Microbiology Chapter 2 Flashcards
Structure of the Atom
The basic structure of an atom is a nucleus, containing at least one proton and usually one or more neutrons. protons have slightly less mass than the neutrons and are positively charged. neutrons have the greatest mass and have no charge.
Outside of the nucleus contain one or more electrons. The energy levels are often called rings. The electrons have almost no mass and are negatively charged. The electrons move around the nucleus in energy levels.
Ionic Bond
type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound.
Covalent Bond
A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms.
Hydrogen Bond
a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other.
Synthesis Reaction
Synthesis reaction: A + B –> AB
Decomposition Reaction
AB –> A + B
Exchange Reaction
AB + CD –> AD + BC
Polar Covalent Bond
Occurs when atoms are shared unequally in a covalent bond. Specifically, when the difference in electronegativities of the two atoms in the bond is between 0.4 and 1.7.
What do polar bonds have to do with hydrogen bonding?
Hydrogen bonds are polar because the hydrogen and the electronegative atom do not share electrons equally.
Acid
They are chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization).
Base
The nucleobase of a nucleotide involved in base pairing, as of a DNA or RNA polymer.
Buffer
a solution containing either a weak acid and its salt or a weak base and its salt, which is resistant to changes in pH.
pH
Power of Hydrogen
quantitative measure of the acidity or basicity of aqueous or other liquid solutions.
Describe the relative amounts of H+ and OH- in an acid, base, and neutral solution. Where would each type of solution fall on the pH scale?
Acid: Below the pH of 7, high number of hydrogen concentration and low number of OH- concentration.
Neutral: pH of 7 (blood, water). Has the same amount of concentration of H+ and OH- concentrations
Base: Above pH of 7, low number of hydrogen concentration and low number of OH- concentration
For one number change in pH, there is a change in acidity by 10 times.
Organic Compound
any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen.
Inorganic Compound
any substance in which two or more chemical elements (usually other than carbon) are combined, nearly always in definite proportions.
Organic
denoting a relation between elements of something such that they fit together harmoniously as necessary parts of a whole.
Identify the building blocks of
carbohydrates.
Monosaccharides include glucose, galactose and fructose - all commonly found in food. Monosaccharides are single sugar molecules that are the building blocks for all other sugars and carbohydrates.
Give an example of a monosaccharide, a disaccharide, and a polysaccharide
monosaccharide: glucose (dextrose), fructose, galactose, xylose and ribose
Disaccharide: Sucrose (common table sugar)
Polysaccharide: Cellulose and Starch
Simple Lipid
These consist of long chain fatty acids which may be either free or combined with an alcohol by an ester linkage. They include the triglycerides (triacylglycerols) and the waxes.
Complex Lipids
Complex lipids can be defined as heterogeneous compounds made up of steroids, fats, waxes, oil, and other substances.
Heterogenous Compound
A heterogeneous mixture consists of substances which remain physically separate. It can easily be separated into its constituents by processes such as filtering, hand picking, magnetic separation etc. Example- a mixture of sand and marble.
