Biology Terms and Definitions One

clairebear2018's version from 2018-02-01 15:18

Section 1

Question Answer
Organisms are composed ofmatter - matter is everything that takes up space and has mass
Essential Elements about 20-25% of the 92 natural elements are required for life
Trace Elements are required by an organism in only minute quantities
Atomic Number the number of protons in a nucleus
Mass Numberthe sums of protons plus neutrons in a nucleus
Atomic Massthe atoms total mass, can be approximated by the mass number
Isotopestwo atoms of an element that differ in number of neutrons
Radioactive Isotopes decay spontaneously, giving of particles and energy
Half Lifea parent isotope decays into its daughter isotope at a fixed rate - vary from seconds or days to billions of years
Radiometric Datingscientists measure the ratio of different isotopes and calculate how many half lives have passed since the fossil or rock was formed
Energythe capacity to cause change
Potential Energythe energy that matter has because of its location or structure - electrons of an atom differ in their amounts
Electron Shellan electrons state of potential energy is called its energy level or...
Chemical Bonds these interactions usually results in atoms staying close together, held be attractions called...

Section 2

Question Answer
Moleculeconsists of two or more atoms held together by covalent bonds
Single Bondthe sharing of one pair of valence electrons
Double Bondthe sharing of to pairs of valence electrons
Electronegativity an atoms attractive for the electrons in a covalent bond
Non Polar Covalent Bondthe atoms share the electron equally
Polar Covalent Bondone atom is more electronegative, and the atoms to not share the electron equally - the electrons of this bond spend more time near the oxygen than the hydrogen
Cation positively charged ion
Anion negatively charged ion
Ionic Bond attraction between a cation and an anion
Ionic Compounds (or) Saltscompounds formed by ionic bonds
Hydrogen Bondforms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to an electronegative atom
Van Der Waals Interactionattractions between molecules that are close together as a result of these charges
Chemical Reactions the making and breaking of chemical bonds
Reactants the starting molecules of a chemical reaction
Products the final molecules of a chemical reaction

Section 3

Question Answer
Polar Moleculewater molecule - charge is unevenly distributed - polarity allows water molecules to form hydrogen bonds with each other
Cohesion collectively, hydrogen bonds hold water molecules together, a phenomenon called....
Adhesion an attraction between different substances, for example, between water and plant cell walls
Surface Tensionmeasure of how difficult it is to break the surface of a liquid, water has an unusually high surface tension due to hydrogen bonding
Kinetic Energythe energy of motion
Thermal Energykinetic energy associated with random motion of atoms or molecules in a body of matter
Temperaturerepresents the average kinetic energy of the molecules in a body of matter
Heatthermal energy in transfer from one body to another
Calorie (Cal)the amount of heat required to raise the temperature of 1g of water by 1 degree C, also the amount of heat released when 1g of water cools 1 degree C
Kilocalories (KCal)the calories on food packages are actually .... 1 - KCal = 1000 Cal
Joule (J) another unit of energy .... 1 J = 0.239 cal or 1 cal = 4.184 J
Specific Heatthe amount of heat that must be absorbed or lost for 1g of that substance to change its temperature by 1 degree C
Heat of Vaporization the heat of a liquid must absorb for 1g to be converted to gas
Evaporative Coolingas a liquid evaporates, its remaining surface cools

Section 4

Question Answer
Solutiona liquid that us a completely homogeneous mixture of substances
Solventdissolving agent of a solution
Solutethe substance that is disolved
Aqueous Solutionone is which water is the solvent
Hydration Shellwhen an ionic compound is dissolved is water, each ion is surrounded by a sphere of water molecules called a ...
Hydrophillicsubstance is one that has an affinity for water
Hydrophobicsubstance is one that does not have an affinity for water
Molecular Massis the sum of all masses of all atoms in a molecule
Mole (mol)= 6.02 x10^23 molecules
Molarity (m) is the number of moles of solute per liter of solution
Avagdro's Numberthe unit Dalton were defined such that 6.02x10^23 daltons = 1g
Hydrogen Ionthe hydrogen atom leaves its electron behind and is transferred as a proton or....
Hydroxide Ionthe molecule that lost the proton is now a ....
'Hydronium Ion the molecule with the extra proton is now a ..... (H3O+)
Bufferssubstances that minimize changes in concentrations of H+ and OH- in a solution
Interal PHmost living cells is 7

Section 5

Question Answer
Ocean AcidificationCO2 dissolved in seawater forms carbonic acid ; this process is called ....
Organic Chemistrythe study of compounds that contain carbon , regardless of origin, range from simple molecules to colossal ones
Valencethe number of unpaired electrons in the ... shell of an atom is generally equal to its .... , the number of covalent bonds it can form
Hydrocarbonsorganic molecules consisting of only carbon and hydrogen
Isomers compounds with the same molecular formula but different structures and properties
Structural Isomersdifferent covalent arrangements of their atoms
Cis-Trans Isomershave the same colvalent bonds but differ in their spatial arrangements
Enantiomersisomers that mirror images of each other
Adenosine Triosphate (ATP) an important organic phosphate - attached to a string of 3 phosphate groups
PhosphateO-O-P-O-O Energy production - period table #15
CarbonylC=O Alcohol / Sugar, aldehydes and ketones, polar
HydroxylOH Alcohol / Sugar, polar
AminoNH2 Can also include carbon and oxygen Proteins
SulfhydrylSH2, thiols, helps stabylize the structure of proteins
CarboxylCOOH acidic due to lack of H+

Section 6

Question Answer
Valence Electrons in Carbon+/- 4
Valence Electrons in Oxygen-2
Valence Electrons in Hydrogen+1
Valence Electrons in Chlorine-1
Valence Electrons in Nitrogen+5
Scientic Methodobservation, problem, hypothesis, experiment, conclusion
Which of the following is a trait NOT associated with hydrogen bonds between water moleculestemperature modification by water molecules
Cholesterol is composed primarily of carbon and hydrogen atoms. Therefore, one would expect cholesterol to beinsoluble in water
Glucose and Fructose structures differ in thearrangement of carbon, hydrogen and oxygen atoms
A group of molecular biologists is tring to synthesize a new artificial compound to mimic the effects of a known hormone that influences sexual behavior, they have turned to you for advice. What is most likely to mimic the effects of the hormone?a compound with the same 3D shape as part of the hormone
Number of bonds to complete the octetFor nitrogen, 8-5=3. For oxygen, 8-6=2. Hydrogen, 2-1=1. Carbon, 8-4=4

Section 7

Question Answer
How many neutrons does hydrogen, as shown on the periodic table, have?0.008
How many neutrons does carbon, as shown on the periodic table, have?6.01
How many neutrons does carbon, with an atomic mass of 14 have?8.01
How many electrons does chlorine, as shown on the periodic table, have?17
How many electrons does Cl have?18
Metal lose/gain electrons and become anions/cationslose, cations
According to the octet rule, how many electrons may the third energy level contain?10
What is the atomic number of bromine?35
What is the atomic mass of calcium?40.08

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