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Bio Test 1
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Biology
Undergraduate 1
09/06/2015

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Term
Theory
Definition
a general set of principles, supported by evidence, that explains some aspect of nature. Has explanatory power.
Term
Variable
Definition
an adjustable condition in an experiment
Term
Proven Theories
Definition
nothing is ever finally proves; science is always subject to change
Term

ScientifiC Process

 

 

 

 

 

Definition

1) every assertation regarding the natural world is subject to change

2)any scientific hypothesis must be falsifiable (open to negation through scientific inquiry)

3) scientific inquiry is only concerned with natural explanations for natural phenonama. not god or fairies

Term
Biology
Definition
study of life
Term
Life
Definition

1) can assimilate (take in) energy

2) respond to environment

3) mantain a relatively constant internal environment

4) posses DNA 

5) can reproduce thru info in DNA

6) composed of one or more cells

7) evolved from other living things

8) highly organized compared to inanimate objects

Term
Hierarchy
Definition

living things are organized in a hierarchical manner (lower levels make up higher levels)

atom-molecule-organelle-cell-tissue-organ system-organism-population-community-ecosystem-biosphere

Term
Evolution
Definition

biologies chief unifying principle

the gradual modification of populations of living things over time

Term
The Atom
Definition

chemistries building block

composed of nuetrons, protons, electrons

make up molecules

 

Term
Element
Definition

"pure" cannot be reduced to any simpler set of component substances through chemical processes

defined by # of protons (atomic number)

 

 

Term
isotopes
Definition

various forms of elements due to variation of the number of nuetrons in an elements nucleus

carbon (normally has 6 p, 6 n. carbon 14, 8 n, 6 p)

Term
Energy always
Definition
seeks its lowest state. chemical bonds occur because atoms want to be more stable, by filling their outer shells.
Term
Energy Levels of an Atom
Definition

Electrons reside in outer energy levels. 

2 electrons required to fill first energy level (shell)

8 required to fill every other energy shell. 

Term
Covalent Bond
Definition

a chemical bond in which atoms share pairs of electrons

ex) H2O; hydrogen shares its electrons w oxygens outer shell

no matter is gained or lost

Term
law of conservation of mass
Definition
matter is neither created or destroyed in a chemical reaction
Term
molecule
Definition
atoms covalently bonded together
Term
Reactive v unreactive
Definition

atoms with filled outer shells are stable, do not want to bond

1- most reactive

8- least reactive

Term
Electronegativity
Definition
the power of an atom to attract electrons to itself
Term
Polarity
Definition

difference in electrical charge at one end of a molecule from another

more electrons on one end; more negatively charged

polar covalent bond

Term
non polar covalent bond
Definition

electrons are shared equally; methane, hydrogen bonds 

symmetric

Term
ion
Definition

a charged atom (has lost or gained an electron(s), therefore the number of electrons differs from the number of protons) 

ex) Na+if Sodium lost 1 electron, or if magnesium lost two electrons Mg2+

Term
Electrostatic Attraction
Definition
positive charged attracted to a negative charge
Term
Ionic Bonding
Definition
when atoms (ion) bond due to their electrostatic attraction.
Term
molecular formula
Definition

# of atoms of oxygen (O2)

# of molecules of atoms of Oxygen (3O2)

 

Term
Structural Formula
Definition

two dimensional representations of a given molecule.

single line = bond, represents one pair of electrons being shared

can explain ordering of atoms in a molecule, tell little about the 3 dimensional arrangements of atoms

Term
ball and stick model
Definition

better idea of molecular angles

spacefilling model; relative size, how they mold together

Term
reactant---> product
Definition
Term
ionic compound
Definition

a collection of the atoms of two or more elements that have become linked through ionic bonding

NOT a molecule.

linked through ionic bonds NOT covalent

combine via electric attraction, do not physically share electrons 

Term
Hydrogen Bonds
Definition

covalently bonded hydrogen atom with an electronegative atom.

H almost always bonded w oxygen or nitrogen 

indicated by a dotted line

relatively weak compare to ionic/covalent

 constantly breaking and reforming (h bonds close together in liquid water), (in ice they sit far apart because maximum # of bonds reached, therefore less dense)

heat=motion of molecules...

to move molecules bonds most be broken...

water has a lot of H bonds, requires lots of energy to break those bonds

Term
molecular shape
Definition
determines the capacity of a molecule to bind with another
Term
WATTTAA
Definition

humans are 66% water by weight 

living things are not functional without water

 great solvent because polar and therefore keep ions evenly dispersed, and ability to form hydrogen bonds

 

Term
solution
Definition

a mixture of two or more molecules, atoms, ions that is homegeneous throughout

 

Term
solute
Definition
what is being dissolved
Term
solvent
Definition
what is doing the dissolving
Term
specific heat
Definition
amount of energy required to raise the temperature of a substance by 1d C. Waters high specific heat allows it to release heat when its environment is colder than the water. aka water is a great buffer for the earth (absorbs energy from sun, releases energy when air gets colder).
Term
cohesion
Definition
tendency of water molecules to stay together
Term
nonpolar covalent molecules
Definition

cannot be dissolved aka methane

no electrical charge, water doesnt want to bond

Term
Hydrocrabons
Definition
made solely of hydrogen and carbon
Term
hydrophillic
Definition
water loving (form hydrogen bonds)
Term
hydrophobic
Definition
water fearing (do not form hydrogen bonds)
Term
Ph Scale
Definition

power of Hydrogen

measures the relative acidity of a substance

based off of concentration of Hions in solution

0- most acidic, 14- most basic, 7- nuetral

logarithmic; pH of 9 is 10 times as basic as 8, 100 times more basic as 7

Term
acid
Definition

YEILDS h atoms when put in an aqueous solution.

acidic solution has a higher concentration of H+ ions 

Term
bases
Definition

accepts hydrogen atoms in an aqueous solution

basic solution also reffered to as a alkaline solution

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