Chapter 2 chemical level of organization Flashcards
Principle elements of human body
O2-oxygen, C-carbon, H-hydrogen, N-nitrogen. Secondary: Ca2+-calcium, Ch-chlorine, K-potassium, S-sulfur, P-phosphorus, Na+ sodium, Mg-magnesium, Fe-iron.
atom
the smallest units of matter that retain the properties and characteristics of the element.
nucleus, proton, neutron, electron
. The dense central core of an atom is its nucleus. Within the nucleus are positively charged protons (p+) and uncharged (neutral) neutrons (n). The tiny, negatively charged electrons (e-) move about in a large space surrounding the nucleus.
electron shell (valence shell)
simple circles around the nu- cleus. Because each electron shell can hold a specific number of electrons, the electron shell model best conveys this aspect of atomic structure
atomic number
number of protons
atomic mass
number of protons +neutrons
isotopes
are atoms of an element that have different numbers of neutrons and therefore different mass numbers.
atomic mass
Dalton/atomic mass unit- average mass of its common occurring isotope
Ion
is an atom that has a positive or negative charge because it has unequal numbers of protons and electrons
Ionization
is the process of giving up or gaining electrons.
molecule
2 atoms of same kind
compound
2 or more atoms of different elements
free radical
atom or group of atoms with unpaired electron in outermost shell- unstable, reactive and desctructive
Octet rule
valence shell can only hold 8, stable, barely binds
ionic bond
cation +, anion- bind by neg and pos charge, cation donates electron to anion.
electrolyte
ionic compound that breaks apart into + & - ions in solution
covalent
share electron
single covalent bond, double covalent bond, triple covalent bond
2 atoms share one electron pair, share 2 pairs, share 3 pairs
non-polar covalent bond
two atoms share the electrons equally—one atom does not attract the shared electrons more strongly than the other atom.
electronegativity
power to attract electrons to itself. (greater pull=greater electronegativity)
hydrogen bond
(weakest bonds), hydrogen bond forms when a hydrogen atom with a partial positive charge attracts the partial negative charge of neighboring electronegative atoms, most often larger oxygen or nitrogen atoms. hydrogen bonds result from attraction of oppositely charged parts of molecules
surface tension
measure of difficulty of stretching or breaking the surface of liquid
chemical reaction
occurs when new bonds form or old bonds break between atoms.
products/reactants of chemical reaction
end substance=product, starting substance=reactant
catalyst
enables a chemical reaction to produce faster, ex.enzyme
synthesis reaction
anabolism- react for form a single product
decomposition reaction
catabolism- break down molecules into two or more substances
exchange reaction
weak electrolytes/ions, exchange products for one another HCL+ KOH = KCL + H2O
reversible reaction
A reversible reaction is a chemical reaction where the reactants form products that, in turn, react together to give the reactants back
oxidation/reduction reaction
Oxidation is loss of electron, reduction is gain of an electron
inorganic/organic compound
usually lack carbon and are structurally simple/ always contain carbon, usually contain hydrogen, and always have covalent bonds
water, water as a solution/solvent/solute
water an excellent solvent for other ionic or polar substances, gives water molecules cohe- sion (the tendency to stick together), and allows water to resist temperature changes.
/ In a solution, a substance called the sol- vent dissolves another substance called the solute
hydrophilic/hydrophobic
water loving/water hating substances
hydrolysis
decomposition reactions break down large nutrient molecules into smaller molecules by the ad- dition of water molecules
dehydration synthesis reaction
when two smaller molecules join to form a larger mole- cule in a dehydration synthesis reaction (de- from, down, or out; hydra- water), a water molecule is one of the products formed
heat capacity
water can absorb or release a relatively large amount of heat with only a modest change in its own temperature
mixture, colloid, solution, suspension
mixture: blend together but not bonded by chemical bonds,
colloid: large particles (appear translucent or opaque)
solution: remain evenly dispersed among solvent
suspension: may mix for a bit but will settle out (blood)
concentration (and moles)
mol/L, solute/solution
1 mol=atomic mass of molecule
1 mol of NACL=58.44 grams as atomic mass is 58.44
Acid (hydrogen ion)
disassociate into one or more hydrogen ions (proton donor)
H+
base
remove H+ from solutions (proton accept)
hydroxide ion OH-
salt
NACL,
Define the term pH, and explain the role of buffer systems in homeostasis
This scale is based on the concentration of H in moles per liter. A pH of 7 means that a solution contains one ten-millionth (0.0000001) of a mole of hydrogen ions per liter.
which function to convert strong acids or bases into weak acids or bases. Strong acids (or bases) ionize easily and contribute many H (or OH) to a solution. Therefore, they can change pH drastically, which can disrupt the body’s metabolism. Weak acids (or bases) do not ionize as much and contribute fewer H (or OH). Hence, they have less effect on the pH. The chemical compounds that can convert strong acids or bases into weak ones are called buffers
carbonic acid bicarbonate buffer system
Carbonic acid (H2CO3) can act as a weak acid, and the bicarbonate ion (HCO3-) can act as a weak base. buffer system can compensate for either an excess or a shortage of H+.
macromolecules
polymers
monomers
isomers
Small organic molecules can combine into very large mole- cules that are called macromolecules.
A polymer is a large molecule formed by the covalent bonding of many identical or similar small building-block molecules called monomers.
Molecules that have the same molecular formula but different structures are called isomers.
carbohydrate- monosaccharide disaccharide polysaccharide; starches; cellulose glycogen
monosaccharide/disaccharide (2 monosaccharides)-simple sugars.
Cells throughout the body break down the hexose (6 carbon) glucose to produce ATP.
polysaccharide- ten to millions of monosaccharides joined by dehydrated synthesis
lipid
insoluble in h2o and hydrophobic.
lipoprotien
lipid molecules join with hydrophilic protein
fatty acid; saturated and unsaturated
fatty acid-simplest lipid, building blocks of triglycerides
A saturated fatty acid contains only single cova- lent bonds between the carbon atoms of the hydrocarbon chain. Because they lack double bonds, each carbon atom of the hy- drocarbon chain is saturated with hydrogen atoms.
An unsaturated fatty acid contains one or more double covalent bonds between the carbon atoms of the hydrocarbon chain. Thus, the fatty acid is not completely saturated with hydrogen atoms (kink or bend in chain)
triglyceride =triacylglycerol
glycerol
most plentiful lipids in your body and in your diet
A triglyceride consists of two types of building blocks: a single glycerol molecule and three fatty acid mole- cules. A three-carbon glycerol molecule forms the backbone of a triglyceride
Phospholipid
amphipathic
Phospholipid- have a glyc- erol backbone and two fatty acid chains attached to the first two carbons,
amphipathic-Molecules that have both polar and nonpolar parts are said to be amphipathic
steroid
cholesterol
steroid-four ring carbon atom- slightly ampipathic
cholesterol-Body cells synthesize other steroids from cholesterol, needed for cell membrane structure
eicasanoids:
prostaglandins
leukotrienes
eicasanoids: lipids derived from a 20-carbon fatty acid called arachidonic acid.
eicasanoids subclasses:
They modify responses to hormones, contribute to the inflammatory response (Chapter 22), prevent stomach ulcers, dilate (enlarge) airways to the lungs, regulate body temperature, and influence formation of blood clots, to name just a few. Leukotrienes participate in allergic and inflammatory responses.
function of protien
1) (structural) Form structural framework of various parts of body
2) (regulatory)Function as hormones that regulate various physiological processes; control growth and development; as neurotransmitters, mediate responses of nervous system.
3) (contractile) Allow shortening of muscle cells, which produces movement.
4) (immunologic)- Aid responses that protect body against foreign substances and invading pathogens.
5) (transport)-carry vital substances around the body
6) (catalytic)-Act as enzymes that regulate biochemical reactions.
