Chapter 3

Functional Groups

5 of 6 chemical groups important to chemistry of life. They affect a molecule's function by participating in chemical reactions in characteristic ways. • these groups are polar. because nitrogen or oxygen atoms exert a strong pull of shared electrons. • this often makes compounds w/ these groups Hydrophilic: Water Loving. They need a water based life.

Carbon Atom

A carbon atom has 4 or 8 electrons in it's valence shell allowing it to form 4 covalent bonds. Ex: CH4 - one of the simplest organic molecules

Glycogen

A different form of polysaccharide where animals store glucose

Trans fats

A form of fat that recent research associates with health risks. Created through hydrogenation. ▪ non-polar hydrocarbon chains are the reason fats are hydrophobic.

Dehydration Reaction

A reaction that removes a molecule of water.

Starch

A storage polysaccharide in plants, consists entirely of glucose monomers. • starch molecules coil into the helical shape and may be unbranched or branched • starch granules serve as carbohydrate "banks" from which plant cells can draw glucose for energy.

Carbon Molecules

Almost all molecules a cell makes are composed of carbon atoms bonded to one another and to atoms of other elements. Form large and complex molecules build structures necessary for life.

change in chemical groups

An extremely small difference in chemical groups can make a big difference in the form and behavior.

Enzymes

Are specialized macromolecules that speed up chemical reactions in cells

2. Carbonyl Group

Carbon atom linked by double bond to oxygen atom. If a carbonyl group is at the end of a carbon skeleton than the compound is aldehyde. If it is within a chain it is a compound called ketone.

3. Carboxyl Group

Carbon double bonded to an oxygen atom and also bonded to a hydroxyl group. The carboxyl group acts as an acid by contributing H+ to a solution and thus being ionized. (compounds w/ carboxyl groups are called carboxylic acids)

Organic Compounds

Carbon-based molecules

Making Polymers

Cells link monomers together to form polymers by a dehydration reaction.

Hydrocarbons

Compounds composed of only carbon and hydrogen. EX of hydrocarbon fuels are methane and propane.

Isomers

Compounds with the same formula but different structural arrangements. • the different shapes can result in unique properties and add greatly to the diversity of molecules. The unique properties of an organic compound depend not just on the size and shape of its carbon skeleton but also the groups of atoms that are attached to the skeleton.

5. Phosphate Group

Consists of a phosphorus atom bonded to four oxygen atoms. It usually ionized and attached to the carbon skeleton by one of it's oxygen atoms. (Organic compounds with phosphate group are called phosphates)

Saturated Fatty Acids

Have no double bonds in their hydrocarbon chain and have the max. number of hydrogen atoms. ▪ the kinks in unsaturated fatty acids prevents fats containing them from packing tightly together and solidifying

Breaking Polymers

Hydrolysis must break down macromolecules in order to make monomers available to cells. (the polymers are too big to enter cells must be broken down.)

Macromolecules

Includes carbohydrates, proteins and nucleic acids. these may be gigantic on a molecular scale. (Cells make most of the macromolecules by joining smaller molecules into chains called polymers.)

Polymers

Is a large molecule consisting of many identical or similar building blocks strung together.

Steroids

Lipids in which the carbon skeleton contains 4 fused rings.

4 main classes of molecules

Molecules have 4 main classes: carbohydrates, lipids, proteins and nucleic acids.

Carbohydrate

Refers to a class of molecules ranging from the small sugar molecules dissolved in soft drinks to large polysaccharides, such as the starch molecules in pasta • most carbohydrate monomers are monosaccharides • Glucose is an aldose and Fructose is a ketose • most sugars end in -ose • most enzymes end in -ase • Other monosaccharides may have 3 to 7 carbons. Five-carbon sugars are called pentoses, and 6-carbon sugars called hexoses - are among most common. • Many monosaccharides form rings in aqueous solutions - to form a glucose ring, carbon 1 bonds to the oxygen attached to carbon 5

Monosaccharides

Simplest carbohydrates (single unit sugars or carbohydrate monomers) (building blocks of carbohydrates) • Generally have molecular formulas that are some multiple of CH2O ◦ EX C6H12O6 // (glucose) • are the main molecules for cellular work (particularly glucose)

Monomers

The building blocks of polymers

Carbon Skeleton

The chain of carbon atoms in an organic molecule. • Can vary in length and can be branched or unbranched. • Can also include double bonds.

Hydrolysis

The digestion of polymers to make their monomers available to your cells (the reverse of a dehydration reaction, hydrolysis means to break with water.)

Cellulose

The most abundant organic compound on Earth, is a major component of the tough walls that enclose plant cells. • also a polymer of glucose The cellulose that that passes unchanged through your digestive track is called "insoluble fiber"

Hydrophobic

Water-Fearing

Cholesterol

a common compound in animal cell membrane, and animal cells also use it as a starting material for making other steroids, including sex hormones.

Chitin

another structural polysaccharide, that is used by insects and crustacean to build their exoskeleton, the hard case enclosing the animal. • found in cell walls of fungi

Polysaccharides

are macromolecules, which are polymers of hundreds to thousands of monosaccharides links together by dehydration reactions (long chains of sugar units) • function as storage molecules or as structural compounds • 3 common types are: starch, glycogen and cellulose

6. Methyl Group

consists of carbon bonded to 3 hydrogens. Compounds with the methyl group are called methylated

Disaccharide

constructed by 2 monosaccharide monomers by a dehydration reaction in cells • most common disaccharide is sucrose which is made up of a glucose monomer linked to a fructose monomer.

Lipids

diverse compounds that are grouped together because they share one trait; they do not mix well w/ water. • consist mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds. • they are hydrophobic unlike most biological molecules • they don't have huge macromolecules or polymers built from similar monomers. • vary a lot in structure and function • 3 types of lipids are fats, phospholipids and steroids

4. Amino Group

has a Nitrogen bonded to 2 hydrogens and the carbon skeleton. It acts as a base by picking up an H+ from a solution. (Organic compounds with amino group are called amines)

Unsaturated Fatty Acids

has one fewer hydrogen atom on each carbon of the double bond.

1. Hydroxyl Group

hydrogen atom bonded to oxygen atom which is bonded to carbon skeleton. (organic compounds containing hydroxyl groups are called alcohol.

Fat

is a large lipid made from 2 kinds of smaller molecules and a hydrocarbon chain, usually 16 or 18 carbon atoms in length; glycerol (an alcohol with 3 carbons each bearing a hydroxyl group) and fatty acids (consists of a carboxyl group - the functional group that gives these molecules the name fatty acid, --COOH) ▪ main function of fat is long term energy storage (a gram of fat stores more than 2x energy or a polysaccharide.) ▪ fat also known as triglyceride

Phospholipids

major component of cell membrane which cells could not live without ▪ structurally similar to fat but they contain only 2 fatty acids attached to glycerol instead of 3

Methyl Group (The 6th Group):

nonpolar, not reactive but affects the molecular shape making it a function.

Anabolic Steroids

synthetic variance of the male hormone testosterone which causes the general build up of muscle and bone mass in males during puberty and maintains masculine traits throughout life.

Diversity of Polymers

• The key to the great diversity of polymers is arrangement - variation in the sequence in which monomers are strung together • The variety of polymers accounts for the uniqueness of each organism • Monomers themselves however, are essentially universal. • Small molecules common to all organisms are ordered into large molecules, which vary from species to species and even individual to individual within each species