AP Biology: Big Idea 3 Flashcards

6716250187	Hershey-Chase Experiment	Experiment that showed that only the DNA enters a bacterial cell during infection, not protein by using radioactive S and P.	0
6716250188	Frederick Griffith	This person discovered transformation during an experiment that involved injecting mice with smooth S cells, rough R cells, heat-killed S cells, and heat-killed S cells with living R cells.	1
6716250189	Erwin Chargaff	Discovered that DNA composition varies, but the amount of adenine is always the same as thymine and the amount of cytosine is always the same as guanine.	2
6716250190	Avery, MacLeod, McCarty	Determined that DNA was Griffith's "Transforming Factor."	3
6716250191	Rosalind Franklin	Used X-ray diffraction to discover the double-helical structure of DNA.	4
6716250192	Watson and Crick	Developed the double helix model of DNA.	5
6716250193	nucleic acid	An organic compound, either RNA or DNA, whose molecules are made up of one or two chains of nucleotides and carry genetic information.	6
6716250194	nucleotide	Monomer of nucleic acids made up of a sugar, phosphate, base	7
6716250195	purines	Nitrogenous bases that have a double ring structure (AG)	8
6716250196	pyrimidines	Nitrogenous bases that have a single ring structure (CT)	9
6716250197	antiparallel	The opposite arrangement of the sugar-phosphate backbones in a DNA double helix.	10
6716250198	phosphodiester bond	Strong covalent bond linking the sugar in one nucleotide to the phosphate of another. (BACKBONE SEALER!)	11
6716250199	DNA replication	The process whereby DNA makes a copy of itself prior to cell division.	12
6716250200	semiconservative model	Type of DNA replication in which the replicated double helix consists of one old strand, derived from the old molecule, and one newly made strand.	13
6716250201	DNA polymerase	DNA replication enzyme that adds nucleotides in the 5 to 3 (as it reads in the 3 to 5)	14
6716250202	transcription	Synthesis of an RNA molecule from a DNA template.	15
6716250203	lagging strand	A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5' to 3' direction away from the replication fork.	16
6716250204	leading strand	The new continuous complementary DNA strand synthesized along the template strand in the mandatory 5' to 3' direction.	17
6716250205	primase	An enzyme that joins RNA nucleotides to make the primer using the parental DNA strand as a template.	18
6716250206	messenger RNA (mRNA)	Carries genetic message from the DNA to he protein-synthesizing machinery of the cell.	19
6716250207	Okazaki fragments	Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.	20
6716250208	DNA helicase	An enzyme that untwists the double helix at the replication forks, separating the two parental strands and making them available as template strands.	21
6716250209	translation	The synthesis of a polypeptide, which occurs under the direction of mRNA.	22
6716250210	RNA editing	The modification of mRNA before it leaves the nucleus that is unique to eukaryotes.	23
6716250211	codons	mRNA base triplets.	24
6716250212	RNA polymerase	Enzyme that links together the growing chain of ribonucleotides during transcription.	25
6716250213	promoter	A specific nucleotide sequence in DNA that binds RNA polymerase and indicates where to start transcribing mRNA.	26
6716250214	TATA box	Crucial promoter DNA sequence.	27
6716250215	RNA splicing	Process by which the introns are removed from RNA transcripts and the remaining exons are joined together.	28
6716250216	introns	Noncoding segments of nucleic acid that lie between coding sequences.	29
6716250217	exons	Coding segments of eukaryotic DNA.	30
6716250218	transfer RNA (tRNA)	Interpreter of a series of codons along a mRNA molecule.	31
6716250219	ribosomal RNA (rRNA)	RNA molecules that construct ribosomal subunits.	32
6716250220	ribosomal P site	Site that holds tRNA carrying the growing polypeptide chain. (PEPTIDE)	33
6716250221	ribosomal A site	Site that holds the tRNA carrying the next amino acid to be added to the chain. (ADD)	34
6716250222	ribosomal E site	Site where discharged tRNAs leave the ribosome. (EXIT)	35
6716250223	transformation	A change in genotype and phenotype due to the assimilation of external DNA by a cell.	36
6716250224	gene expression	Conversion of the information encoded in a gene first into messenger RNA and then to a protein.	37
6716250225	recombinant DNA	A DNA molecule made in vitro with segments from different sources.	38
6716250226	restriction enzyme	A degradative enzyme that recognizes and cuts up DNA (including that of certain phages) that is foreign to a bacterium.	39
6716250227	DNA ligase	A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain.	40
6716250228	denaturation	In proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive. In DNA, the separation of the two strands of the double helix.	41
6716250229	polymerase chain reaction (PCR)	A technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.	42
6716250230	gel electrophoresis	The separation of nucleic acids or proteins, on the basis of their size and electrical charge, by measuring their rate of movement through an electrical field in a gel.	43
6716250231	plasmid	Small extra-chromosomal, double-stranded circular DNA molecules.	44
6716250232	RNA primer	Short segment of RNA used to initiate synthesis of a new strand of DNA during replication.	45
6716250233	reverse transcriptase	A polymerase that catalyzes the formation of DNA using RNA as a template.	46
6716250234	somatic cell	Any of the cells of a plant or animal except the reproductive cells.	47
6716250235	centromere	The region of the chromosome that holds the two sister chromatids together during mitosis.	48
6716250236	mitosis	Cell division in which the nucleus divides into nuclei containing the same number of chromosomes.	49
6716250237	interphase	Period of the cell cycle between cell divisions.	50
6716250238	S phase	The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.	51
6716250239	cancer	Disease that results from disruptions of cell cycle control.	52
6716250240	kinetochore microtubules	Connects the centrosome with the kinetochore in the centromere region of the chromosome.	53
6716250241	growth factors	Regulatory proteins that ensure that the events of cell division occur in the proper sequence and at the correct rate.	54
6716250242	allele	One of the alternative forms of a gene that governs a characteristic, such as hair color.	55
6716250243	crossing over	Nonsister chromatids exchanging DNA segments.	56
6716250244	diploid cell	Has two sets of chromosomes.	57
6716250245	fertilization	Union of gametes.	58
6716250246	gametes	A haploid cell such as an egg or sperm that unite during sexual reproduction to produce a diploid zygote.	59
6716250247	genes	Units of heredity made up of DNA.	60
6716250248	haploid	One set of chromosomes.	61
6716250249	homologous chromosomes	Pair of chromosomes that are the same size, same appearance and same genes.	62
6716250250	zygote	Fertilized egg; carries one set of chromosomes from each parent.	63
6716250251	law of independent assortment	The random distribution of the pairs of genes on different chromosomes to the gametes.	64
6716250252	law of segregation	Allele pairs separate or segregate during gamete formation, and randomly unite at fertilization. Due to separation of homologous chromosomes in Meiosis I.	65
6716250253	true-breeding	Organisms that, when reproducing, create offspring of all the same variety.	66
6716250254	hybridization	The crossing of two different true-breeding parents.	67
6716250255	dominant allele	An allele whose trait always shows up in the organism when the allele is present.	68
6716250256	recessive allele	An allele that is masked when a dominant allele is present	69
6716250257	homozygous	An organism having a pair of identical alleles for a character, either dominant or recessive.	70
6716250258	phenotype	An organism's traits.	71
6716250259	genotype	An organism's genetic makeup.	72
6716250260	codominance	When which the phenotypes of both alleles are exhibited in the heterozygote.	73
6716250261	incomplete dominance	Creates a blended phenotype; one allele is not completely dominant over the other.	74
6716250262	nondisjunction	A failure of paired homologous chromosomes to separate during meiosis which results in an abnormal chromosome number.	75
6716250263	linked genes	Genes located on the same chromosome that tend to be inherited together in genetic crosses.	76
6716250264	sex linked genes	Genes located on the sex chromosomes.	77
6716250265	operon	A unit of genetic function common in bacteria and phages, consisting of coordinately regulated clusters of genes with related functions.	78
6716250266	operator	Region of DNA that controls RNA polymerase's access to a set of genes with related functions.	79
6716250267	repressor	A protein that suppresses the transcription of a gene.	80
6716250268	Trp operon	An example of a repressible operon.	81
6716250269	Lac operon	An example of an inducible operon.	82
6716250270	transcription factors	Proteins that bind to specific DNA sequences or other regulatory proteins that promote or block RNA polymerase.	83
6716250271	hormones	Circulating chemical signals that are formed in specialized cells, travel in body fluids, and act on specific target cells.	84
6716250272	ligand	A molecule that specifically binds to another molecule, often a larger one.	85
6716250273	protein kinase	The enzyme that transfers phosphate groups from ATP to protein.	86
6716250274	reception	The target cell's detection of a signal molecule coming from outside the cell.	87
6716250275	transduction	The binding of the signal molecule changes the receptor protein in some way.	88
6716250276	response	The transduced signal finally triggers a specific cellular response.	89
6716250277	endocrine signaling	Type of cell signalling where signals released by one cell type can travel long distances to target cells of another cell type.	90
6716250278	cell body (soma)	Contains most of a neuron's organelles and its nucleus.	91
6716250279	dendrites	highly branched extensions that receive signals from other neurons	92
6716250280	axon	Long nerve fiber that conducts away from the cell body of the neuron.	93
6716250281	synapse	The junction between two neurons or between a neuron and a muscle.	94
6716250282	neurotransmitters	Chemical messengers that cross the synaptic gaps between neurons.	95
6716250283	membrane potential	The voltage across a cell's plasma membrane.	96
6716250284	resting potential	The membrane potential of a neuron that is at rest.	97
6716250285	depolarization	The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.	98
6716250286	voltage-gated ion channels	Channels that open or close in response to a change in the membrane potential.	99
6716250287	action potential	A neural impulse; a brief electrical charge that travels down an axon.	100
6716250288	repolarization	Return of the cell to resting state, caused by reentry of potassium into the cell while sodium exits the cell.	101
6716250289	threshold	The minimum membrane potential that must be reached in order for an action potential to be generated.	102
6716250290	myelin sheath	A layer of electrical insulation that surrounds the axon.	103
6716250291	sodium-potassium pump	a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell.	104
6716250292	point mutation	A mutation that affects a single nucleotide, usually by substituting one nucleotide for another.	105
6716250293	frameshift mutation	Mutation that shifts the "reading frame" of the genetic message by the insertion or deletion of a nucleotide.	106
6716250294	bacteriophage	A virus that infects and replicates within bacteria.	107
6716250295	lytic cycle	Viral life cycle in which the viral DNA exists as a separate molecule within the bacterial cell. Results in the destruction of the infected cell.	108
6716250296	lysogenic cycle	Viral life cycle characterized by integration of the viral nucleic acid into the host bacterium's genome. The viral genetic material can be transmitted to daughter cells.	109