UNIT 1.2 BAIC CHEMISTRY Flashcards
DESCRIBE basic chemistry as it relates to the human body
DEFINE various chemical structures as they relate to the human body
DEFINE pH
- to maintain homeostasis, body fluids must maintain a specific balance of acids and bases.
- more hydrogen ions (H+) dissolved in a solution = more acidic
- more hydroxide ions (OH-) = more basic (alkaline)
Chemical reactions in the body are sensitive to small changes in acidity or alkalinity
-pH scale= 0 to 14
-pH scale is based on the number of H+ in solution.
DESCRIBE how the body maintains pH within the limits of homeostasis
Maintaining pH: Buffer Systems
While the pH of fluids from different parts of the body varies, the normal limits of each fluid are quite narrow
Blood pH is maintained between 7.35 and 7.45 by homeostatic mechanisms
Even though strong acids and bases may be taken into the body or be formed by body cells, the pH of fluids inside and outside cells remains almost constant (homeostasis).
Mass
amount of matter
Chemistry
science of the structure and interactions of matter. anything that takes up space and has mass
chemical elements total? In human body? Major ones?
- All forms of matter are made up of a limited number of building blocks
- 118 elements total
- 26 elements present in human body
- 4 major ones (O, C, H, and N) make up 96%
- 8 others contribute 3.6%; See Table 2.1
- 14 more in tiny amounts account for the remaining 0.2% of the body’s mass
- Examples: C= carbon, Na = sodium, Cl = chlorine
iodine (I) is essential for
thyroid function
Atoms
- smallest unit of an element that retains characteristics of an element
- consist of a nucleus (made of protons and neutrons)
- Overall charge of an atom is neutral
- can gain, lose or share electrons
Electrons (e-)
tiny, negatively charged particles
-Electron shells
- surrounds the nucleus
- maximum electron capacity (2 or 8)
Atomic number
- number of protons in the nucleus= atomic number
- Every element has a different number
- Ex: hydrogen = 1 proton, sodium = 11 protons, chlorine = 17 protons, etc.
Mass Number
- total number of protons plus neutrons
- Ex. sodium (11 protons and 12 neutrons) Mass number = 23
Atoms that gain electrons have what tyoe of charge
- gain = negative charge
Atoms that lose electrons
- lose = positive charge
Ions
- are electrically charged atoms
- represented by writing chemical symbol followed by the number of positive (+) or negative (-) charges
- example, Ca2+ , H+, O2-
cations
- positively charged ions
anions
negatively charged ions
Molecules
- formed when atoms share electrons
- consist of 2 or more atoms of the same (O2) or different (H20) elements
Molecular formula
- indicates the number and type of atoms that make up a molecule
- subscript indicates the number of atoms for the symbol to the left of the subscript
- ex: H20, subscript ‘2’ indicates two hydrogen atoms
- water molecule, H20, 1 atom of oxygen shares electrons w/2 atoms of hydrogen
Compounds
- substances containing 2 or more different elements
- oxygen (O2) is not a compound. only one element
Free radicals
- unstable ions or molecules that can be destructive to other nearby molecules because of unpaired electrons in their outer shells
- break important body molecules by giving up or taking an electron
- ex: superoxide (O2-); an oxygen molecule with an additional electron
Chemical bonds
- forces that bind the atoms of molecules and compounds together.
- Type of bond that will form based on the # of electrons in element’s outer shell
main types of bonds
- ionic
- covalent
- hydrogen bonds
valence shell
of electrons in element’s outer shell
octet rule
atoms combine to form molecules and share electrons to form arrangements with eight electrons in the outer shell