Download BIOMOLECULES UNIT 3 Chemistry Review: Atoms

BIOMOLECULES UNIT 3
Chemistry Review:
Atoms- protons, neutrons, electrons
Bonding:
Ionic- electron stealing
Covalent- electron sharing
Van der Waal’s forces- attraction between positive and negatively charged ions that
cumulatively are strong, (Gecko feet), but not as strong as the other types.
Hydrogen bonds- attraction between water molecules, and other molecules
Elements- pure substances that cannot be broken down by physical or chemical means.
Compounds- pure substances formed from 2 or more elements in a particular ratio.
Ions- elements that have gained (-) or lost (+) electrons.
Isotopes- same element but with a different number of neutrons.
Chemical reactions- reactions between atoms and/or groups of atoms that rearrange into new
substances.
Macromolecules: large molecules formed joining small molecules together.
Polymers-repeating units of identical, or mostly identical units
Monomer- single unit
All bonds of macromolecules are covalent.
Organic compounds all contain carbon.
Carbohydrates- contain carbon, hydrogen and oxygen
Each carbon has one oxygen and 2 hydrogens –(CH2O)n
Each “n” is number of units in molecule.
For monosaccharides ( simple sugars), “n” = 3-7 repeats
Monosaccharides linked together- disaccharide (table sugar)
Polysaccharides-starches
Ex. Glycogen: storable energy source in liver and muscle tissue. You only store
about 1 day’s worth at a time. Liver has to be induced to release it and convert
it back to glucose.
glucose molecule
Carbohydrates in plants:
Cellulose- structural support. Humans cannot digest this as we lack cellulose.
We call cellulose “fiber”.
Carbohydrates in fungi and animals: chitin- covering on mushrooms, lobsters, shrimp
and some insect exoskeletons.
Lipids:
Mostly carbon and hydrogen.
Fats, oils, waxes (on leaf surfaces)
Energy storage.
Triglycerides-can be solid at room temp. or liquid at room temp, level is measured in blood to
determine if there is too much fat in circulation. Can cause circulatory problems.
Fat is stored in fat cells called adipose tissue.
Saturated and unsaturated fats:
Saturated- bonds all single, bound with the most hydrogens possible, solid at room
temperature.
Ex. Lard, solid Crisco
Unsaturated-double bonds, do not have maximum carbons bonded, liquid at room
temperature.
Ex. Vegetable oils, olive oil
Phospholipids: composition of the cell membrane- Hydrophobic fatty acid tails, and hydrophilic
glycerol phosphate heads.
Steroids: ex. cholesterol
Used in cell membranes, also a pre-cursor molecule for synthesis of vitamin D
Also a class of hormones synthesized by the body
Ex: estrogen, testosterone
Proteins:
Made of amino acids containing carbon, nitrogen, hydrogen, oxygen, sulfur.
Have 4 covalent bonds, and one variable “R” group.
Protein structures are 3 dimensional, and their folding patterns are unique. Denaturing a protein
destroys its pattern and its ability to function properly.
EX: snake venom- lyses red blood cells and destroys tissue that it contacts by breaking
down proteins.
Protein Functions:
15% of total body mass is protein, every function you perform requires protein.
Over 10,000 different proteins involved with structure, transport, communication, cell
growth. Also involved with speeding up chemical reactions.
Enzymes: Protein used to lower activation energy.
Are catalysts- lower activation energy and speeds up reactions.
1.
2.
3.
4.
Enzymes do not increase amount of product made
Enzymes do not get used up in reactions.
Enzymes can be re-used.
Reactions do not change the enzyme
EX: Amylase- in saliva. Breaks down amylose, a carbohydrate
Enzymes are specific for their substrate. Substrates are substances that bind to an
enzyme. They have an active site, that specifically binds the substrate. Enzymes are pH
and temperature sensitive.
Nucleic acids:
Complex macromolecules that store and transmit genetic information.
Nucleotides made of: carbon nitrogen, oxygen, phosphorous and hydrogen
Consist of:
1. Phosphate
2. Nitrogenous base
3. Ribose sugar
Also: ATP adenosine triphosphate, has 3 phosphate groups. Energy is released when the
bond between the 2nd and 3rd phosphate is broken ADP
Condensation Reactions- building monomers into polymers
Hydrolysis Reactions- breaking polymers into monomers