Chapter 3 Molecules Of Cells Flashcards
What is an organic compound?
A chemical compound containing the element carbon and usually the element hydrogen.
What are isomers?
Organic compounds with the same molecular formula but different structures and, therefore, different properties.
What is hydrocarbons?
An organic compound composed only of the elements carbon and hydrogen.
What are functional groups?
A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and involved in chemical reactions.
What is hydrophilic?
“Water loving”; pertaining to polar or charged molecules (or parts of molecules) that are soluble in water.
What is hydroxyl group?
A chemical group consisting of an oxygen atom bonded to a hydrogen atom.
What is a carbonyl group?
A chemical group consisting of a carbon atom linked by a double bond to an oxygen atom.
What is a carboxyl group?
A chemical group consisting of a carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group.
What is an amino group?
A chemical group consisting of a nitrogen atom bonded to two hydrogen atoms.
What is a phosphate group?
A chemical group consisting of a phosphorus atom bonded to four oxygen atoms.
What is a methyl group?
A chemical group consisting of a carbon atom bonded to three hydrogen atoms.
What are macromolecules?
A giant molecule (a polysaccharide, protein, or nuclei acid) formed by the joining of smaller molecules, usually by a dehydration reaction.
What are polymers?
A large molecule consisting of many identical or similar monomers linked together by covalent bonds.
What is a monomer?
The subunit that serves as a building block of a polymer.
What is the dehydration reaction?
A chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule.
What is hydrolysis?
A chemical reaction that breaks bonds between two molecules by the addition of water; process by which polymers are broken down and an essential part of digestion.
What are enzymes?
A macromolecule, usually protein a, that serves as a biological catalyst, changing the rate of a chemical reaction without being consumed by the reaction.
What are carbohydrates?
Member of the class of biological molecules consisting of single monomer sugars (monosaccharides), two monomer sugars (disaccharides), and polymers (polysaccharides).
What are monosaccharides?
The simplest carbohydrate; a simple sugar with a molecular formula that is generally some multiple of CH2O. Monosaccharides are the monomers of disaccharides and polysaccharides.
Glucose
A six- carbon monosaccharide that serves as a building block for many polysaccharides and whose oxidation in cellular respirations is a major source of ATP for cells.
Disaccharide
A sugar molecule consisting of two monosaccharides linked by a dehydration reaction.
Polysaccharides
A carbohydrate polymer of many monosaccharides (sugar) linked by dehydration reactions.
Starch
A storage polysaccharide in plants; a polymer of glucose.
Glycogen
An extensively branched glucose storage polysaccharide 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.
Lipid
An organic compound consisting mainly of carbon and hydrogen atoms linked by non polar covalent bonds, making the compound mostly hydrophobic. Lipids include fats, phospholipids, and steroids and are insoluble in water.
Hydrophobic
“Water fearing”; pertaining to non polar molecules (or parts of molecules) that do not dissolve in water.
Fat
A lipid composed of three fatty acids linked to 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. EX: Olive oil, salmon.
Saturated fatty acid
A fatty acid in which all carbons in the hydrocarbon 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. EX: butter, steak.
Trans fat
An unsaturated fat linked to health risks that is formed artificially during hydrogenation of vegetable oils.
Phospholipid
A lipid made up of glycerol joined to two fatty acids and a phosphate group, giving the molecule two non-polar hydrophobic tails and a polar hydrophilic head. Phospholipids from belayers that function as biological membranes.
Steroids
A type of lipid whose carbon skeleton is in the form of four fused rings with various chemical groups attached. Examples are cholesterol, testosterone, and estrogen.
Cholesterol
A steroid that is important component of animal cell membranes and that acts as a precursor molecule for the synthesis of other steroids, such as hormones.
Anabolic steroid
A synthetic variant of the male hormone testosterone that mimics some of its effects.
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. Also refers to the separation of the two strands of the DNA double helix, caused by similar factors.
Amino acids
An organic molecule containing a carboxyl group and an amino group; serves as the monomer of proteins.
Peptide bond
The covalent bond between two amino acid units in 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
An animal that eats tertiary consumers.
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
Deoxyribonucleic acid (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.
Nucleic acid
A polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular structures and activities. The two types of nucleic acids are DNA and RNA.
RNA
A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous base adenine (A), cytosine (C), guanine (G), and uracil (U); usually single- stranded; functions as the genome of some viruses.
Nucleotides
A building block of nucleic acids, consisting of five-carbon sugar covalently bonded to a nitrogenous base and one or more phosphate groups.
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.
