Chapter 3 Flashcards
Valence electrons
The electrons in the outer most shell of an atom that are available for chemical bonding.
Hydrogen = 1 valence e-
Oxygen = 6 valence e-
Nitrogen = 5 valence e-
Carbon = 4 valence e-
Carbon
All organic life is based on carbon and all organic molecules contain carbon.
- It is the 4th most abundant element in the universe
- easily forms and breaks bonds with O (crucial to respiration/photosynthesis)
Isomers
Organic compounds with the same molecular formula, but different structures.
3 kinds:
1) structural
2) geometric
3) enantiomers
Structural isomers
The molecular formula for these molecules are identical, but the arrangement of the atoms is different which leads to different chemical properties.
Geometric isomers
Cis = a functional groups on the same side of the molecule
Trans = have functional groups on opposite sides of the molecule.
The difference is the location of the functional groups, but the molecular formula stays the same.
Enantiomers
Mirror images of each other
Monomers
A very small atom or molecule that serves as a building block for a polymer
(Mono =1)
Polymer
A large molecule, consisting of many identical or similar monomers.
(Poly = many)
Dehydration synthesis
The formation of larger molecules from smaller reactants, accompanied by the loss of a water molecule.
(Puts things together!)
Catalyst
A substance that increases the rate of a chemical reaction without being permanently changed.
(Should also be reusable)
Carbohydrates
- Contain carbon, hydrogen, oxygen : basic formula = CH2O
- functional groups: hydroxyl (OH) and carbonyl (C=O)
- Tend to be hydrophilic due to the OH groups
3 classes: mono/di/poly-saccharides
Function: energy-storage molecules
Monosaccharides
Single unit sugars, (aka monomers)
The basic ratio is 1:2:1 in C:H:O
(i.e. CH2O)
Ex. Glucose
(If C=O is at the end of molecule it’s a Aldehyde group, if C=O is not at the end it’s a ketone group)
Disaccharides
Two monosaccharides join together via dehydration synthesis.
Ex. Glucose + glucose - H2O (=maltose)
Polysaccharides
Could contain hundreds to thousands of monosaccharides joined together via dehydration synthesis.
4 most common:
1) Starch (plant)
2) Glycogen (animal)
3) Cellulose (plant)
4) Chitin (animal)
Starch
The simplest polysaccharide; used for an energy-storage in plants.
Made by sticking several glucoses together via dehydration synthesis.
Glycogen
A storage polysaccharide of animals; highly branched, and most often found in muscle and liver cells.
Chitin
A modified polysaccharide of animals that contains nitrogen.
It is an important structural material in the exoskeleton of insects, crabs, and lobsters.
Cellulose
The most abundant organic molecule on earth; it is the principal component of plant cell walls.
It is just a polymer of glucose, but our body cannot break it down to get the glucose out for use. (Only cows and termites can)
Proteins
Polymers made from various combinations of 20 amino acids.
Each protein contains a carbon, a carboxyl group (COOH), an amine group (NH2), and a R group
Organized by levels: primary, secondary, tertiary, quaternary.
Primary structure of protein
The sequence of amino acids in the polypeptide chain.
(In order for a protein to function, it must have the correct amino acids are arranged in a precise order)
Secondary structure of protein
Only a small portion of the protein.
The chain of amino acids either makes an alpha helix or beta pleated sheets. This is due to the hydrogen bonding of the amino acids next to each other.
Tertiary structure of proteins
Refers to the entire protein made up of chains, alpha helix, beta pleated sheets
The R groups of amino acids will interact and create covalent bonds with each other. This will shape the protein, allowing for a 3-D shape.
Quaternary structure of protein
2 or more tertiary proteins and putting them together to form a larger protein.
Denatured protein
When a protein loses its tertiary 3D shape, which is accompanied by loss of function as well.
Proteins can be denatured by acids, salts, or heat
