Biology Chapter 3: The Organic Molecules of Life

In animals, fats are used for

1. insulation 2. long-term energy storage.

Common disaccharides

1. maltose 2. sucrose 3. lactose

cholesterol

A lipid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids.

reagent

A substance used in a chemical reaction to detect, measure, examine, or produce other substances. 1. Benedict's Reagent is used to detect the presence of glucose-a positive reaction is yellowish brown-needs to be boiled for 5-10 minutes. 2. Bluret is a reagent for proteins-a positive reaction is purple-reacts immediately. 1: Iodine is a reagent for starch-a positive reaction is dark blue-reacts immediately.

glycerol

A three-carbon alcohol to which fatty acids are covalently bonded to make fats and oils.

phospholipids

a lipid containing a phosphate group in its molecule. The phosphate group is usually bonded to another polar functional group-is hydrophilic and water soluble-is the polar head. Also have hydrophobic (nonpolar) tails

Reactants

a substance that takes part in and undergoes change during a reaction.

Monosaccharides

have only a single sugar molecule. Known as simple sugars. Can have a carbon backbone of 3-7 carbons. Soluble in water and often form a ringlike structure

fatty acid

hydrocarbon chain often bonded to glycerol in a lipid. Has a carboxyl group at one end. May contain 16 or 18 carbon atoms per molecule. Are either saturated or unsaturated.

Monounsaturated

one double bond

biological molecules (biomolecules)

organic molecules found in cells: 1. carbohydrates 2. lipids 3. proteins (or nucleic acid)

fats

organic molecules that contain glycerol and fatty acids and is found in adipose tissue in vertebrates (such as bacon fat, lard and butter) Solid at room temperature. Contains mostly saturated fatty acids.

Emulsifier

A compound that causes oil to disperse in water.

unsaturated fatty acids

A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton.

glycogen

Animals store glucose as this. More highly branched than starch. Branching makes it easier to break down.

glucose

C6H12O6 A simple sugar that is an important source of energy. Two important isomers - fructose and galactose. Glucose is used as the prefered immediate sources of energy for nearly all types of organisms. Photosynthetic organisms manufacture glucose using energy from the sun.

nucleic acids

DNA and RNA

linking amino acids

Is used to build macromolecules of: polypeptides and proteins.

adipose tissue

Located beneath the skin and serves as a major location for the storage of fat.

proteins

Nutrients the body uses to build and maintain its cells and tissues. Amino Acids are the building blocks of protein. 1. Support 2. Metabolism 3. Transport 4.Defense 5. Regulation 6. Motion

starch

Polysaccharide. Plants store glucose as this. Exists in two forms - one is nonbranched and the other is slightly branched.

chitin

Strong but flexible nitrogenous polysaccharide found in the exoskeleton of arthropods and in the cell walls of fungi.

oils

Triglyceride, usually of plant origin, that is composed of glycerol and three fatty acids and is liquid in consistency due to many unsaturated bonds in the hydrocarbon chains of the fatty acids. (such as corn oil, olive oil, and coconut oil)

lipids

a class of macromolecules that are nonpolar and insoluble in water. Tend to be soluable in nonpolar solvants - includes fats and oils. Serve as energy storage molecules. Are critical components of biological membranes.2@2

maltrose

a disaccharide composed of two glucose subunits; sometimes known as malt sugar. the breakdown into glucose as energy is used in fermentation. A waste product is ethyl alcohol.

saturated fatty acids

a form of fatty acid that lacks double bonds between the carbon atoms

atherosclerosis

accumulation of plaque in the blood vessels sometimes causes this disease.

hydrocarbons

chains of carbon atoms that are also bonded only to hydrogen atoms.

trans fats

contain a C=C bond with the hydrogen atoms located on opposite sides of the bond.

organic molecule

contains atoms of carbon and hydrogen

diaccharide

contains two monosaccharides linked together by a dehydration synthesis reaction.

sucrose

disaccharide acquired from sugar beets and sugarcane. Used as a sweetener. breaks down into two monomers, glucose and fructose

lactose

disaccharide commonl found in milk. contains glucose molecule combined with a galactose molecule. People who are lactose intolerant are not able to break down the disaccharide lactose

inorganic molecule

does not contain a combination of carbon and hydrogen

functional group

is a specific combination of bonded atoms that always has the same chemical properties and therefore always reacts in the same way, regardless of the particular carbon skeleton to which it is attached.

carbon chain

is called its skeleton or backbone

steroids

lipids that possess a unique carbon skeleton made of four fused rings. Do not contain fatty acids, but insoluble in water.

polymer

molecules composed of many monomers; makes up macromolecules. A chain of many building blocks, like those found in cellulose, polypeptides, and nucleic acids.

polysaccharides

polymers of monosaccharides, usually glucose. Some function as short-term energy storage. Cannot easily pass through the plasma membrane and are stored within the cell. The building blocks are sugars.

enzymes

proteins that act as biological catalysts. Amylase is an enzyme catalyst that breaks down starch into sugar.

monomers

small unit that can join together with other small units to form polymers

hydrolysis reaction

splitting of a compound by the addition of water, with the H+ being incorporated in one fragment and the OH- in the other

deoxyribose

sugar in DNA. Has one less hydroxyl group than ribose.

ribose

sugar in RNA

anabolic steroids

synthetic substances that are similar to the male hormone testosterone

cellulose

the most abundant of all the carbohydrates. Plant cell walls contain cellulose. Glucose chains are held parallel to each other by hydrogen bonding to create microfibrils that are grouped into fibers. in humans serves as dietary fiber.

dehydration synthesis reaction

the reaction that is used to build a polymer from a group of monomers

triglycerides

three long fatty acids attached to the glycerol molecule. Primary use is long-term energy storage molecules

polyunsaturated

two or more double bonds

carbohydrates

used as an immediate energy source. exist as either saccharide (sugar) monomers or as polymers of saccharides. Glucose is a typical monomer. Server as fuel and energy storage as well as structure molecules in plants.