water test bio

why is water the medium of life?

is the medium in which most process of life occur. Dissolves nutrients necessary for life.

What are hydrogen bonds?

A weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule, is attracted to the slightly negative atom of a polar covalent bond in another molecule.

Why do hydrogen bonds form between water molecules?

negative end of the oxygen atom is attracted to the positive end of the hydrogen atom in another molecule. Opposites attract.

Water molecules

one oxygen and two hydrogens. A polar covalent bond. Oxygen is more neg then hydrogen(denser amount of electrons). Most of the negative charge comes from the oxygen. The neg Oxygen bonds with pos hydrogen because opposite charges attract.

Cohesion

the attraction of molecules for another molecule of the same kind.

effects of cohesion

allows for water to stay together, transportation of water in plants, and regulates body temperature.

How does water move through the xylem?

Tension pills on the other water molecules in the xylem tube so they all move up toward the leaf. Along with cohesion and capillary action.

Surface tension

The property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of its molecules. (stay on top and doesn’t move through the surface)

The effect of surface tension

allows objects such as plants and insects (e.g. water striders) to float on a water surface without becoming even partly submerged. Higher density = higher tension

Adhesive

attraction between disimilar molecule

The effects of adhesion.

allows water to stick to things, allows water to move through plants and animals and transport nutrients. sticks to polar or charged molecules.

capillary action

process of a liquid moving in something narrow. often against gravity. Due to cohesion, adhesion and surface tension.

effects of capillary action

allows for water to move through soil, and help water get into the roots.

Water is a universal solvent

can dissolve the most solutes out of any liquid. This is due to its polar structure.

waters role as a medium for metabolism

dissolves nutrients and molecules like sodium chloride, amino acids, glucose, and oxygen. Can’t dissolve fat.

Different types of covalent bonds

polar: unequal sharing of electrons. Non-polar: equal sharing of electrons

How does water get from the soil to the leaf?

water first evaporated from the leaf. The cohesion and evaporation in the xylem and the stoma causes tension which pulls water to the leafs exit point. The water that left the leaf is replaced in the xylem in the root system.

Adaptations off the black-throated loon

Oil that makes them waterproof, webbed feet, and a streamlined body shape.

polar

two differently charged ends due to unequal sharing. polar molecules are attracted to other polar molecules.

Buoyancy

upward force applied to a object in fluid. More force then weight: float

effects of buoyancy

buoyancy force equals the weight of the water displaced by the object. The buoyant force is upwards because there is more pressure from below than above.

viscosity

the measure of a fluids resistance to flow. more viscosity: the less it flows

effects of viscosity

waters resistance to an object moving thought it.

thermal conductivity

a material ability to move heat. How easily heat transfers through a material. high: heat moves faster

specific heat capacity

amount of heat needed to raise the temperature. High: lots of heat needed

effects of specific heat capacity

water can absorb or give off a great deal of heat without changing temperature very much. Water needs lots of heat to warm up. Water holds onto heat longer than air.

physical properties of water

high polarity, highly cohesive, high thermal conductivity, low viscosity, high specific heat, low density as a solid, and attraction to other polar molecules.

hydrophobic

tending to repel or fail to mix with water

hydrophilic

tends to attract and mix with water. polar and charged molecules.

solvent

dissolves solute

solute

is dissolved

solution

mixture of solvant and solute

salvation

the interaction of a solvent with the dissolved solute

insoluble

does not dissolve