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.