Ch.2 Chem in Micro

element A pure substance made of one type of atom atoms smallest and basic unit of matter neutron no charge electron negative charge proton positive charge atomic number number of protons in an atom mass number the sum of the number of neutrons and protons in an atomic nucleus valence number the number of electrons that an atom gains or loses when combining with other atoms valance shell outer shell - holds 8 electrons inner shell holds up to 2 electrons covalent bonds Bonds created by sharing electrons with other atoms to fill all outer shells polar covalent bond A covalent bond in which electrons are not shared equally non-polar covalent bonds equal sharing of electrons are covalent bonds easy to break no. hydrogen bonds very weak bond between hydrogen atom and a negatively charged atom, oxygen or nitrogen ionic bonds Formed when one or more electrons are transferred from one atom to another positive charged ion when an atom donates an electron negative charged ion when an atom receives an elctron Molecular mass The sum of the masses of all the atoms in a molecule mole molecular mass in grams dalton unit of molecular mass 1/5 chemical reactions involve the making or breaking of bonds between atoms chemical energy Energy stored in chemical bonds endergonic reaction absorb energy exergonic reactions release energy synthesis reactions 2 simple molecules combine endergonic A+B=AB anabolism synthesis of molecules in a cell Decomposition reaction two combined molecules break in two exergonic AB= A+B catabolism decomposition reactions in a cell exchange reactions synthesis and decomposition swap out elements for others organic compounds always contain carbon and hydrogen Inorganic compounds typically lack carbon usually small and structurally simple water inorganic, polar solvent, acids substance that dissociate into one or more hydrogen ions + one or more negative ion bases substance that dissociate into one or more hydroxide ions and positive ion salts substance that dissociate into cation and anions cation positive , lose electrons anion negative, gain electron pH scale low - high high = less pH low+ more pH 2/5 carbon skeleton chain of carbon atoms in an organic molecule solvent A liquid substance capable of dissolving other substances organic compound contain hydrogen, oxygen, and nitrogen, carbon functional groups responsible for most of the chemical properties of a particular organic compound macromolecules polymers consisting of many small repeating molecules how do monomer join by dehydration synthesis or condensation reaction dehydration synthesis A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule. Carboydrates serve as cell structures and cellular energy sources sugars and starches monosaccharides simple sugars with three to seven atoms isomers molecules with same chemical formula but different structure most carbohydrates examples of monosaccharides glucose and deoxyribose Disaccharide formed when two monosaccharides are joined in dehydration synthesis how can disaccharide be broken by hydrolysis plysaccharides lipids primary component of cell membrane insoluble in water what makes up lipids carbon, hydrogen, oxygen simple lipids 3/5 Fats or triglycerides Contain glycerol and fatty acids; formed by dehydration synthesis what are the two forms of simple lipids saturated fat and unsaturated fat Saturated fats no double bonds in fatty acid unsaturated fats one or more double bond in the fatty acid Cis atoms on the same side of double bond trans atoms on opposite side of double bond complex lipids cell membrane made of complex lipids phospholipids lipid with glycerol, two fatty acids, and phosphate group what make up complex lipids carbon, hydrogen, oxygen, phosphate nitrogen , sometimes sulfur are phospholipids polar or non polar they are both steroids part of membrane that keep the membrane fluid four carbon rings with a -OH group condensation reaction a chemical reaction in which two or more molecules combine to produce water or another simple molecule What are proteins made of? carbon, hydrogen, oxygen, nitrogen and sometimes sulfur why are proteins important essential in cell structure and function transport proteins that move chemicals across membrane flagella that aid in movement peptide bonds bonds between amino acids formed by dehydration synthesis primary structure in protein the amino acid sequence of the polypeptide chain secondary structure in proteins occurs when the amino acid chain folds and coils in a regular helix or pleats 4/5 tertiary structure in proteins occurs when the helix or sheet folds irregularly, forming disulfide bridges, hydrogen bonds, and Ionic bonds between amino acids quaternary structure in proteins consists of two or more polypeptides denaturation when proteins encounter hostile environments and lose their shape and function nucleic acid a complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain. in DNA adenine bonds with what thymine in DNA Cyostine bonds with Guanine deoxyribonunucleic acid (DNA) nucleic acid that contains the sugar deoxyribose double helix Ribonucleic acid RNA single strand contains ribose In RNA, adenine bonds with __________? Uracil In RNA, cytosine bounds with_____--? Guanine adenosine triphosphate ATP made of ribose, adenine, three phosphates which has more energy for a cell, ATP or ADP ATP 5/5