Element - cannot be broken down to other substances by chemical reactions 

Compound - substance containing 2 or more elements combined

Trace Elements - required by an organism in very small quantities 

Proton (positive)

Neutron (neutral)

Electron (negative)

Atomic Number - # of protons

Atomic Mass - neutrons + protons

Isotope - same # of protons, different # of neutrons

Potential Energy - 

Valence Shell  (2,8,8)

Valence Electron - those in the valence (outer) shell

Valence Number - the number of unpaired electrons in the outer shell

Electronegativity - the attraction of an atom for electrons 

Nonpolar - equal sharing of electrons

Polar - unequal sharing of electrons (e-) 

Ionic bond - one atom is much more electronegative that it actually takes away an electron

Anion - negative 

Cation - positive

Hydrogen bonds - weak attraction between two polar molecules

Equilibrium - forward and reverse reaction are happening at the same rate

Hydrophobic - water hating

Hydrophilic - water loving 

Hydrocarbons - molecules made up of just carbon-hydrogen chains

Hydroxyl - (-OH) Alcohol

Carbonyl - (-C=O) Sugar

Carboxyl - (-COOH) Carboxylic Acid

Amino - (-NH2) Amines

Sulfhydryl - (-SH) Thiols

Phosphate (-OPO3) Phosphates

Polymer - long molecule made up of identical or very similar building blocks

Monomer - the building blocks

Dehydration synthesis - the process that joins monomers together (H2O is removed)

Hydrolysis - The process that breaks monomers apart (H2O is added)

Polypeptides - made of monomers called amino acids (these make up proteins)

Peptide Bonds - bonds found in polypeptides

Primary Structure 0 the sequence of amino acids

Secondary Structure - coils called alpha helices and folds called beta sheets (result of hydrogen bonding)

Tertiary Structure - the polypeptide continues to fold and change shape 

Quaternary - multiple polypeptides combine

Chaperonins - special proteins that help polypeptides to fold into shape

Protein Denaturation - when the protein changes shape and becomes inactive

Monosaccharides - simple sugars that have formulas in multiples of CH20 (example is glucose, fructose)

Carbohydrates - contains sugars and their polymers

Disaccharides - double sugars (example is sucrose (which is glucose and fructose)

Starch - energy storage in plants

Glycogen - energy storage in animals 

Cellulose - used for building plant cell walls

Lipids - do not include polymers, hydrophobic

Fats (triacylglycerol) - glycerol molecule and three fatty acids, linked with ester linkages (covalent) 

Saturated Fats - all single bonds, maximum hydrogens, linear (solid at room temperature) (source: animal fats)

Unsaturated Fats - At least 1 double bond, less than maximum hydrogens, bent (liquid at room temperature) (source: plants and fish oils)

Phospholipids - one phosphate, on glycerol, two fatty acids (polar head and nonpolar tail)

Cholesterol - helps with membrane stability (not too fluid, not too viscous) 
Hydrophobic - water hating

Hydrophilic - water loving

Amphipathic molecule - has both a hydrophobic and hydrophilic region

Selective Permeability -  some substances are allowed to cross the membrane; others are not

Membrane Fluidity - held together by hydrophobic interactions

Integral proteins - extend into the hydrophobic core

Transmembrane Proteins - cross the entire membrane

Peripheral Proteins - loosely attached to the surface of the membrane (polar or ionic)

Cell to Cell Recognition - the ability of a cell to distinguish one cell type from another

Oligosaccharides - (short polysaccharides) are attached as glycolipids or glycoproteins

Transport Proteins - transport specific substances across the membrane 

Diffusion - tendency of molecules to spread out (high conc. → low conc.)

Passive transport - diffusion across a biological membrane

Hypertonic - higher total concentration of solute, lower concentration of free H2O

Hypotonic - lower total concentration of solute, higher concentration of free H2O

Isotonic - equal concentrations 

Osmoregulation - control of water balance

Facilitated Diffusion - diffusion with the help of transport proteins 

Aquaporins - H20 channel proteins 

Gated Channel - something stimulates them to open

Active Transport - requires ATP, goes from low conc → high conc, sodium potassium pumps, electrogenic pumps, and proton pumps transport protein required

Exocytosis - release of macromolecules from the cell 

Endocytosis - cell takes in macromolecules by forming new vesicles from plasma membrane 

Phagocytosis - take in macromolecules 

Pinocytosis - take in extracellular fluid 

Receptor-mediated - recognition of a specific molecule triggers transport of bulk quantities of specific substances

Kinetic Energy - energy of motion

Potential Energy - energy that is stored due to location or structure

Chemical Energy - potential energy available for release in a chemical reaction

Free Energy - the amount of energy that can perform work 

Exergonic - energy is released, reacts spontaneously

Endergonic - energy is absorbed, isn’t spontaneous 

1st Law of Thermodynamics - Energy can be transferred and transformed, but it cannot be created or destroyed

2nd Law of Thermodynamics - energy transfer or transformation increases the entropy of the universe

Metabolism - the sum of all chemical reactions in an organism

Catabolic Pathways - breakdown complex molecules into simpler compounds producing a net release of energy 

Anabolic Pathways - build complex molecules from simpler ones, requiring a net input of energy

Energy Coupling - the energy released from the downhill reactions of catabolism can be stored and then used to drive the uphill reactions of anabolism

ATP (adenosine triphosphate) - The molecules that provides energy for most cellular work, the phosphate tail is very unstable because of negative charges

Activation Energy - the amount of energy required to start a reaction 

Competitive INhibitor - takes the place of the substrate

Non Competitive Inhibitor - changes the shape of the enzyme and doesn’t allow the subtract to enter the active site

Feedback Inhibition - the switching off of a metabolic pathway by its end product

Fermentation - Partial breakdown without oxygen

Cellular Respiration - more efficient pathway that requires oxygen

Oxidation - loss of an electron, electron donor, reducing agent

Reduction - the gain of an electron, electron acceptor, oxidizing agent

NADH - stored energy that can be used to make ATP, carries electrons to the electron transport chain

Glycolysis - Takes place in cytosol, breaks glucose into pyruvate 

Citric Acid Cycle (Krebs Cycyle) - takes place in mitochondria

Electron Transport Chain - In mitochondria, uses energy from electrons to make ATP

Chemiosmosis - using the potential energy of the H+ gradient to make ATP

Oxidative Phosphorylation - using energy from electrons from glucose

Photosynthesis - conversion of light energy to chemical energy

Autotrophs - produce organic molcules from CO2 and other inorganic raw materials (producers)

Heterotrophs - live on compounds produced by other organisms (consumers)

Chloroplast - use light energy to make glucose 

Mitochondrion - break glucose into ATP

Chlorophyll - the primary pigment in plants

Mesophyll - interior tissue of the leaf where most chloroplasts are found

Stomata - openings in the leaf that allow CO2 to enter and O2 to exit

Light reactions - convert light energy to chemical energy 

Photophosphorylation - ATP made

Calvin Cycle - (dark reactions)

Carbon Fications - incorporations of carbon from CO2 into organic molecules in the chloroplast 

Light - in the form of electromagnetic waves

Wavelength - distance between crests of light waves

Electromagnetic Spectrum - 380-750 nm (visible light)

Pigments - substances that absorb visible light

Spectrophotometer - instrument to measure which wavelengths of light are being transmitted (not absorbed) 

Chlorophyll A - primary pigment in photosynthesis (absorbs red and blue)

Accessory pigments - can absorb light and transfer energy to chlorophyll A

Carotenoids - yellow and orange 

Chlorophyll B - yellow green

Photo protection - absorb and dissipate excessive light that might damage chlorophyll

Light harvesting complex - cluster of pigment molecules 

Photosystem I - contains a p700 chlorophyll a (works with photosystem 2 to generate ATP and NADPH)

Photosystem II - contains a p680 chlorophyll a (works with photosystem 1 to generate ATP and NADPH)

Autocrine - a cell sends a signal to itself

Juxtacrine - a cell sends a signal to a connecting cell 

Paracrine - a cell sends a signal to a nearby cell

Endocrine - signal travels as a hormone to seperate parts of the body

Reception - target cell detects and external signal, ligand binds to receptor protein and changes the shape

Transduction - usually a multi-step relay

Response - any cellular response 

Protein kinase - any enzyme that transfers a phosphate from ATP to a protein

Protein phosphatases - remove the phosphate groups 

Apoptosis - programmed cell death, used by sick, old, or damaged cells
Conformer - allows it internal condition to change along with external changes

Regulator - uses homeostasis to control the internal environment (even if there is external fluctuation)

Homeostasis - steady internal stability

Set point (feedback system) - the particular value maintained for an internal variable

Stimulus (feedback system) - a fluctuation in the variable above or below the set point

Sensor (feedback system) - detects the stimulus

Control Center (feedback system) - processes information from the sensor and directs an appropriate response

Effector (feedback system) - carries out the response

Negative Feedback - control center counteracts further change in the same direction

Positive Feedback - control center will amplify the variable 

Ectotherm - metabolic rate is so low that the amount of body heat generated has little effect on body temperature

Endotherm - metabolic rate is high so enough body heat is generated to maintain a higher body temperature

Vasodilation - widening of blood vessels near the surface

Vasoconstriction - narrowing of blood vessels near the surface

Hypothalamus - sensors for thermoregulation are here

Phototropism - plant growth in response to light 

Photoperiodism - response of plants to lengths of light and dark periods

Circadian rhythm - physiological cycles with a frequency of about 24 hours that are not directly paced by an environmental variable

Cell body - contains the nucleus and most other organelles

Dendrites - branched extensions that receive signals

Axon - long extension that send signals

Synapse - the junction between the sending cell and the receiving cell

Postsynaptic cell - another neuron, muscle, or gland

Resting Potential - membrane potential of an unstimulated neuron

Depolarization - Na+ rushes into axon and inside because more positively charged

Action potential - all sodium channels open

Repolarization - return to resting state

Myelin sheath - electrical insulation surrounding vertebrate axons 

Innate Barriers - fast, non specific

Adaptive Barriers - slow, specific 

Antigen - a piece of a pathogen that triggers a specific immune response

Phagocytes - macrophages, neutrophils, dendritic cells

Macrophages - migrate through body tissues

Neutrophils - circulate in blood, will leave blood and go to infected area

Dendritic Cells - stimulate adaptive immunity

Lymphocytes - Natural Killer cells, T Cells, B Cells

Humoral Immunity - B cells make antibodies which attach to pathogens and interfere with function

Cell Mediated Immunity - T Cells targets pathogens inside infected body cells (responds to cancer cells and transplanted tissue)

Meiosis - produces gametes

Mitosis - produces somatic cells

Chromosome - tightly packed DNA, condisters of a single DNA molecule with associated proteins

Chromatin - lightly coiled DNA

Kinetichore - where the spindle fibers attach

Interphase - G1, S, G2

G1 Phase (cell cycle) - cell growth

S Phase (cell cycle) - DNA replication

G2 Phase (cell cycle) - organelle and protein synthesis preparation for cell division

Prophase - chromatin because chromosomes and centrosomes move to poles, spindle fibers attach to kinetochores

Metaphase - kinetochore microtubules align chromosomes at equator

Anaphase - kinetochore microtubules separate chromosomes, non kinetochore microtubules elongate cell

Telophase - chromosomes go back to chromatin

Cytokinesis - cell splits in half 

Cell Cycle Control System - composed of the molecules in the cell that regulate the progression of the cell cycle

Kinase - an enzyme that activates or inactivates other proteins by phosphorylating them

Cyclin Dependent Kinases - kinases that must be attached to cyclin to be active

Cell Cycle Checkpoint - a control point during the cell cycle with stop or go ahead signals

Animal Cells Checkpoints - built in stop signals until overridden by go-ahead signals 

G1 checkpoint - restriction point, Go → continue the cell cycle, Stop → G0 phase

MPF (M phase promoting factor) - a cyclin CDK complex that triggers a cells passage past the G2 checkpoint

Growth Factor - protein released by certain body cells that trigger other cells to divide 

Density Dependent Inhibition - crowded cells stop dividing

Anchorage Dependence - must be attached to something to divide 

Transformation (cancer) - a single cell becomes a cancer cell (normally destroyed by body's immune system)

Tumor - a mass of cells that forms from the original transformed (cancer) cell

Benign Tumor - a tumor that remains in the original site

Malignant tumor - a tumor that becomes invasive and impairs functioning of healthy tissue → cancer

Metastasis - spread of cancer cells to other parts of the body

Radiation - targeted 

Chemotherapy - contains toxic drugs that target rapidly dividing cells

Gene - a segment of DNA that codes for a certain trait

Haploid Cell - one set of chromosomes 

Diploid Cell - two sets of chromosomes

Sex chromosomes - pair #23

Autosomes - pairs #1-#22

Homologous Chromosomes - pairs of chromosomes with genes for the same traits (1 maternal, 1 paternal)

Interphase (meisosis) - DNA replication occurs

Meiosis 1 - diploid cells with double chromosomes divides into two haploid cells with double chromosomes

Meiosis 2 - two haploid cells with double chromosomes divide into frou haploid cells with single chromosomes

Crossing Over - a portion of nonsiter chromatids switch places

Independent Assortment of Chromosomes - the gamete that a chromosome ends up in is completely random

Random Fertilization - over 70 trillion possible zygotes

Law of Dominance - dominant alleles will show and the recessive won’t

Law of Segregation - when the homologous pair separate during meiosis 1 , that separates the gene pair

Law of Independent Assortment - different traits seem to be inherited independently of each other

Chromosome Theory of Inheritance - genes have a specific loci on chromosomes

Sex-linkage - most sex-linked traits are x-linked because the x is larger than the Y

X inactivation - only occurs in females, only one X chromosome in each cell is active in each cell

Linked Genes - genes located on the same chromosome are linked genes

Parental - phenotype same as parents

Recombinant - new gene combinations (unlike parents)

Genetic Map - an ordered list of genetic loci along a chromosome

Linkage Map - a type of genetic map based on recombination frequencies

Map unit - distance between genes

Nondisjunction - error during meiosis, homologous pairs don’t separate properly during anaphase 1

Aneuploidy - offspring with an abnormal number of chromosomes

Trisomic - an organism with three copies of a chromosome (down syndrome)

Monosomic - an organism with one copy of a chromosome

Polyploidy - more than two complete sets of chromosomes 

Deletion - chromosome fragment is lost during cell division 

Duplication - the lost portion is attached to the sister chromatid

Inversion - the lost portion is reattach debut in the opposite orientation

Translocation - the lost portion is attached to a different chromosome

Pedigree - a family tree showing genetic relationships for a particular trait

Rule of Multiplication - the likelihood of two events happening together 

Rule of Addition - an event can occur in more than one way

Semiconservative Model - each new DNA molecule has one parent strand and one new strand

Origins of Replication - sites along the DNA molecule where replication begins

Helicase - the enzyme that untwists and unzips the double helix (breaks hydrogen bonds)

Topoisomerase - works ahead of helicase to relieve “supercoiling”

DNA Polymerase - the enzyme that catalyzes elongation of DNA (bonds the free nucleotide to the backbone

Primase - joined the RNA nucleotides together to make the primer

Leading Strand - continuous replication

Lagging Strand - replication occurs in sections

Okazaki fragment - sections of the lagging strand, joined together by an enzyme called DNA ligase

DNA ligase - connects Okazaki fragments

Nuclease - cuts DNA and takes out damaged section

Telomeres - region of DNA at the end of a chromosome

Telomerase - an enzyme that lengthens the telomeres

Gene - a section of DNA that can be expressed to produce either a polypeptide or and RNA molecule

Transcription - DNA to mRNA

Translation - mRNA to polypeptide 

Reading Frame - bases are read as sequential groups of three

Start Codon - determines where translation begins

Stop Codon - terminates translation

RNA Polymerase - separates the two strands of DNA

Transcription unit - the section of DNA that is transcribed into an mRNA molecule

Coding Strand - same code as mRNA

Template Strand - the strand that mRNA matches up to (has the promoter)

Initiation (transcription) - promoter tells RNA polymerase where to begin

Transcription factors - proteins that help RNA polymerase bind to the DNA and initiate transcription

Elongation (transcription) - RNA polymerase connects RNA nucleotides to make mRNA 

Termination (transcription) - terminator sequence tells RNA polymerase where to stop

Alternative RNA splicing - some genes can make more than one polypeptide, depending on which sections are treated as introns or exons

Introns - removed sections of DNA

Exons - expressed sections of DNA

tRNA - transfer RNA (the interpreter)

Ribosomes - made of protein and ribosomal RNA (small and large subunits)

Initiation (translation) - small subunit binds to mRNA 

Elongation (translation) - base pairing between mRNA codons and tRNA anticodons

Termination (translation) - elongation continues until a stop codon

Point mutation - a change in just one nucleotide pair of a gene

Substitution - changes one nucleotide pair

Insertion - adds a nucleotide pair

Deletion - removes a nucleotide pair

Silent mutation - does not affect amino acid sequence

Missense mutation - codes for one wrong amino acid

Frameshift mutation - shifts the reading frame 

Nonsense mutation - codon changes to a stop codon

Spontaneous mutations - eros in DNA replication or DNA repair

Mutagens - physical or chemical agents that cause mutation in DNA

Histone Acetylation - attachment of acetyl groups to histone proteins, promotes transcription

DNA methylation - attachment of methyl groups to DNA bases, inhibits transcription

Control Elements - segments of noncoding DNA that serve as binding sites for transcription factors

Activator - bind to enhancer, helps general transcription factors and RNA polymerase assemble

Repressor - binds to silencer, blocks general transcription factors and RNA polymerase

Differentiation - the process by which cells become specialized in structure and function

Cytoplasmic determinants - maternal molecules in the cytoplasm of the egg

Induction - changes made to target cells by signal molecules

Operons - a group of related genes under the control of a single promoter

Repressible operons - usually on but can be turned off

Inducible operon - usually off but can be turned on

Gene cloning- multiple copies of a gene

Restriction Enzymes - cut DNA molecules at specific locations 

Recombinant DNA - DNA from two different sources combined in one molecule 

Restriction Site - the specific sequence that is recognized by the restriction enzyme 

PCR (polymerase chain reaction) - a piece of DNA is quickly copied without using cells (in vitro)

Gel Electrophoresis - Separates macromolecules based on size and/or charge

Genetic Profile - a pattern of bands specific to a person 

Restriction Fragment Length Polymorphisms - differences in DNA sequences 

CRISPR - a way to precisely edit DNA

GMO - any organism whose genetic material has been altered using genetic engineering techniques

Transgenic - the genetic material has been altered by the addition of genetic material from an unrelated organism 

Microevolution - genetic changes in populations over time

Species - a group of similar organisms that can interbreed and produce fertile offspring

Population - a group of organisms of the same species living in the same area

Gene pool - all of the alleles in a population at any given time

Hardy-weinburg theorem - the gene pool of a non evolving population is in equilibrium 

Natural selection -popualtions can change over time if the more fit organisms leave more offspring than less fit organisms

Genetic drift - changes in populations allele frequencies due entirely to chance

Bottleneck effect - genetic drift due to a drastic reduction in population size

Founder effect - genetic drift in a new colony

Gene flow - genetic change due to the migration of fertile individuals or gametes between populations

Heterozygous advantage - example of sickle cell anemia

Neutral variation - no apparent selectional advantage or disadvantage

Fitness - measured by reproductive success 

Directional selection - most common during periods of change or when members of a population migrate to a new location

Diversifying selection - occurs when environmental conditions favor individuals on both extremes 

Stabilizing selection - acts against the extremes and favors the intermediate

Sexual selection - a type of natural selection in which mating preferences influence traits

Intersexual selection - individuals of one sex are choosy in selecting mates

Sexual dimorphism - differences in appearance between the sexes

Intrasexual selection - direct competition among individuals of one sex

Evolutionary adaptations - inherited characteristics that enhance survival and reproduction in specific environments

Adaptation - an advantageous, inherited trait that increases the chances of survival and reproduction

Artificial selection - humans select for desirable traits, causing change over time to a population 

Homologous structures - similar morphological features due to common ancestry

Vestigial structures - structures that are homologous to important structures, but have lost their major ancestral function

Fossil record - the age of a fossil can be estimated broadly by looking at the layer of rock in which it is found

Endosymbiotic theory - eukaryotic cells could have evolved from prokaryotic cells that lived in symbiosis 

Prokaryote symbiosis - the organisms lived together 

Taxonomy - ordering, classifying, naming, and diversity of life

Clades - group of ancestral species with their descendants

Taxa - groups of species 

Nodes - common ancestors

Phylogeny - evolutionary history of a species or group of species

Extinct - no longer living

Extinct - living

Homology - similarities resulting from common ancestry

Analogy - similarities due to convergent evolution (anatomically not similar, but similar function)

Cladistics - study of how species can be grouped into clades

Shared ancestral character - a character that originated in ancestor of the taxon

Shared derived character - an evolutionary novelty unique to the particular clade

Outgroup - a species or group of species that diverged before the lineage we are studying

Macroevolution - the origin of new taxonomic groups

Speciation - the origin of new species

Anagenes - transformation of one species into another

Cladogenesis - budding of one or more new species from a parent species that continues to exist

Reproductive isolation - reproductive barriers that prevent interbreeding between species 

Geographic isolation - separated by a physical barrier (mountain range, water, etc)

Habitat isolation - limits interact

Behavioral isolation - mating signals and rituals 

Temporal isolation - breeding occurs during different times of day, seasons, or years

Mechanical isolation - anatomy incompatible

Gametic isolation - even if the gametes meet, they rarely fuse to form a zygote

Reduced hybrid viability - genetic incompatibility may abort development

Reduced hybrid fertility - hybrid is sterile

Hybrid breakdown - hybrids are fertile, but when they mate with each other, their offsprings are feeble or sterile

Ecological species concept - a species is defined in terms of its niche (ecological role)

Morphological Concept - characterizes a species based on unique structural features

Pluralistic concept - the factors that unify members of a species vary 

Genealogical Concept - a species has a unique evolutionary history

Allopatric Speciation - occurs because two populations are separated in space

Sympatric Speciation - occurs in overlapping population

Adaptive Radiation - the emergence of numerous species from a common ancestor introduced into a new environment

Gradualism Tempo of Speciation - slow, steady change accumulates over long periods of time

Punctuated Equilibrium - long perdios of stability punctuated by spurts of relatively rapid change (speciation)

Ecology - study of interactions between organisms and their environment

Community - a group of populations of difference species in an area

Ecosystem - the community of organisms and the nonliving factors with which they interact

Biotic - living

Abiotic - nonliving

Semelparity - single opportunity to reproduce with many offspring

Iteroparity - living to reproduce repeatedly but fewer offspring with each event 

Exponential growth - population increase under ideal conditions (no constraints) (J shape curve)

Logistic Growth - shows the effect of population density on growth rate (constraints) (S shape curve)

Carrying Capacity - the maximum population size that the system can support 

Density Dependent Factors - have a greater impact as the population size increases

Density Independent Factor - a factor that affects populations in the same way, regardless of density (natural disasters)

Niche - a species ecological role 

Competition -  (-/-) two species cannot have the same niche in the same area and coexist

Predation - (+/-) relationship between species where one benefits and one doesn’t

Mutualism - (+/+) both species benefit

Commensalism - (+/=) benefits one species and the other is unaffected

Parasitism - (+/-) parasite gets nourishment from the host which is harmed

Autotroph - produces its own food by capturing physical or chemical energy 

Protosynthetic Autotroph - use light

Chemosynthetic Autotroph - use energy from chemical reactions to make food

Heterotroph - gets energy from other orgnaisms 

Biodiversity - the variety of species in an ecosystem

Keystone Species - have a great impact, not because of number, but of ecological niche

Invasive Species - causes ecological or economic harm in a new environment wheree it is not native

Trophic Cascade - when changes in one part of a tophic pyramid have an effect on other, sometime unrelated parts

Succession - the structure of a biological community changes over time

Primary succession - newly exposed rock is colonized for the first time

Secondary succession - an area with living things is disturbed and then recolonized

Primary productivity - the rate at which autotrophs produce organic compounds

Gross Primary productivity - the total amount of organic compounds produced 

Net Primary productivity - the amount of organic compounds remaining after plants use what they need 

Trophic efficiency - percentage biomass/energy transferred from one trophic level to the next (about 10%)

Nitrogen fixation - N2 is converted to nitrogen compounds