Chapter 3 Flashcards
ORGANIC COMPOUNDS
any compound of carbon and another element or a radical
ISOMERS
Organic compounds with the same molecular formula but different structures and, therefore, different properties.
HYDROCARBONS
an organic compound containing only carbon and hydrogen
FUNCTIONAL GROUPS
the branch of genomics that determines the biological function of the genes and their products
HYDROPHILIC
“Water-loving”; pertaining to polar or charged molecules (or parts of molecules) that are soluble in water.
HYDROXYL GROUP
A chemical group consisting of an oxy- gen atom bonded to a hydrogen atom.
CARBONYL GROUP
A chemical group consisting of a car- bon atom linked by a double bond to an oxygen atom.
AMINO GROUP
A chemical group consisting of a nitrogen atom bonded to two hydrogen atoms.
PHOSPHATE GROUP
A chemical group consisting of a phosphorus atom bonded to four oxygen atoms.
METHYL GROUP
A chemical group consisting of a carbon atom bonded to three hydrogen atoms.
MACRO MOLECULES
any very large complex molecule; found only in plants and animals
POLYMERS
a naturally occurring or synthetic compound consisting of large molecules made up of a linked series of repeated simple monomers
MONOMERS
a simple compound whose molecules can join together to form polymers
DEHYDRATION REACTION
A chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule.
ENZYMES
any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions
CARBOHYDRATES
an essential structural component of living cells and source of energy for animals; includes simple sugars with small molecules as well as macromolecular substances; are classified according to the number of monosaccharide groups they contain
MONOSACCHARIDES
a sugar (like sucrose or fructose) that does not hydrolyse to give other sugars; the simplest group of carbohydrates
GLUCOSE
A six-carbon monosaccharide that serves as a building block for many polysaccharides and whose oxidation in cellular respiration is a major source of ATP for cells.
DISACCHARIDE
A sugar molecule consisting of two monosaccharides linked by a dehydration reaction.
STARCH
A storage polysaccharide in plants; a polymer of glucose.
GLYCOGEN
An extensively branched glucose storage poly- saccharide found in liver and muscle cells; the animal equivalent of starch.
CELLULOSE
A structural polysaccharide of plant cell walls composed of glucose monomers. Cellulose molecules are linked by hydrogen bonds into cable-like fibrils.
CHITIN
A structural polysaccharide found in many fungal cell walls and in the exoskeletons of arthropods.
LIPIDS
an oily organic compound insoluble in water but soluble in organic solvents; essential structural component of living cells (along with proteins and carbohydrates)
HYDROPHOBIC
“Water-fearing”; pertaining to nonpo- lar molecules (or parts of molecules) that do not dissolve in water.
FAT
A lipid composed of three fatty acids linked to one glycerol molecule; a triglyceride. Most fats function as energy-storage molecules.
UNSATURATED FATTY ACID
A fatty acid that has one or more double bonds between carbons in the hydrocarbon tail and thus lacks the maximum number of hydrogen atoms. Unsaturated fats and fatty acids do not solidify at room temperature.
SATURATED FATTY ACID
A fatty acid in which all carbons in the hydrocar- bon tail are connected by single bonds and the maximum number of hydrogen atoms are attached to the carbon skeleton. Saturated fats and fatty acids solidify at room temperature.
TRANS FATS
Trans fat, also called unsaturated fatty acids or trans fatty acids, is a type of unsaturated fat that occurs in small amounts in nature, but became widely produced industrially from vegetable fats starting in the 1950s for use in margarine, snack food, packaged baked goods, and for frying fast food.
PHOSPHOLIPIDS
any of various compounds composed of fatty acids and phosphoric acid and a nitrogenous base; an important constituent of membranes
STEROIDS
One of a large group of chemical substances classified by a specific carbon structure.
CHOLESTEROL
A steroid that is an important component of animal cell membranes and that acts as a precursor molecule for the synthesis of other steroids, such as hormones.
ANABOLIC STEROIDS
any of a group of usually synthetic hormones that are derivatives of testosterone
PROTEIN
A functional biological molecule consisting of one or more polypeptides folded into a specific three-dimensional structure.
DENATURATION
A process in which a protein unravels, losing its specific structure and hence function; can be caused by changes in pH or salt concentration or by high temperature. Denaturation also refers to the separation of the two strands of the DNA double helix, caused by similar factors.
PEPTIDE BOND
The covalent bond between two amino acid units in a polypeptide, formed by a dehydration reaction.
POLYPEPTIDE
A polymer (chain) of amino acids linked by peptide bonds.
PRIMARY STRUCTURE
The first level of protein structure; the specific sequence of amino acids making up a polypeptide chain.
SECONDARY STRUCTURE
The second level of protein structure; the regular local patterns of coils or folds of a polypeptide chain.
TERTIARY STRUCTURE
The third level of protein structure; the overall three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.
QUATERNARY STRUCTURE
The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.
GENE
A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses). Most of the genes of a eukaryote are located in its chromosomal DNA; a few are carried by the DNA of mitochondria and chloroplasts.
DNA
A double-stranded helical nucleic acid molecule consisting of nucleotide monomers with deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T). Capable of replicating, DNA is an organism’s genetic material.
RNA
A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis, gene regulation, and as the genome of some viruses.
NUCLEOTIDES
a phosphoric ester of a nucleoside; the basic structural unit of nucleic acids (DNA or RNA)
DOUBLE HELIX
The form of native DNA, referring to its two adjacent polynucleotide strands interwound into a spiral shape.
GENE EXPRESSION
The process whereby genetic information flows from genes to proteins; the flow of genetic information from the genotype to the phenotype.
