Chapter 2 Study Guide Flashcards
Define Term: Element
Chemical elements are substances that cannot be split into simpler substances by ordinary chemical means
Define Term: Atom
units of matter of all chemical elements. An element is a quantity of matter composed of atoms of the same type.
Define Term: Ion
an atom that has a positive or negative charge due to an enequal number of protons and electrons
Define Term: Molecule
when two or more atoms share electrons, the resulting combination is called a molecule
Define Term: Free Radical
an electrically charged atom or group of atoms with an unpaired electron in the outermost shell
Define Term: Compound
a substance that contains atoms of two or more different elements
Define Term: Trace Element
elements present in tiny amounts (0.4% of body mass) in the body
Name the 12 major elements in the human body:
Oxygen, Carbon, Hydrogen, Nitrogen, Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chlorine, Magnesium, Iron
Name the 4 most abundant elements in the human body:
Carbon, Oxygen, Hydrogen, Nitrogen
Name the importance of Carbon in the body:
Forms backbone chains and rings of all organic (carbon-containing) molecules: carbohydrates, lipids (fats), proteins, and nucleic acids (DNA and RNA)
Name the importance of Oxygen in the body
Part of water and many organic (carbon-containing) molecules; used to generate ATP, a molecule used by cells to temporarily store chemical energy.
Name the importance of Hydrogen in the body
Constituent of water and most organic molecules; ionized form (H+) makes body fluids more acidic.
Name the importance of Nitrogen in the body
Component of all proteins and nucleic acids
Define Term: Isotope
Isotopes are atoms of an element that have different numbers of neutrons
Define Term: Radioisotope
radioactive isotopes are unstable because their nuclei decay to form a simpler and thus more stable configuration
Define Term: Valence Electron
Electron(s) on the valence (outermost) shell
Define Term: Cation
a positively charged ion
Define Term: Anion
a negatively charged ion
Define Term: Ionic Bond
the force of attractice that holds together ions with opposite charges
Define Term: Covalent Bond
A bond where two or more atoms share electrons rather than gaining or losing them. Atoms form a covalently bonded molecule by sharing one, two, or three pairs of valence electrons. The larger the number of electron pairs shared between two atoms, the stronger the covalent bond. May form between atoms of the same element or of different elements. Most common chemical bonds in the body, and the resultant compoints form most of the body’s structures.
Define Term: Polar Covalent Bond
A covalent bond where the sharing of electrons between two atoms in unequal – the nucleius of one atoms attracts the shared electrons more strongly than the nucleus of the other atom. E.g. water, where the oxygen molecule attracts the electrons more strongly.
Define Term: Hydrogen Bond
forms when a hydrogen atoms with a partial postiive charge attracts the partial negative charge of neiboring electronegative atoms, most often larger oxygen or nitrogen atoms. Weak compared to ionic or covalent bonds.
Define Term: Inorganic
Usually lack carbon and are structurally simple. Their molecules also have only a few atoms and cannot be used by cells to perform complicated biological functions. Includes water and many salts, acids, and bases.
Define Term: Organic
always contain carbon, usually contain hydrogen, and always have covalent bonds. Most are long molecules and many are made up of long chains of carbon atoms.
How do you generate chemical reactions and cellular energy?
The making and breaking of chemical bonds.
Define Term: Polar
(chemistry) Pertaining to a compound exhibiting polarity or dipole moment, that is a compound bearing a partial positive charge on one side and a partial negative charge on the other.
Define Term: non-polar
(chemistry) Pertaining to a compound that is nonionic or does not dissociate into ions.
Examples of nonpolar compounds are fats and oil. Many nonpolar compounds are hydrophobic. They do not readily dissolve in water but they do in a nonpolar solvent.
Define Term: hydrophilic
Having an affinity for water; capable of interacting with water through hydrogen bonding; hygroscopic.
Define Term: hydrophobic
Lacking an affinity for water; insoluble in water; repelling water.
Define Term: acid
A solution is acidic if it contains a lot of hydrogen ions (H+)
Define Term: Base
A solution is basic (alkaline) if it contains a lot of hydroxide ions (OH-)
Define Term: Salt
A substance that divides in anions and cations when dissolved in water (example: sodium chloride)
Define Term: Solution
The result of a solute dissolved in a solvent
Define Term: Solvent
The medium (water) in which a solvent is dissolved to create a solution
Define Term: Solute
The compound that is dissolved in a solvent to create a solution
What are the properties of water that allow polar substances to dissolve?
Water iself is polar, so it is good at breaking bonds in polar compounts.
What does the pH scale refer to?
Acidity and Alkalinity.
What is the pH of the blood?
7.35-7.45
Acidic substances have a ____ pH value
low
Alkaline substances have a _____ pH value
High
Substances with a low pH value are considered ____.
Acidic
Substances with a high pH value are considered _____.
Alkaline (basic).
What are the four major classes of organic compounds in the body?
Carbohydrates, Lipids, Proteins, and Nucleic Acids.
Define Term: Monosaccharide. Give Examples.
Simple sugar – glucose, fructose, ribose
Define Term: Dissacharide. Give Examples.
double Sugar (made up of two monosaccharides) – Examples are sucrose, lactose, maltose
Define Term: Polysaccharide. Give Examples.
complex sugar (carbohydrate) – e.g. glycogen, starch, cellulose. Not sweet.
What is the major blood sugar?
Glucose
What is the major form of carbohydrate in the body?
Glycogen
Describe major physiological functions of triglycerides.
most plenitful lipid (fat) in the body. Provide protection, insulation, and energy (both immediate and stored). Very concentrated form of energy. Composed of a single 3-carbon glycerol molecule and 3 fatty acid molecules.
Describe the major physiological functions of phospholipids.
Major component to membranes. Amphipathic, with polar head and 2 nonpolar fatty acid tails.
Describe the major physiological functions of steriods.
Steroids have 4 rings of carbon atoms. Steroids include: sex horomone, bile salts, some vitamins, and cholesterol. Cholesterol serves as an important component of cell membranes and as starting material for sythesizing other steroids.
What is the structure of phospholipids?
The polar head is a phosphate group and glycerol molecule, and the tail is two non-polar fatty acid molecules.
What properties allow phospholipids to form bilayers in water?
the polar head in hydrophilic and forms hydrogen bonds with water, while the aminoacid tails are hydrophobic, so they cluster together to avoid the water inside and outside the cell.
What are proteins made of?
Amino acids
What are the major physiological functions of proteins?
structural, regulatory, contractile, immunological, transport, and enzymes.
What are DNA and RNA?
Nucleic Acids
Define Term: Transcription
DNA is used to make RNA, catalyzed by RNA polymerase
Define Term: Translation
In translation, RNA binds to a ribosome. The mRNA nucleotide sequence specifies the amino acid sequence of the protein to be sythesized.
What is ATP?
The major way the cell stores energy in the high energy phosphate bond.
