Anatomy Chapter 2.1, 2.2, 2.3 (Atoms, Ions, Molecules)
classes of chemical reactions
- processes where atoms, ions, molecules, or compounds interact to form new bonds or to break existing chemical bonds -how we define different types of reactions
Elements in Humans
-26 different ones but 4 major ones (C, O, H, N) -make up 96% of the bodies mass.
mixture
-A combination of two or more substances that are combined physically but not chemically -each substance retains its own chemical property Ex) dry salt and sugar
surface tension
-A measure of how difficult it is to break the surface of a liquid, this is why heavy objects will float -if it is put in below surface, it will sink
electron clouds/electron shells
-Actually electrons form a negatively charged cloud (around nucleus) -electron shells predict the regions where certain numbers of electrons will spend most of their time.
Ionic Bonding
-Attraction of opposite forces (cations and anions are attracted to each other) -one atom loses while the other gains one or more electrons
reaction rates
-Basis for chemical reactions is molecular motion. -reactions-> products -how energetically they are going to come together for reactants to be products
Mass number
-Numbers of protons plus the number of neutrons -Protons and neutrons are about equal in mass Ex) Carbon 6p and 6n, it would be 12
examples of ionizing radiation
-UV Rays -X rays •Alpha Particles •Beta particles •Gamma Rays • = all three come from nuclear decay
Hydrophobic
-Water fearing -contain mainly non polar covalent bonds -do not easily dissolve in water Ex) fats and oils
Antioxidant
-a chemical that neutralizes free radicals -food has some, there is drugs for it
reduction
-a reaction where a molecule gains electrons and gains energy -follow the electron
pH scale
-a scale from 0 (acidic) to 14 (alkaline) which expresses how acidic or basic a solution is -based on the concentration of (H+) in moles per liter
emulsion
-a suspension of one liquid in another (special case) -looks mixed for a little time, then have to shake Ex)oil and vinegar salad dressing
Metabolism
-all chemical reactions in the body -catabolic and anabolic
anabolism
-all of the synthesis reactions that occur in the body -usually endergonic (need input of energy)
Number
-always equals the number of protons
mole
-amount of substance that has a mass in grams that equals the sum of the atomic masses of all the atoms present in the sample (molecular weight) Ex) 1 Mole NaCl = 58.44g (Na= 22.99 and Cl=35.45). ->molecular weight
concentration
-at pH 7, there is one ten millionth (0.0000001) of a mole of (H+) per liter -whole number change along the scale represents a 10 fold change in the number of (H+) present
Calorie
-base unit of heat measurement (cal) - 1 is the amount of heat needed to raise the temperature of one gram of water 1*C Ex) 1 gram of water 40* to 41* needs one calorie
reversible reactions
-can proceed in either forward or reverse directions -Forward: toward the products or to the right -Reverse: toward the reactants or to the left -don't proceed to completion b/c products can react together to reform reactants
buffer
-chemical compounds that convert strong acids and bases into weaker acids and bases by removing or adding (H+) -work to resist rapid and big changes in the pH of a solution
Molecules
-chemical particles composed of two or more atoms (could be same or different) united by a chemical bond -atoms may be the same (N2) or different (C6H12O6)
Isotopes
-different atomic forms of the same element -same numbers of protons and electrons, but different numbers of neutrons -most are stable
free radical
-electrically charged atom or group of atoms with an unpaired electron in its outermost shell (odd number) -produced by some normal metabolic process, radiation, some chemicals -unstable, very reactive, damaging
Non polar covalent bond
-electrons are shared equally -strongest of all bonds
Valence Electrons
-electrons in outermost shell -most energetic, most interactive -atoms tend to bond, so to fill outer shells, we use octet rule (most stable 8, then 6, because 7 would have extra)
free energy
-energy that is available to do work -what we can use to get work done
Atomic number
-equal to the numbers of protons in each atom -also equal to the number of electrons Ex) Carbon has 6 protons, so _____ is 6
Chemical bonds
-forces that hold molecules or compounds together -Depending on the number of electrons in its outer (valence) shell, the atom may or may not interact with another atoms
Nucleus
-formed by protons and neutrons -have about the same mass= 1amu
Ionizing Radiation
-high energy radiation -ejects electrons from atoms (unbalanced) , converting them to ions -destroys molecules and creates free radicals (damaging, need document for metal detectors)
electrolyte concentration
-important due to their electrical and osmotic properties -amount of charge is important (affects osmotic properties)
Shells/levels
-innermost hold 2 electrons, next holds 8, then 18 in remaining -a way to predict how many electrons and where they'll be
Minerals
-inorganic elements extracted from soil by plants -in body from consuming plants/animals
electrolyte
-ionic compound that breaks apart into positive and negative ions in solutions -good conductors of electricity
suspension
-large particles, cloudy or opaque -too large for selectively permeable membranes -solutes will eventually settle out (fall to bottom) Ex) blood
colloid
-larger particles, scatter light so they can look translucent opaque -solutes do not settle out, they are usually too large to pass through semipermeable membranes Ex) milk
percentage
-mass per volume % -relative mass of a solute in a given volume of solvent, or if solute is a liquid (70% ethanol v/v, 30% water) Ex) IV dextrose D%W is 5% dextrose w/v (5% dextrose 95% water)
neutral
-mid point of the scale a 7 -here the concentration of (H+) and (OH-) are equal Ex) double distilled pure water
heat
-molecules are always moving, byproduct of kinetic -kinetic energy of molecular motion
molarity
-moles per liter (mol/L) -number of moles of solute per liter of solution
water
-most important inorganic compound in living systems -held together by polar covalent bonds -V shaped, as a whole polar molecule -most important properties (partial charge and shape)
PH
-no rapid changes -right more hydroxide, left more hydrogen -Add hydrogen to make more acidic, or subtract hydroxide ions to make basic
Chemical Symbol
-one or two letters that represent an element -some make sense, some dont
exchange reactions
-part synthesis and part decomposition -switch partners Ex) AB+ CD = AD
importance
-plays role in determining the 3d shape of complex molecules or the interactions between molecules, like in water -while individually weak the additive forces can be substantial
Temperature
-reaction rates increase when ____ increases -heat makes them move quicker
base
-referred to as a proton donor -often dissociate in water, they separate into one or more hydroxide (not always) ions (OH-), and one or more cations -In solution, base does not always have to release hydrogen ion (part it releases has a negative charge) Ex) NaOH Na+ + OH-
Atoms
-smallest particle of an element that has chemical characteristics -composed of subatomic particles -electrically neutral
solution
-solutes remain evenly dispersed, particles are small, up to 1 nanometer, they do not settle out -solutions look clear or transparent (do n to scatter light) -solutes will pass through most selectively permeable membranes (dialysis tubing or cell membranes)
dalton
-standard unit of measurement for measuring the mass of atoms -also known as AMU
potential energy
-stored energy that results from the position or shape of an object -chemical bond energy
Chemical Elements
-substances that cannot be split into simpler substances by ordinary chemical means -118 (always changing), 91 naturally occurring -24 in human physiology, small amounts, if they grow can be a problem
Water in chemical reactions
-the ideal medium for most metabolic reactions -water ionizes other things and also can be ionized (able to pass electric current)
Equilibrium
-the point where reactants= product formation **does not mean reaction stops -net effect= 0
Element
-the simplest form of matter that has a unique set of properties Ex) Atom of Carbon=smallest form of matter to act like carbon
cohesion
-the tendency of molecules of the same kind to stick together -when putting water molecules together, they want to stay -Water droplets going together
Half Life
-the time it takes for half of the atoms of a radioactive element to decay into a more stable form (physical) -time required for half a radio isotope to leave the body (biological)
Radioisotopes
-unstable isotopes whose nuclei decay (decay) -move towards a more stable configuration -emit radiation as they decay (can be problematic)
Thermal properties of water
-water can be absorb or release considerable amounts of heat with only moderate changes in its own temperature -has a high heat capacity as well as high heat of vaporization (add heat to water until boiled)
dehydration
-water is removed as two molecules combine -one main molecule plus water
hydrophilic
-water loving -charged solute or solutes that contain polar covalent bonds -dissolve in water easily Ex) salt or sugar
van der Waals forces
-weak, brief attractions between atoms (or molecules) that are neutral -about 1% as strong as covalent bond, but when surfaces meet or molecules are large, these forces can be significant
weight per volume
-weight of solute in given volume of solution -IV saline: 8.5 grams NaCl/liter of solution -solute in solvent
van der Waals forces
-why plastic wrap works, and why spiders can walk upside down -significantly affect the boiling points of liquids -are important in humans for protein folding and binding (to take shape) -association of lipids to each other (occur where surfaces meet)
chemical energy
A form of potential energy that is stored in chemical bonds between atoms.
Solution
A mixture that forms when one substance dissolves another. -liquid, solid, gas uniformly distributed
Anion
A negatively charged ion (gained 1 or more electrons)
Hydrogen bond
A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule. -nothing would exist without them -only in hydrogen, oxygen, nitrogen, or fluorine
Valence shells
Atoms with unfilled valence (outermost) shells containing unpaired electrons are the most likely to interact and form bonds.
inorganic compounds
Compounds that do not contain carbon
Water as a solvent
Most versatile solvent known but not considered a universal solvent (not everything)
States of Matter
Solid- Definite shape and volume Liquid- Definite volume (takes shape of container) Gas- Doesn't have definite shape or volume
Acids, Bases, and pH
These substances dissociate in water, they separate into ions and become surrounded by water molecules
intracellular and extracellular
What fluid must contain the proper quantities of acids and bases ? (this contributes to the correct chemical environment for physiological processes to occur)
Ions
When an atom gains or looses electrons and becomes charged
double covalent
a bond in which two atoms share 4 (two pairs) of electrons
oxidation
a reaction where a molecule gives up electrons and releases energy
Catabolism
all the body's composition reactions, mainly exergonic (give off energy, builds bonds of heat)
covalent bonding
atoms share one or more pairs of electrons *don't totally give up electron
atomic mass
average mass of all the naturally occurring isotopes
Polar covalent
electrons are not shared equally
kinetic energy
energy of motion
catabolism
energy releasing decomposition reactions
anabolism
energy storing synthesis reactions
decomposition reaction
larger molecules are broken into smaller ones Ex). NaCl Na+ Cl
Compounds
molecules made of two or more different elements Ex) H2O
Isomers
molecules with identical formulas but different arrangements
Cation
positively charged ion (atom has lost 1 or more electrons)
law of mass action
proceed from the reactants in greater quantity to the substances with the lesser quantity
Subatomic particles
protons-positive neutrons-neutral, no electric charge electron- negative charge
concentrated
reaction rates are increased when reactants are more ____?
Acid
referred to as a proton donor dissociates into one or more hydrogen ions (H+) and an anion (negative ion) Ex). HCL-> H+ + Cl- (gives up electron)
catalyst
speeds up reaction, makes them more likely to interact
one equivalent (Eq)
the amount of an electrolyte that would neutralize 1 mole of hydrogen (H+) or hydroxide (OH-) ions
energy
the capacity to do work
Hydrolysis
the chemical breakdown of a compound due to reaction with water. (decomposition reaction)
electromagnetic energy
the kinetic energy of moving "packets" of radiation called photons
Acidity
the more free hydrogen (H+) in a solution, the more acidic it is
Alkalinity
the more free hydroxide (OH-) in a solution, the more basic/alkaline it is
Solvent
the substance in which the solute dissolves Ex) when mixing warm water and sugar, it would be warm water
Solute
the substance that is dissolved Ex) when mixing warm water and sugar, it would be sugar
Molecular Weight
the sum of the atomic weights of all the atoms in a molecule
adhesion
the tendency of water to stick to other substances Ex) why you have to dry off, water on skin
work
to move something
Triple covalent bond
two atoms share 6 (3 pairs) electrons
single covalent
two atoms share two electrons (one pair)
Octet Rule
two or more atoms interact in ways that produce a chemically stable arrangement of 8 valence electrons for each atom
synthesis reaction
two or more reactants chemically combine to form a larger product do not lose or gain Ex) N2+ 3H2= 2NH3
strength
weak bond compared to ionic or covalent bond shows example of ____ ?