bsc2010 exam 1

ion

charged atom/moleclue

anion

negatively charged ion

cation

positively charged ion

non-polar covalent bond

atoms share electron equally

Polar covalent bond

one atom is more electronegative. atoms do not share the electron equally

unequal sharing of an atom

partial positive or negative charge for each atom\

electronegatively

atoms attraction for the electrons in a covalent bond

the more electronegative an atom..

the more strongly it pulls the shared electrons toward itself

bonding capacity

an atoms valence

chemically inert

element with a full valence shell

valence electrons

electrons in the outermost shell

chemical behavior of an atom

is determined by the distribution of elections in the electron shell. mostly, valence electrons

isotopes

2 atoms of an element with different number of neutrons

applications of radioactive isotopes

dating fossils, tracing atoms through metabolic processes, diagnosing medical disorders

mass number

protons + neutrons

atomic number

of protons in the nucleus

subatomic particles

protons, neutrons, electron

proton's charge

positive charge.

neutron's charge

no charge

electron's charge

negative

electron's location in the nucleus

forms electron cloud around the nucleus

electron orbital

3d space where an electron is mostly found. each electron shell consists of a specific # of oribtals

these 2 subatomic particles are found in the nucleus

protons, neutrons

atoms

composed of subatomic particles. it is the smallest unit of matter that still retains the properties of an element.

compound

2 or more elements in a fixed ratio. its characteristics are different than its elements.

element

consist of unique atoms that can't be broken down to small substances.

matter

anything that takes up space and has mass. made up of elements

essential elements

25/92 elements are essential to life

essentail elements that make up 96% of living matter

carbon, hydrogen, oxygen, nitrogen

essentail elements that make up 4% of living matter

calcium, potassium, phosphorus, sulfur

trace elements

essentail elements required in minute quantities

covalent bond

sharing of a pair of valence electrons by 2 atoms, can be same or different elements. (count as part of atoms valence shell)

Hydrogen bond

forms when a hydrogen atom covalently bonded to one electronegative atom, is also attached to another electronegative atom

ionic bond

attraction between anion and cation

ionic compounds

compounds formed by ionic bonds

weak chemical bonds

ionic, hydrogen. reinforce shapes of large molecules and hep molecules adhere to each other.

Van der Waals interaction

if electrons are distributed asymmetrically in molecules or atoms, they can result in "hot spots" of positive or negative charge. As a result, strong attractions between molecules that are close together.

molecule

2+ atoms held together by covalent bond

molecular shape

determined by the positions of its atoms valence orbitals

molecular mass

sum of all the masses of all atoms in a molecule, measured in moles

molarity

number of moles of solute per liter in solution

molecular formula

used to represent atoms and bonding. ex H-H

single bond

sharing of one pair of valence electrons

double bond

sharing of two pairs of valence electrons

chemical reactions

making and breaking of chemical bonds. reversible.

starting molecules in a chemical reaction

reactants

final molecules in a chemical reaction

products

solution

solvent and solute

chemical equilibrium

forward and reverse reaction rates are equal

discovery science

observe and describe to create reasoning then come to a solution.

hypothesis based science

based on observations. create hypotheses. test prediction if hypothesis is true.

genome

an organism's complete set of DNA including all genes.

DNA function

controls development and maintenance of organism, transcribes into RNA which is translated into protein, inherited by offspring to parent

DNA structure

made up of 2 long chains arranged in a double helix. each link of a chain is 1 of 4 kinds of chemical blocks called nucleotides

genes

unit of inheritance that transmit information from parents to offspring. controls protein production indirectly.

prokaryotic cell

smaller. no nucleus or other membrane enclosed organelles.

types of prokaryotic cells

bacteria and archaea

eukaryotic cell

membrane enclosed in organelles such as the nucleus.

types of eukaryotic cells

plants, animals, fungi and all other forms of life

cells

organisms basic unit of structure. lowest level of organization that can preform all actives required for life.

structure of a cell

contains enclosed membrane and DNA

levels at which we study life

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

actives required for life

reproduction, response to stimuli, cells ability to divide, adaptation, growth, metabolism, organization, homeostasis

cells ability to divide

is the basis of reproduction. growth, and repair

reproduction

ability to produce individual organisms either asexually or sexually.

response to stimuli

contraction of unicellular organisms, all senses of multicellular organisms. motion and chemotaxis

adaptation

the ability to change over a period of time in response to the environment - evolution

growth

maintenance of higher rate of anabolism than catabolism.

metabolism

transformation of energy by converting chemicals and energy into cellular components and decomposing organic matter.

organization

being structurally composed of 1 or more cells

homeostasis

regulation of the internal environment to maintain a constant state.

approaches to study biology

reductionist, emergent properties, systems biology

systems biology

constructs models for the dynamic behavior of whole biological systems

reductionism

reduction of complex systems to simpler components that are easier to study. ex: molecular structure of DNA

emergent properties

result from the arrangement and interaction of parts within a system. can be nonbiological.

organic compounds

carbon containing compounds

molecule with the extra proton

hydronium ion

hydronium symbol

H+

hydroxide ion

molecule that lost the proton

hydroxide symbol

OH-

Acid/bases

causes imbalance in H+ and OH- concentrations

acids

increases hydrogen ion concentration

base

reduces the hydrogen ion concentration by accepting H+ or providing OH-

PH

-log[h+]

in aqueous solutions at 25 degrees..

the product of OH- and H+ =10^-14

acid PH

less than 7

base PH

greater than 7

buffers

substances that minimize changes in concentration go H+ and OH- in a solution

the internal PH of most living things

PH7

hydration shell

when an ionic compound is dissolved in water, each ion is surrounded by a sphere of water molecules

colloid

stable suspension of fine particles in a liquid

hydrophilic

substance that likes water

hydrophobic

does not have an affinity for water (oil, non-polar)

why does ice float?

because hydrogen bonds in ice are more ordered, making ice less dense

greatest density of water

4 degrees Celsius

what would happen if ice sank?

all bodies of water would freeze, making life impossible on earth.

evaporative cooling

liquid evaporates, remaining surface cools

function of evaporative cooling

helps stabilize temperatures in organisms and bodies of water

heat of evaporation

the heat a liquid must absorb for 1g to be converted to gas

high specific heat

amount of heat that must be absorbed or lost for 1g of that substance to change its temp by 1 degree celsius