Biol 1010 chpt 3 voca

Proteins are ploymers and their monomers are called amino acids.

Def: organic molecule composed of an amino group and an acid group; covalently bonds to produce peptide molecules. 41

Despite their great diveristy, organic molecules in cells, called, biological molecules, ared grouped into only four categories:

• carbohydrates, lipids, proteins and nucleic acids.
• Def: Organic molecules in cells: carbohydrates, lipids, proteins, and nucleic acids. 34

Carbohydrates are almost universally used as an immediate energy source in living things, but they also play structural roles in a variety of organisms.

Def: Class of organic compounds that includes:

• monosaccharides
• disaccharides, and
• polysaccharides;

present in food as sugars, starch and fiber. 35, 444

Cellulose is the most abundant of all the carbohydrates, which in turn are the most abundant of all the organic molecules on Earth.

Def: Polysaccharide that is the major complex carbohydrate in plant cell wall. 36

Chitin, which is found in the exoskeleton of crabs and related animals such as lobsters and insects, is also a polymer of glucose.

Def: Strong but flexible nitrogenous polysaccharide found in the exoskeleton of arthropods. 36, 320

Cholesterol is a component of an animal cell's plasma membrane, and it is the precursor of other steroids, such as the sex hormones testosterone and estrogen.

Def: One of the major lipids found in animal plasma membranes; makes the membrane impermeable to many molecules. 39, 446

It is called a dehydration reaction because the equivalent of a water molecule -- that is, an -- OH (hydroxyl group) and an -- H (hydrogen atom) is removed as the reaction occurs. Fig. 3.7 a, page 34

Def: Chemical reaction resulting in a covalent bond with the accompanying loss of a water molecule.

The protein has been denatured, and has lost its function.

Def: Loss of an enzyme's normal shape so that it no longer functions; caused by a less than optimal pH and temperature. 43

Ribose and deoxyribose, with five carbon atoms, are significant because they are found in the nucleic acids RNA and DNA, respectively.

Def: Pentrose sugar found in DNA, thaqt has one less hydroxyl group than ribose. 35

A disaccharide (di, two; saccharide, sugar) containsl two monosaccharides bonded together.

Def: Sugar that contain two units of monosaccharide; e.g. maltose. 35

DNA (deoxyridonucleic acid) and RNA (ribonucleic acid) are the nucleic acids in cells.

Def: DNA (deoxyribonucleic acid) Nucleic acid polymer produced from covalent bonding of nucleotide monomers that contain the sugar deoxyribose; the genetic material of nearly all organisms. 44

Many proteins are enzymes.

Def: Organic catalyst, usually a protein, that speeds a reaction in cells due to its particular shape. 40

Fats (such as bacon fat, lard, and butter), and oils (such as corn oil, olive oil, and coconut oil) are some well known lipids.

A fatty acid has a long chain of carbon atoms bonded only to hydrogren, with a carboxyl group at one end.

Def: Molecule that contains a hydrocarbon chain and ends with an acid group. 37

Fibrous proteins adopt a rodlike structure.

Keratin, the firous protein in hair, fingernails, horns, reptilian scales, and feathers, has many helical regions.

• Collagen, the protein that gives shape to the skin, tendons, ligaments, cartilage, and bones of animals, also contains many helical secondary structures and adopts a rodlike shape.
• Def: Structural protein with only a secondary structure (i.e., keratin, silk, collagen) 43

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

Def: Specific cluster of atoms attached to the carbon skeleton of organic molecules that enters into reactions and behaves in a predictable way.

Globular proteins have a rounded or irregular three-demensional tertiary shape. Enzymes are globular proteins, as is hemoglobin.

Def: A protein (i.e., enzymes) whose polypeptides give it a tertiary structure and a globular shape. 43

Glucose, with six carbon atoms, has a molecular formula of C₆H₁₂O_6.

Def: Six-carbon sugar that organisms degrade as a source of energy during cellular repiration. 358

Glycerol is a compound with three --OH groups. The OH groups are polar; therefore, glycerol is soluble in water.

Def: Three-carbon carbohydrate with three hydroxyl groups attached; a compenent of fats and oils. 37

Animals store glucose as glycogen, which is more highly branched.

Def: Storage polysaccharide found in animals' composed of glucose molecules joined in a linear fashion but having numberous branches. 36

Hemoglobin is a complex protein that transports oxygen.

Def: iron-containing respiratory pigment occurring in vertebrate red blood cells and in the blood plasma of some invertebrates. 40,409

During a hydrolysis reaction, an --OH group from water attached to one monomer, and an --H from water attaches to the other monomer (fig. 3.7b). In other words, water is used to break the bond holding monomers together.

Def: Splitting of a compound by the addition of water, with the H+ being incorporated in one molecule and the OH- in the other. 34

Although hydrocarbons are nonpolar and hydrophobic (non soluble in water)m glucose with sevderal -- OH groups is actually hydrophilic (soluble in water). Because cells are mainly complosed of water, the ability to interact with and be soluble in water profoundly effects the activity of organic molecules in cells.

Def: Type of molecule that interacts with water by dissolving in water and/or by forming hydrogen bonds with water molecules. 25,33

Although hydrocarbons are nonpolar and hydrophobic (non soluble in water)m glucose with sevderal -- OH groups is actually hydrophilic (soluble in water). Because cells are mainly complosed of water, the ability to interact with and be soluble in water profoundly effects the activity of organic molecules in cells.

Def: Type of molecule that does not interact with water because it is nonpolar. 25,33

Inorganic chemistry is often thought of as the chmistry of the nonliving world. and organic chemistry is the chemistry of the living world.

Def: The study of compounds not having a carbon basis, chemistry of the nonliving world. 32

Isomers are molecules that have the same number and kinds of atoms but different chemical properties because the atoms occur in different arrangements.

Def: Molecules with the same molecular fomula but a different structure, and therefore a different shape. 33

Athough molecules classified as lipids are quite varied, they have one characteristic in common: They are all insoluble in water due to their long nonpolar hydrocarbon chains and their relative lack of hydrophilic functional groups.

Def: lClass of organic compounds that tends to be soluble in nonpolar solvents; including fats and oils.

Certain biological molecules in cells are composed of a large number of the same type of subunites, called. monomers. When monomers join the result is a polymer.

Def: Small molecule that is a subunit of a polymer -- e.g. glucose is a monomer of starch. 34

Because monosaccharides have only a single sugar molecule they are called simple sugars.

Def: Simple sugar; a carbohydrate that cannot be decompsed by hydrolysis -- e.g. glucose 35

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are the nucleic acids in cells.

Def: Polymer of nucleotides; both DNA and RNA are nucleic acids.

Def: Monomer of DNA and RNA consisting of a 5-carbon sugar bounded to a nitrogenous base and a phosphate group. 44

Nucleic acids are polymers in which the monomer is called a nucleotide.

fats (such as bacon fat, lartd, and butter), and oils (such as corn oil, olive oil, and coconut oil) are some well know lipids.

Def: 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. 37

For a molecule to be organic, it must contain carbon and hydrogen; otherwise, it is an inorganic molecule.

Def: Molecule that always contains carbon and hydrogen, and often contains oxygen as well; organic molecules are associated with living things. 32

Inorganic chemistry is often thought of as the chemistry of the nonliving world, and organic chemistry is the chemistry of the living world.

Def: The study of carbon compounds; chemistry of the living world.

A peptide is two or more amino acids covalently bonded together, and a polypeptide is a chain of many amino acids joined by peptide bonds.

Def: Two or more amino acids joined together by covalent bonding. 42

• The resulting covalent bond between twoi amino acids is called a peptide bond.
• Def: A type of covalent bond that joins two amino acids. 41

• Phospholipids, as implied by their name, contain a phosphate group. Essentially, a phospholipid is constructed loike a triglyceride, except that in place of the thirst fatty acid to glycerol, there isa a charged phosphate group.
• Def: Molecule that forms the phospholipid bilayer of plasma membranes; has a polar hdrophilic head bonded to two nonpolar hydrophobic tails.

When monomers join the result is a polymer. Just as a train increases in length when boxcars are hitched together one by one, so a polymer gets longer as monomers bond to one another.

• Def: Macromolecule consisting of covalently bonded monomers; for example, a polypeptide is a polymer of monomers called amino acids. 34

A peptide os two or more amino acids covalently bonded together, and a polypeptide is a chain of many amino acids joined by peptide bonds. Polypeptides containing more than 100 amino acids are generally referred to as proteins, but a protein may contain one or more polypeptide chains.

Def: Polymer of many amino acids linked by a peptide bonds.

Polysaccharides are polymers of monosaccharides. Some types of polysaccharides function as short-term energy storage molecules because they are much larger than a sugar and relatively insoluable. Polysaccharides cannot easily pass through the plasma membrance are kept (stored) within the cell.

Def: Polymert of many amino acids linked by peptide bonds. 42

Proteins are of primary importance in the structure and function of cells. Here are some of their many functions:

• Support
• metabolism
• Transport
• Defense
• Regulation
• Motion

Def: Molecule consisting of one or more polypeptides; a macronutrient in the diet that is digested to amino acids used by cells to synthesize cellular proteins. 40, 446

Ribose and deoxyribose, with five carbon atoms, are significant because they are found in the nucleic acids RNA and DNA, respectively.

Def: Pentose suguar found in RNA. 35

• DNA (deoxyridonucleic acid) and RNA (ribonucleic acid) are the nucleic acids in cells.
• Def: Nucleic acid produced from covalent bonding of nucleotide monomers that contain the sugar ribose; occurs in three major forms: messenger RNA, ribosomal RNA and transfer RNA, 44, 166

Saturated fatty acids have NO double bonds between the carbon atoms. (fig 3.13b) (butter)

Def: Fatty acid molecule that lacks double bonds between the carbons of its hydrocarbon chain. The chain bears the maximum number of hydrogens possible.

• Plants store glucose as starch. The cells of a potato contain granules where starch resides during winter until energy is needed for growth in the spring.
• Def: Storage polysaccharide found in plants that is composed of glucose molecules joined in a linear fashion with few side chains. 36

Steroids are lipids that process a unique carbon skeleton made of four fused rings. Unlike other lipids, steroids do NOT contain fatty acids, but they are similar to other lipds because they are insoluble in water. Steroids are also very diverse. Each type of steroid differs primarioly in the types of functional . groups attached to the carbon skeleton. (fig. 3.15)

Def: Type of lipid molecule having a complex of four carbon rings -- e.g. cholesterol, estrogen, progesterone, and testosterone. 38

trans fats contain fatty acids that have been partially hdrogenated to make them ore saturated, and thus more solid. (fig 3.13c) Trans fats are often found in processed foods- margarine, baked goods, and fried foods in particular.

Because three long fatty acids are attached to each glycerold molecule, fats and oils are called triglycerides and pack a log of energy in one molecule. thus it is logical that fats and oils are the body's primary long-term energy storage molecules.

Def: Neutral fat composed of gycerol and three fatty acids. 37, 445

Unsaturated fatty acids have double bonds in the carbon chain wherever the number of hydrogens is less than two per carbon atom. The chain bends.

Def: Fatty acid molecule that has one or more double bonds between the carbons of its hydrocarbon chain. the chain bears fewer hydrogens than the manimum number possible. 38 (fig 3.13 a) Canola oil