A1.1 water

existing in or persisting from the beginning or in the earliest stage of development

they slowly evolved in the oceans as cells require a complex series of biochemical reactions. ocean provided the solvent for reactions to occur.

A property of water which involves polar molecules being attracted to the water molecules and spreading out throughout the water.

• makes up the cytoplasm in all cells where cellular reactions occur • makes up the fluid inside of organelles • found between cells of multicellular organisms • permits transport of substances into and out of cells • essential to blood and many other fluids • provides a medium for aquatic life

polar covalent bond

non-polar covalent bond

they have unequal sharing of electrons. single atom of oxygen is bonded to two different hydrogen atoms. resulting in a slightly negative charge at the oxygen end and a skightly positive charge at the two hydrogen ends of the molecule.

short lived (ephemral) attractions called hydrogen bonds

when molecules of the same type are attracted to eachother (like water)

due to the layer of water molecules at the surface doesnt have any molecules above it. water molecules show a strong cohesive force to water molecules immediatley around or under it

water moves within the xylem. when water evapourates in the leaf (transpiration) the exiting water molecule is in cohesion with the water in the xylem tube that ajoins with the exit. the evapouration with corresponding cohesion creates a low pressure in this area called tension. the tension pulls the other water molecules so they all move upwards. the evaporation occurs on the stomata of the plant

an attraction between two unlike molecules due to hydrogen bonding

when water molecules are pulled up, cohesion keeps the water molecules bonded to eachother. when the column is not being pulled up then adhesion keeps the column from dropping down within the tube

soil has water in microscopic channels. water molecules adhere to the polar molecules making up the soil and other water molecules are sometimes moved by cohesion. the small root hairs od plats interlude into the water-filled spaces in and water is taken into the root.

any substance that has water as the solvent

any substance that readily dissolves in water ( water loving)

any substance that does not dissolve easily in water (water fearing)

glucose ions amino acids proteins redblood cells white blood cells suspended in plasma inorganic ions sodium potassium calcium

steroid hormones like testoserone and oestradoil passes directly through plasma and nuclear membrane as they can directly pass throgh hydrophobic layers. membrane bound proteins are hydrophobic and embed to the hydrophobic layers of a membrane

ability of an object to float

buoyant force on water is upward because theres more pressure from below than above an object placed in air has almost insignificant buoyant force

the resistance to flow in a fluid

waters resistance of a object moving through it air is less desne so its less viscous

ability of a material to conduct/ transfer heat