apbio ch 2 quiz - chem context of life (water)

unit one ch. 2 - answers on pg 42

what is cohesion

bonding between like molecules

Why can some spiders walk on water

Surface tension and having a hydrophobic exoskeleton

What type of bond is within a h20 molecule

Hydrogen bond

What are the four emergent properties of water

Cohesive behavior, moderation of temperature, expansion upon freezing, water = solvent of life

what is adhesion

bonding between unlike molecules

what is surface tension and what is it a property of

the measure of how difficult it is to break/stretch the surface of a liquid. it is a property of cohesion

what forms within hydrogen bonds

polar-covalent bonds

what is a property of adhesion

counter downwards pull of gravity in vessel walls of plants (transpiration)

hydrophilic definition

substance with an affinity for water

hydrophobic definition

substance with aversion to water (repels - eg. oil)

ice floats because

it is less dense as a solid than as a liquid

ice floating is important because

it supports life on top (polar bears) and below. if it didn’t float all bodies of water would freeze solid and life would be unsustainable

how does the term “its not the heat, its the humidity” relate to evaporative cooling

When you sweat it can’t evaporate in the humidity as easily, making it harder for your body to cool itself

what is hydrogen bonding

when a slightly negative O is attracted to a slightly positive H from a nearby molecule

how many bonds can h20 form

4

water has a high (2 answers)

specific heat and heat of vaporization

evaporative cooling is based on

waters high heat of vaporization

what cools a surface

evaporative loss of the most energetic water molecules

water is the

solvent of life

solution

liquid, homogenized mix of at least two substances

solvent

dissolving agent (liquid)

solute

disolved substance

hydrophilic example

cellulose, sugar, salt

hydrophobic example

oils, lipids

What do buffers do

Minimize concentration of h+ and oh+ ions in a solution

What is the ph of blool

7

What does carbonic acid do in the blood

Acts as a buffer and keeps it from going below 7 and above 7.8

What causes ocean acidification

When more co2 gets in water it creates carbonic acid that lowers the ocean’s ph and bleaches coral reefs