ch 2 - characteristics of life, properties of water

cell

smallest unit of life

homeostasis

ability to maintain

steady internal conditions when

outside conditions change

multicellular

made of two or more

cells

unicellular

made of one cell

reproduction

the process that makes more living things

organization

Living things have specialized structures with specialized functions.

growth

Living things can __________ by increasing cell size and/or increasing cell number.

development

Changing from one kind of cell to a specialized cell is _____________________.

Response to stimuli

Living things adjust and respond to changes in their internal and external environments.

Homeostasis

Living things maintain stable internal conditions.

Energy

Living things use ____________ for all the processes they perform.

Polarity

water is a polar molecule with one oxygen atom negatively charged and two hydrogen atoms positively charged.

Universal solvent

Water - due to its polarity and ability to dissolve other polar molecules

Hydrogen bonds

The weak intermolecular bonds that form between the hydrogen atom of one water molecule and the oxygen atom of another water molecule.

Solvent

Does the dissolving

Solute

Substance being dissolved

Solution

Solvent +Solute=Solution

Ex. Jello, Koolaid, and salt water

density

the ratio of the mass of a substance to the volume of the substance (The density of water is 1.0 g/cm3)

Polar Molecule

a molecule in which one side of the molecule is slightly negative and the opposite side is slightly positive

Buffer

A solution that minimizes changes in pH when extraneous acids or bases are added to the solution. Proteins and Amino acids are intracellular fluid buffers. Carbonic acid/bicarbonate is an extracellular buffer. Hemoglobin / Oxyhemoglobin is an RBC buffer.

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances (water and another substance)

Surface Tension

An invisible film at the surface of water that allows objects to walk. This is caused by the cohesive forces.

high specific heat

Water can absorb or release a tremendous amount of energy with little change in actual temperature. The ability of water to resist changes in temperature. 1 gram of water will need to absorb 4.18 Joules (amount of heat) in order to increase its temperature by 1 degree Celsius.

Acid

any compound that forms hydrogen (H+) ions in solution

Base

a compound that produces hydroxide ions (OH-) in solution

pH scale

scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution; a pH of 0 to 7 is acidic, a pH of 7 is neutral, and a pH of 7 to 14 is basic

Homeostasis

the process of maintaining the body chemical and thermal components in equilibrium. What hormone is responsible with maintaining the water homeostasis in human's body?

Expansion upon freezing

hydrogen bonds in ice are more "ordered and spaced out" making ice larger and LESS DENSE