Biology 110 Exam 1 Comprehensive Notes - University of Louisiana at Lafayette

biology

study of life

atoms

smallest units of matter that form all chemical substances and all organisms; can be broken down into subatomic particles

molecules

2 or more atoms bonded together

cells

simplest unit of life; made of macro-molecules

tissues

cells of the same type associate with each other

organs

2 or more types of tissues

organism

all living things; species

population

organisms of same species in same environment

community

interacting population of different species

ecosystems

interactions of community of organisms with physical environment

biosphere

all places on Earth where living organisms exist

evolution

occurred 3.5-4 billion years ago

taxonomy

field of biology that groups and classifies species

bacteria, archaea, and eukarya

what are the 3 domains of life?

bacteria

unicellular prokaryote (no nucleus); found in diverse environments on Earth

archaea

unicellular prokaryote (no nucleus); found in extreme environments like hot springs

eukarya

unicellular and multicellular eukaryotes (complex cells with a nucleus)

binomial nomenclature

two part name used in the classification of living organisms; a unique scientific name; both names are italicized; has a genus and a species

genus

first part of a binomial nomenclature in which the first letter is capitalized; is italicized

species

second part of a binomial nomenclature that is NOT capitalized; also called the specific epithet; is italicized

genome

complete set of genetic material of an organism; carries information to make proteome; information is very stable

genomics

uses techniques to analyze DNA sequences

proteome

complete set of proteins of an organism

horizontal gene transfer

transfer of genetic material from one organism to another organism that is NOT its offspring

antibiotic resistance

conferred by genes that are sometimes transferred between bacteris species

vertical gene transfer

genetic material passed down from one organism to its offspring

peer-review process

process by which a scholarly article is reviewed by others in order to correct and/or verify the information in the article; reviewers are kept anonymous

matter

anything that has mass and occupies space; all life-forms are composed of it; exists in 3 states (liquid, solid, and gas)

element

pure substance made up of only one kind of atom (nitrogen, hydrogen, oxygen)

protons

subatomic particle found in an atom; has 1 unit of positive charge; in the nucleus

neutrons

subatomic particle found in atom; has a neutral charge; in the nucleus

electrons

subatomic particle found in an atom; has 1 unit of negative charge; outside of the nucleus

nucleus

has a net positive charge equal to the number of protons it contains

orbital

region around the nucleus of an atom where an electron is most likely to be found due to its unpredictable nature; can only have 2 electrons any more electrons means more than one orbital; can be spherical or dumbell shaped

electron shells

energy levels; place in which orbitals can be found

2 (in 1s orbital)

how many electrons can be in the first electron shells

8 max (2 in 2s orbital, 2 in each of the 3 p orbital)

how many electron can be in the 2nd electron shells

energy

capacity to do work or cause change

atomic number

amount of protons in an elements nucleus; also equal to the number of electrons

atomic mass

indicates an atom's mass relative to the masses of other atoms; measured in Daltons

kinetic energy

energy of moving matter

weight

gravitational pull on a given mass

6.022x10^23 (mol)

What is Avogadro's number?

isotopes

the multiple forms of elements that differ in the number of neutrons they contain; have similar chemical properties but different physical properties

radioisotopes

unstable isotopes; emit radiation as they decay, which converts them to a stable form

oxygen, carbo, hydrogen, and nitrogen

four major elements that account for 95% of atoms in living organisms

mineral elements

chemical elements that are required for life and present in significant amounts in living organisms; take up less than 1% of total mass in living organisms

trace elements

elements required in all living organisms that are present in extremely small quantities but are essential for normal growth and function

molecular formula (H2O, O2; the "2" is meant to be in the subscript for both)

consists of the chemical symbol and a subscript that tells how many atoms are present in the molecule

Give an example as well.

compound (H2O)

molecule composed of 2 or more different elements

covalent bonds

chemical bond in which 2 atoms share a pair of electrons; can occur between atoms whose outer shells are not full (making the bond strong)

single bond

bond between one pair of electrons

double bond

bond between two pairs of electrons

triple bond

bond between three pairs of electrons

octet rule

states that any atoms are most stable when they have 8 electrons in their outermost shell; does not apply to hydron and helium bc their one shell cannot hold 8

electronegativity

measure of an atoms ability to attract electrons in a bond with another atom; higher values attract electrons more strongly than lower electrons

oxygen and nitrogen

have a higher electronegativity due to having more protons

hydrogen and carbon

have a lower electronegativity due to having less protons

polarity

difference in electric charge across a molecule

nonpolar covalent bonds

bonds with similar electronegativities (means similar attraction to electrons); differ in electronegativities by less than 0.4

polar covalent bond

bonds between atoms with an electronegativity difference from 0.4-1.8; shared electrons are more likely to be closer to the nucleus of the atom with the higher electronegativity than to the nucleus of the atom of the lower electronegativity; distribution of the shared electrons around the nuclei creates a polarity across the molecule; is the unequal sharing of electrons

hydrogen bond

forms when a hydrogen atom in one polar molecule becomes electrically attracted to an electronegative atom in another polar molecule; represented by dotted-dashed lines; is a weak attraction bond between polar molecules that breaks easily

enzymes

molecules that catalyze many biologically important chemical reactions

ions

when an atom/molecule gains/loses one or more elctrons; net negative charge

ionic bond

occurs when a cation binds to an anion; may occur between atoms that differ greatly in the electronegativities; electrons are transferred, forming ions that are attracted to each other; forms electrostatic connection

chemical reactions

occurs when 1 or more substances are changed into other substances by the making or breaking of chemical bonds

cation

ions that have lost an electron, resulting in a net positive charge; example: Na^+

anion

ions that have gained an electron, resulting in a net negative charge; Example: Cl^-

free radical

a molecule containing an atom with a single, unpaired electron in its outer shell; can cause cell damage; can interact with other molecules to "steal" an electron from one of their atoms to fill the orbital; can be charged or neutral

nitric oxide (NO.) and superoxide (O2.-)

what are 2 examples of free radicals

chemical reaction

occurs when 1 or more substances are changed into other substances by the making or breaking of chemical bonds

1) need energy

2) need a catalyst

3) reach equilibrium eventually

what are the three properties shared by chemcal reactions

catalyst

agent that speeds up the rate of a chemical reaction

enzyme

example of a catalyst

solutes

substances dissolved in a liquid

solvent

liquid in which substances are dissolved

solution

formed when solutes dissolve in a solvent

aqueous solutions

solutions made with water

hydrophilic

"water-loving"; molecules that contain ionic and/or polar covalent bonds that dissolve in water

hydrophobic

"water-fearing"; molecules that have few or no partial positive and negative charges and are not attracted to water molecules

amphipathic

"both loves"; molecules that have both hydrophilic and hydrophobic regions at certain sites; may form micelles in water; have polar/ionized and nonpolar regions

detergent

what is an example of an amphipathic molecule

micelles

spheres of long amphipathic molecules; polar (hydrophilic)regions are at the surface of each and the nonpolar (hydrophobic) regions oriented toward the interior

concentration

amount of a solute dissolved in a unit volume of a solution

antifreeze molecules

produced by some animals; lowers the freezing point of body fluids to prevent blood and cells from freezing

molecular mass

the sum of the atomic masses of all the atoms in a molecule

1 mol

amount of substance in grams equal to its molecular mass or atomic mass

solid (ice), liquid (water), gas (vapor)

three states of H2O

liquid form of water

extremely stable due to high vaporization and fusion temperatures and high specific temperature

molarity

number of moles of a solution dissolved in 1 L of a solution

heat of vaporization

heat/energy input required to vaporize 1 mol of any substance

heat of fusion

amount of heat that must be withdrawn/released for a liquid to change to a solid state

specific heat

amount of heat required to raise/lower the temperature of 1 gram of a substance by 1 degree Celsius

dense

ice is less ______ than liquid water and floats because hydrogen bonds are stable and very far apart in ice

continually break and reform

in liquid water, hydrogen bonds...

0 C

freezing point of water

100 C

boiling point of water

colligative properties

temperatures a solution freezes/vaporizes at is influenced by the amounts of dissolved solutes; properties that depend strictly on the total number of dissolved solute particles

evaporative cooling

energy in the form of heat dissipates from an organism when sweat evaporates; occurs as hydrogen bonds break and the liquid converts to gas

cohesion

molecules of the same type attract each other