Notes

properties of water and its uses to in living organisms

vascular tissue in plants carries water and variety of dissolved substances
xylem carries water and dissolved minerals up from the root system to the leaves of a plant
Phloem then transports dissolved sugars from the leaves to the stems, roots and flowers of a plant.

blood
- most common transport medium in animals and is largely made up of water
- traqnsport medium for red blood cells, platelets and a wide variety if dissolved molecules. the lipid portion of blood is called blood plasma
- some more common solutes in blood plasma are: glucose (blood sugar), amino acids, fibrinogen (protein involved in blood clotting), and hydrogen carbonate ions (as a means of transporting carbon dioxide)

carbohyrdrates in animals
- exist in 3 different sizes: monosaccharides, disachharides, polysachharides
- excess carbohydrates is stored as glycogen, used for energy and stored in liver and muscles

carbohydrates in plants
- fructose is found in many fruits (it makes them sweet)
- sucrose - disaccharide
cellulose - polysaccharide

disaccharides - two sugars, sucrose
monosaccharides - one sugar, glucose, galactose, fructose
polysaccharides - a lot of sugar, starch, cellulose, glycogen

Lipids
- fats, steroid, waxes and oil
- made mostly from carbon and hydrogen atoms
- ratio - 2 carbons to 1 hydrogen 2:1
- generally not soluble in water, because they are nonpolar
- they are used to store energy, protection and insulation
- they are important for parts of biological membranes and waterproof covering
- when you eat more than you burn, your body stores excess fat in adipose cells. Adipose cells get bigger or smaller depending on how much lipid is being stored at any given time. People gain weight or lose weight depending on the amount of lipids being stored in their adipose cells.
- lipids are also important for insulation, a special type of lipid called phospholipid makes up the double layer of all cell membranes.

Saturated and unsaturated
- if each carbon atom in a lipi's fatty acid chain is joined to another carbon atom by a single bond, the lipid is said to be saturated
- if there is at least one carbon-carbon double bond in a fatty acid, the fatty acid is said to be unsaturated
- lipids whose fatty acids contain more than one double bond are said to be polyunsaturated: cooking oils, canola oil, peanut oils, corn oils.

proteins
- proteins are macromolecules that contain nitrogen, carbon, hydrogen and oxygen
- polymers of molecules called amino-acids
- more than 20 different amino acids are found in nature
- all amino acids are identical in the regions where they may be joined together by covalent bonds
- some are used to form bones and muscles
- carbon, hydrogen, oxygen and nitrogen
- most enzymes are proteins; enzymes work by weakening some chemical bonds in the substrate, which is one way enzyme reduce activation energy; a change in temperature or pH can affect the enzyme or substrate, if this happens then the reaction that the enzyme would have catalyzed cannot occur
-- uses of proteins
1. chemical messengers - hormones
2. they control chemical reactions - enzymes
3. found in the cell membrane - receptor channels
4. cell structure - proteins are apart of cell structure - hair, skin, nails
5. immunity - antibodies which work against bacterias

Nucleic acids
- macromolecules containing hydrogen, oxygen, carbon, nitrogen and phosphorus
- assembled from individual monomers known as nucleotides.
- nucleotides consists of 3 parts: 5 carbon sugar, a phosphate group, a nitrogenous base.
- individual nucleotides can be joined by covalent bonds to form a polynucleotide, or nucleic acid.
- RNＡ ＆ ＤＮＡ stored and transmit hereditary, or genetic information.
- RNA - contains sugar ribose
- DNA - contains sugar dioxyribose