Bio Terms

• substance that cannot be broken down chemically into any other
• substances. Gold, carbon, and copper are elements you might be
• familiar with.
• - each element has an atomic number –
• corresponds with the number of protons

• a
• bit of matter that cannot be subdivided any further without losing
• its essential properties. The word “atom” is from the Greek for
• “indivisible.”

• center of an atom, made of 2 types of particles called protons and neutrons
• small and compact - leaves a lot of space for neutrons to zip around

particles with positive electrical charge

• particles with no electrical charge
• usually about same of each in an atom

• amount of matter in a particle
• protons and neutrons together
• number of protons determines the element

• whirling in a cloud around nucleus - negatively charged
• weighs almost nothing - less than 1/20th of protons

made of combined mass of all protons and neutrons

• atom with less or more neutrons than protons (rare)
• carbon -13 and carbon -14 "heavy carbon"
• same atomic number, diff mass

• in the process of decomposition they realease
• tiny high speed particles carrying a lot of energy
• useful for determining age of fossils, cancer treatment, vast amount of energy

elements arranged according to their atomic number

• element that make our body
• oxygen, hydrogen, nitrogen and carbon
• 96% of body mass

• Electrons stay within prescribed area in an atom - the shell
• each electron has its own shell
• electrons stay far apart because their negative charge repels them

• First shell of the atom has most of the time has 2 netrons, every other shell 8
• can have up to 7 shells

• number of electrons in most outer shell
• most stable when all electrons are filled

hold atoms together by bonds

the energy with which atoms are held together

• a strong bond formed when atoms share electrons to become more stable - form a molecule (attach)
• ex. H2

• an attraction btw 2 oppositely charged ions - forming a compound
• - atom gaining an atom will be - negatively charged
• losing - positively

a molecule made of 2 or more parts

• weak bond
• between slightly positively charged hydrogen atom of one molecule and slightly negatively charged atom of another

• attracted to other polar molecules
• line up in particular orientation such that the positive regions of molecule are near negative of another

because of their unequally shared electrons

• cohesiveness
• reduced density
• ability to resist temperature changes
• effectiveness as a solvent for ionic and polar substances

the amount of H+ in a solution is a measure of acidity

• Any fluid with a pH
• below 7.0 has more H+ ions (and fewer OH−
• ions)

• Any fluid with a pH
• above 7.0 has fewer H+ ions (and more OH−
• ions)

• the lower the number the greater the acidity
• a decrease of 1 on the pH scale represents 10-fold increase in the hydrogen ion concentration

• chemicals that absorb excess H+ ions to keep a solution from becoming too acidic
• chemicals that act to resist changes in pH

measure how acidic or basic the solution is

• large molecules made up from smaller building blocks or subunits—are
• essential to the building and functioning of living organisms:
• carbohydrates, lipids, proteins, and nucleic acids.

• molecules that contain mostly carbon, hydrogen, and oxygen: they are
• the primary fuel for running all of the cellular machinery and also
• form much of the structure of cells in all life forms
• not all are digestable by humans

• cannot be broken
• down into other simple sugars; examples are glucose, fructose, and
• galactose.

• a web of molecules form together by stored glucose molecules
• - prime form of short term energy storage in animals

• Carbohydrates formed by the union of
• two simple sugars, such as sucrose (table sugar) and lactose (the
• sugar found in milk).

• Complex carbohydrates formed by the
• union of many simple sugars.

• multiple amount of simple sugars
• primary form of energy storage in animals

• A complex carbohydrate, indigestible by
• humans, that forms the rigid outer skeleton of most insects and
• crustaceans.

• One of four types of macromolecules,
• lipids are insoluble in water and greasy to the touch; they are
• important in energy storage and insulation (fats), membrane formation
• (phospholipids), and regulating growth and developmen

• Repelled by water, as, for example,
• nonpolar molecules that tend to minimize contact with water

• Attracted to water, as, for example,
• polar molecules that readily form hydrogen bonds with water.

• A small molecule that forms the head
• region of a triglyceride fat molecule

• A long hydrocarbon (a chain of
• carbon-hydrogen molecules); fatty acids form the tail region of
• triglyceride fat molecules.

proteins that help initiate and speed up chemical reaction

store info on how to run the body

• universal translator of genetic code into proteins
• reads DNA - produces AMINO acids

lipid important in growth in development

molecule on which the enzyme acts

• The unique and complex three-dimensional shape formed by multiple twists
• of the secondary structure of a protein as amino acids come together
• and form hydrogen bonds or covalent sulfur-sulfur bonds

An unsaturated fat that has been partially hydrogenated

A fat having three fatty acids linked to the glycerol molecule

A lipid similar in structure to fats but with only one long-chain fatty acid linked to the glycerol head of the molecule