life

Water is medium of life, no (liquid) water=no life. Need to be in goldilocks zone; distance from star where 0<T<100 = habitable