Studied by 5 people
a chemical element is...
the simplest form of matter to have unique chemical properties
How many naturally occurring elements are there on earth? How many play normal roles in humans?
91 24
What elements take up 98.5% of the body's weight?
Oxygen (O) 65% Carbon (C) 18% Hydrogen (H) 10% Nitrogen (N) 3% Calcium (Ca) 1.5% Phosphors (P) 1%
What elements take up 0.8% of body's weight
Sulfur (S) .25% Potassium (K) .20% Sodium (Na) .15% Chlorine (Cl) .15% Magnesium (Mg) .05% Iron (Fe) .006%
What elements take up 0.7% of body's weight
Chromium (Cr) Cobalt (Co) Copper (Cu) Fluorine (F) Iodine (I) Manganese (Mn) Molybdenum (Mo) Selenium (Se) Silicon (Si) Tin (Sn) Vanadium (V) Zinc (Zn)
What are the elements that take up 0.7% of weight known as
trace elements
Define minerals
substances extracted from the soil by plants and passed up the food chain to humans and other organisms
How much weight do Minerals count as in the body
4%
What minerals count as three quarters of the 4%
Calcium (Ca) and Phosphorus (P)
What other minerals constitute the weight for the 4%
Chlorine (Cl) Magnesium (Mg) Potassium (K) Sodium (Na) Sulfur (S)
What do minerals contribute significantly to
body structure
each chemical is composed of a unique type of...
atom
what are the electrons called that are in the outermost shell
valence electrons
what function does a valence electron have
determines the formation of chemical bonds
All elements have two or more varieties called...
isotopes
What makes elements differ from each other
number of neutrons
What is the decay of unstable isotopes by giving off radiation called
radioactivity
what are the unstable isotopes called
radioisotopes
radioactivity is a form of
ionizing radiation (UV radiation, X-rays)
Ionizing radiation can be damaging because
it can cause cancer, birth defects, or immediate death
Ionizing radiation can be beneficial in controlled settings like
radiography, PET scans, and cancer radiation therapy
Define ions
charged particles with unequal number of protons and electrons
What is the process of ionization
electrons transferring from one to the other and turn both of them into ions
anion
a negatively charged ion
cation
a positively charged ion
Ions with ___ charges are strongly ____ to each other and unite in ____ bonds.
opposite
attracted
ionic
Define Electrolytes
A salt that ionizes in water and produces a solution that conducts electricity
What is electrolytes important for
chemical reactivity, osmotic effects, and electrical effects
______ balance is on of the most important considerations in patient care
Electrolyte
Define free radicals
A particle derived from an atom or molecule, having an unpaired electron that makes it highly reactive and destructive to cells;
What do antioxidants do to free radicals
neutralize and limit their destruction
How do molecules form
two or more atoms are united by a chemical bond
Define compound
molecules composed of two or more different elements
How are molecules represented
molecular formulae
Define isomers
molecules with identical formulae but different arrangements
ionic bond
a chemical bond in which one atom loses an electron to form a positive ion and the other atom gains an electron to form a negative ion
describe ionic bond
weak easily dissociate (break up)
Covalent bond
a chemical bond that involves sharing a pair of electrons between atoms in a molecule
nonpolar covalent bond
electrons spend equal time around each nucleus
polar covalent bond
shared electrons spend more time orbiting one nucleus. They lend their negative charge where the spend most time
hydrogen bond
A weak attraction between a slightly positive hydrogen atom on one molecule and a slightly negative oxygen or nitrogen atom on another molecule
single covalent
sharing one electron pair
double covalent
sharing two electron pairs
what easily disrupts an ionic bond
water
What is the strongest chemical bond
nonpolar covalent
What is the weakest chemical bond
hydrogen bond
What percent of our bodies is water
50% to 75%
What is the universal solvent
water
substances that dissolve are
solutes
hydrophilic
having a strong affinity for water; tending to dissolve in, mix with, or be wetted by water
hydrophobic
lacking affinity for water; tending to repel and not absorb water; tending not to dissolve in or mix with or be wetted by water
Functions of water
Universal solvent Adhesion Cohesion thermal stability chemical reactivity
adhesion
tendency to cling to other substances
cohesion
attraction of its molecules to each other
thermal stability
resistance to temperature change
chemical reactivity
ability to participate in chemical reactions
concentration
how much solute is present in a given volume of water
acid
A proton (H+) donor; a chemical that releases protons into solution
base
A chemical that binds protons from solution; a proton acceptor.
Acidity is expressed in terms of...
pH
Describe pH scale
0.0-14.0 pH 7.0- neutral pH below 7- acidic pH greater 7- basic (alkaline)
organic compound
any compound of carbon and another element or a radical
organic chemistry
the chemistry of compounds containing carbon
biochemistry
subdiscipline of organic chemistry that relates organic compounds to the processes of life
4 organic molecules of life
carbohydrates, lipids, proteins, and nucleic acids
macromolecule
any very large complex molecule; carbon forming chains
polymers
A molecule that consists of a long chain of identical or similar subunits, such as protein, DNA, or starch.
monomers
One of the identical or similar subunits of a larger molecule in the dimer to polymer range; for example, the glucose monomers of starch, the amino acids of a protein, or the nucleotides of DNA.
Living cells use a process called ____ ____ to join monomers together to form polymers
dehydration synthesis
Describe process of dehydration synthesis
remove hydrogen (-H) from one monomer and a hydroxyl group (-OH) from another, producing water as a by-product. Two monomers become joined by a covalent bond. This is repeated for each monomer added to the chain
hydrolysis
A chemical reaction that breaks a covalent bond in a molecule by adding an —OH group to one side of the bond and —H to the other side, thus consuming a water molecule.
Carbohydrates
A hydrophilic organic compound composed of carbon and a 2:1 ratio of hydrogen to oxygen; includes sugars, starch, glycogen, and cellulose.
what are the simplest carbohydrates
monosaccharides, simple sugars
examples of monosaccharides
glucose, fructose, and galactose
Disaccharides
A carbohydrate composed of two simple sugars (monosaccharides) covalently bonded together;
examples of disaccharides
lactose, sucrose, and maltose
Polysaccarides
A polymer of simple sugars
examples of polysaccharides
glycogen, starch, and cellulose
Glycogen
an energy-storage polysaccharide.
Glucose
blood sugar- energy source for most cells
Galactose
converted to glucose
Fructose
converted to glucose
Sucrose
Cane Sugar- digested to glucose and fructose
Lactose
Milk sugar- digested to glucose and galactose; important in infant nutrition
maltose
Malt sugar- product of starch digestion, further digested to glucose
cellulose
structural polysaccharide of plants; dietary fiber
Starch
Energy storage in plant cells; dietary source of energy for humans
Glycogen
energy storage in animal cells (liver, muscle, uterus)
Lipids
A hydrophobic organic compound composed mainly of carbon and a high ratio of hydrogen to oxygen
Triglycerides Functions
Energy storage; thermal insulation; filling space; binding organs together; cushioning organs
Fatty acid functions
precursor of triglycerides; source of energy
phospholipids function
major component of cell membranes
cholesterol function
component of cell membranes; precursor of other steroids
steroid hormones
chemical messengers between cells
bile acids
steroids that aid in fat digestion and nutrient absorption
Triglycerides are called ___ if solid and ___ if liquid
fats
oils
saturated fatty acid
a fatty acid whose carbon chain cannot absorb any more hydrogen atoms; found chiefly in animal fats
unsaturated fatty acid
a fatty acid whose carbon chain can absorb additional hydrogen atoms
polyunsaturated fatty acid
an unsaturated fatty acid whose carbon chain has more than one double or triple valence bond per molecule
difference between triglycerides and phospholipids
phospholipids have a phosphate group instead of one fatty acid
Note 
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