Ch 2 Chemistry
anything that occupies space and has mass
states of matter
solid, liquid, gas
has definite shape and volume
has no definite shape and definite volume
has no definite shape and no definite volume
the capacity to do work or put matter into motion
stored energy; has the capability to do work but is not now doing so
energy in action
forms of energy
chemical, electrical, mechanical, radiant
stored in the bonds of chemical substances (food molecules, ATP)
movement of charged particles
energy directly involved in moving matter
energy that travels in waves (electromagnetic spectrum)
What is an element
unique substances that cannot be broken down by ordinary chemical methods
What are Physical properties
things that can be detected with our senses or measured (color, texture, boiling point)
describe how atoms react with other atoms
An atom has three subatomic particles
protons, neutrons, and electrons
The central nucleus of an atom is composed of?
protons and neutrons.
How are the subatomic particles charged?
Protons are positively charged
neutrons are neutral (no charge)
Electrons Negatively charged
Where are electrons located
orbiting the nucleus in an electron cloud
Why does an atom have an overall neutral charge?
there are equal numbers of protons and electron
What is an atomic nunber
number of protons in an element
List the four major elements of the body
carbon, oxygen, hydrogen, and nitrogen (96% of body weight)
What are the most important minerals for the body? (9)
calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium, iodine, and iron.
What are the trace minerals needed? (11)
chromium, cobalt, copper, fluorine, manganese, molybdenum, selenium, silicon, tin, vanadium, and zinc
combination of two or more atoms held together by chemical bonds When the two atoms are identical the resulting substance is called a molecule of that element (H2 is a molecule of hydrogen gas).
when two or more different kinds of atoms bind they form molecules of a compound; chemically pure; all molecules identical (H2O is a compound – it is a molecule of water).
substances composed of two or more substances physically intermixed.
homogeneous mixtures of components that may be gases, liquids, or solids. [air, seawater]
substance in a solution present in the greatest amount (dissolving medium) [water]
substance in a solution present in smaller amounts (thing that is dissolved) [salt]
The outermost energy level is called
Atoms are most stable when the outermost shell has
(The exception to this is hydrogen and helium, which only have one energy level that is filled to capacity and is stable with only 2 electrons.)
Atoms are neutral, but they can gain or lose electrons. When this happens an atom becomes an?
An ionic bond is a
chemical bond between atoms formed by the transfer of one or more electrons from one atom to another. An example is sodium chloride (NaCl), table salt.
A covalent bond is a
chemical bond formed between two atoms that are sharing a pair of electrons, each atom contributing one electron to the shared pair.
If the atoms are shared equally then the resulting molecule is
nonpolar (hydrogen gas).
a polar molecule
If one atom has a greater attraction for electrons (a property known as electronegativitiy), the electrons may be shared unequally (water)
Hydrogen bonds form when
a hydrogen atom, already covalently linked with one electronegative atom (like oxygen or nitrogen), is attracted by another electronegative atom and forms a bridge between them.
synthesis reactions are
constructive (anabolic) and absorb/use energy (endergonic)
break things down (catabolic) and release energy (exergonic)
break bonds and then re-form other bonds to make new compounds.
speed up the reaction A catalyst is not chemically changed by the process and can be re-used
Water has several important properties:
- high heat capacity – absorbs and releases large amounts of heat before changing appreciably in temperature itself.
- high heat of vaporization – large amounts of heat are needed to break water’s hydrogen bonds and allow it to change from a liquid to a gas (evaporation).
- polar solvent properties – the universal solvent. The chemical reactions of the body depend on the reactants being dissolved in water.
- reactivity – decomposition reactions by hydrolysis; large molecule assembly by dehydration synthesis
substances that release hydrogen ions (H+) in detectable amounts. (1-6.9)
take up hydrogen ions in detectable amounts and are characterized by the presence of hydroxyl ions (OH-) (7.1-14)
Blood must maintain a pH in the range of
sugars and starches they are composed of carbon, hydrogen, and oxygen
simple sugars, example glucose (the major fuel source for the body).
composed of two sugar units, for example table sugar or sucrose (glucose + fructose).
composed of many sugar units, for example starch (the storage carbohydrate of plant tissues) and glycogen (the storage carbohydrate of animal tissues).
The primary function of carbohydrates in the body is
to serve as a source of cellular fuel
insoluble in water, but dissolve readily in other lipids and organic solvents like alcohol. Lipids include neutral fats, phospholipids, and steroids.
neutral fats, composed of a backbone of glycerol with three attached fatty acid chains. Neutral fats provide the body’s most efficient and compact form for storing usable energy fuel
similar to triglycerides except one fatty acid chain is replaced by a phosphate group.
Proteins are composed of building blocks called
amino acids joined by peptide bonds.
Small chains of less than 50 amino acids
Proteins are chains of
more than 50 amino acids and often will have 100-10,000 amino acids
Fibrous proteins such as collagen make up a large part of
Globular proteins include
hormones and enzymes
DNA and RNA
provides the instructions for how to make a single protein chain
DNA (deoxyribonucleic acid)
is the genetic material
RNA (ribonucleic acid)
assists in gene expression by carrying the code for a protein to the place in the cell that proteins are manufactured
ATP (adenosine triphosphate) is
a nucleotide which serves as the energy carrier molecule in the cell