Chapter 2: Chemistry of Life Flashcards
major elements in the human body
- oxygen (65%)
- carbon (18%)
- hydrogen (10%)
- nitrogen (3%)
- calcium (1.5%)
- phosphorus (1%)
lesser elements in the human body
- sulfur
- potassium
- sodium
- chlorine
- magnesium
- iron
trace elements in the human body
chromium, cobalt, copper, fluorine, iodine, manganese, molybdenum, selenium, silicon, tin, vanadium, zinc
atoms
consist of:
- protons
- neutrons
- electrons
isotope
an atom of an element containing a different number of neutrons (often unstable)
valence electrons
electrons in the outer shell of an atom
molecule
a particle composed of two or more atoms united by a chemical bond
ionic bonds
one atoms transfers an electron from its outer shell to another atom
ions
electrically charged atoms
- cations (+)
- anions (-)
ionization
occurs when ionic bonds dissociate in water, forming a solution of positively and negatively charged ions thats capable of conducting electricity
electrolytes
- compounds that dissociate in water and create a solution capable of conducting electricity
- crucial for heart, nerve, and muscle function, the distribution of water in the body, and the occurrence of chemical reactions
covalent bods
- formed when two atoms share one or more pairs of electrons
- stronger than ionic bonds
hydrogen bonds
a weak attraction between a slightly positive hydrogen atom in one molecule and a slightly negative oxygen or nitrogen atom in another
potential energy
energy stored in the bonds of molecules
kinetic energy
energy in motion
metabolism
the sum of all chemical reactions in the body
catabolism
- involves breaking down complex compounds into simpler ones
- breaking of chemical bonds releases energy
- some energy is released in the form of heat
- most energy is transferred to ATP molecules
anabolism
- involves building more complex molecules from smaller subunits
- anabolic reactions require energy input
- required energy is obtained from ATP molecules
ATP
adenosine triphosphate
ADP
adenosine diphosphate
types of chemical reactions
- synthesis
- decomposition
- exchange
(all can be reversible)
inorganic molecules essential to human life
- water
- oxygen
- carbon dioxide
- acids and bases
solution
- a solute dissolved in a solvent
- can be gas, solid, or liquid
- solvent must be clear with no visible particles
- does not separate when left to stand
colloid
- usually mixtures of protein and water
- can change from a liquid to a gel
- particles are small enough to stay mixed, but large enough that the mixture is cloudy
