Biology Chapter 3/4 Quiz

A molecule where opposite ends have opposite charges

Polar

A very weak attraction between oppositely charged molecules

Hydrogen Bond

Hydrogen bonds hold water molecules together in a phenomenon called _______

Cohesion

A measure of how hard it is to break the surface of a liquid

surface tension

The amount of heat that must be absorbed or lost for 1 gram of that substance to change its temperature by 1 degree celsius

Specific heat

Transformation of a substance from a liquid to gas

Evaporation

As liquid evaporates, its remaining surface cools, in a process called

Evaporative cooling

Why does Ice float in water?

The molecules aren't as tightly packed, making ice less dense

A liquid that is a homogenous mixture of substances

Solution

The dissolving agent of a solution

Solvent

The substance that is dissolved in a solution?

Solute

A solution where water is the solvent?

Aqueous solution

When an ionic compound is dissolved in water, each ion is surrounded by a sphere of water moles called what?

Hydration Shell

What allows large polar molecules like proteins to dissolve in water?

Their ionic and polar regions

A substance that has an affinity for water (generally polar)

Hydrophillic

A substance that DOES NOT have an affinity for water

Hydrophobic

What is molarity measuring?

Concentration

What does pH measure?

The positive or negative charges of H in a solution

Acids have a pH that is _______ 7

Under

Bases have a pH that is ______- 7

over

How do you calculate molarity?

Grams/liters

Most biological fluids have pH values in the range of?

6-8

What is a Buffer?

A substance that minimizes the change in concentrations of H and OH in a solution

_______ Refers to rain, snow, or fog with a pH lower than 5.6

Acid precipiation

Why is carbon extremely versatile?

It can form 4 bonds

What is organic chemistry?

The study of carbon compounds

Every time an atom is added to a molecule, it changes that _________ and therefore changes the _______

Shape, funciton

What are carbons most frequent partners?

hydrogen, oxygen, and nitrogen

Compounds with the same molecular formula but different structures and properties?

Isomers

Isomers that are mirror images of each other

Enantiomers

Isomers that have the same covalent arrangements but differ in spatial arrangements

Geometric isomers

What functional group includes -OH?

Hydroxyl

What functional group includes O double-bonded to C-H?

Carboxyl

What functional group includes Nitrogen?

Amino

What functional group includes CH3?

Methyl

What functional group includes Phosphorus?

Phosphate

What do functional groups do?

Components of organic molecules that are most commonly involved in chemical reactions?

Hydrocarbons

Organic molecules consisting of only carbon and hydrogen

What is a mole?

the relative formula mass of a substance in grams

How does specific heat of water affect living things?

Water can act as a buffer; High resistance to heat allows for large amounts of heat energy absorption without significant change to temperature

How does evaporation affect animals and plants?

Animals: Works as a coolant with homeostasis (dogs panting, humans sweating)

Plants: Movement of solutes from roots to leaves, allows for spread of water

Why is pH important to living things?

Very high or very low pH can change molecular shapes; shape dictates function