Chemical Level of Organization
Card Set Information
Chemical Level of Organization
Atoms basic particles
Chapter 2 A&P I; B. Carr
What is an Atom?
the smallest stable units of matter
What are atoms composed of?
What are Protons?
they are similar in size and mass with neurons and positively charged within the nucleus
What are neurons?
they are similar in size and mass with protons and neutrally charged within the nucleus
What are electrons?
They are much lighter than protons and are negatively charged. Electrons circle the nucleus and in rings
What is atomic number?
the number of protons in an atom is also the atomic number
What is the electron cloud?
the area in which the electrons travel around the nucleus at high speed, within a spherical area
What is the electron shell?
the layers in which the electrons occupy
What is an element?
is the pure substance composed of atoms of only one kind
What is an isotope?
atoms with the same element whose nuclei contain the same number of protons, but different numbers of neurons
What is the mass number?
total number of protons plus neutrons in the nucleus
What are radioisotopes?
nuclei of some isotopes are unstable and spontaneously break down and emit subatomic particles or radiation in measureable amounts
What is half-life?
the time required for half of the given amount of the isotope to decay
What is atomic weight?
roughly the average total number of protons and neutrons in the atoms of a particular atom
What is a mole?
the quantity with a weight in grams equal to that element's atomic weight
What is a valence shell?
the outer most shell of the atom
What are chemical bonds?
reactive atoms achieve stability by gaining, losing, or sharing electrons to fill their outermost energy level
What is a molecule?
refers to any chemical structure consisting of atoms held together by covalent bonds
What is a compound?
pure chemical substance made up of atoms of two or more different elements
What are covalent bonds?
atoms that share the electrons on their valence shell
What are ionic bonds?
chemical bonds created by the electrical attraction between anions and cations
What are hydrogen bonds?
a weak interaction between the hydrogen atom on one molecule and a negatively charged portion of another molecule
What is hydrophilic?
molecules that are attracted to water
What is hydrophobic?
molecules that do not readily interact with water
What is pH?
negative logarithm of the hydrogen ion concentration in moles per liter
What is neutral on the pH level?
7 is said to be neutral because there are equal number of hydrogen and hydroxide ions
What is acidic on the pH level?
below 7; there are more hydrogen ions than hydroxide ions
What is basic on the pH level?
above 7; there are more hydroxide ions than hydrogen ions
What are carbohydrates?
organic molecule that contains carbon, hydrogen, and oxygen in a ratio 1:2:1
What is glycogen?
Animal starch; has side branches consisting of chains of glucose molecules
What are lipids?
contain carbon, hydrogen, and oxygen and the carbon to hydrogen ratio is near 1:2
What are fatty acids?
long carbon chains with hydrogen atoms attached
What are eicosanoids?
lipids derived from arachidonic acid, a fatty acid that must be absorbed in the diet because it cannot be synthesized by the body
What is steroids?
large lipid molecules that share a distinctive carbon framework
What are proteins?
chains of amino acids; the most abundant organic components of the human body and in many ways the most important
What are peptide bonds?
a covalent bond reaction between a carboxyl group of one amino acid and the amino group of another
What is the primary structure of a protein?
the sequence of amino acids along its length
What is the secondary structure of a protein?
result of hydrogen bonding along the length of the polypeptide chain
What is the tertiary structure of a protein?
the coiling and folding of the polypeptide chain
What is the quaternary structure of a protein?
develops when separate polypeptide subunits interact to form a larger molecule
What are nucleic acid?
large organic molecules composed of carbon, hydrogen, oxygen, nitrogen and phosphorus