Biology Campbell 9th Edition Chapter 16 and 17 Flashcards

1036383637	2 DNA strands are held together by....	Hydrogen bonds between nitrogenous bases	1
1036383638	pairs of nitrogenous bases in DNA double helix are held together by....	Hydrogen bonds	2
1036383639	First step in basic DNA replication	strands separate, each parental strand serves as a template that determines the order of nucleotides along a new complementary strand	3
1036383640	Second step in basic DNA replication	complementary nucleotides line up and and connect to sugar-phosphate backbones of the new strands. Each strand consists of 1 parent strand, 1 daughter strand	4
1036383641	Conservation Model of DNA replication	2 parental strands reassociate after acting as templates for new strands, thus restoring the parental double helix	5
1036383642	Semiconservative Model of DNA replication	2 strands of the parental molecule separate, and each functions as a template for synthesis of a new, complementary strand	6
1036383643	Dispersive Model of DNA replication	Each strand of both daughter molecules contain a mixture of old and newly synthesized DNA	7
1036383644	Replication Fork	Y shaped region where parental strands of DNA are being unwound	8
1036383645	Helicases	Enzymes that unwinds and separates the parental DNA strands to become template strands	9
1036383646	Single-strand binding proteins	bind to unpaired DNA strands, stabilize unwound parent strands	10
1036383647	Primase	Synthesizes the primer Starts a complementary RNA chain from a single RNA nucleotide adding RNA nucleotides one at a time, using the parental DNA strand as a template	11
1036383648	DNA polymerases	Catalyze the synthesis of new DNA by adding nucleotides to a preexisting chain Require a primer and DNA template strand	12
1036383649	Leading strand	The new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5' to 3' direction	13
1036383650	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	14
1036383651	Okazaki fragments	A short segment of DNA synthesized away from the replication fork on a template strand during DNA replication. Many such segments are joined together to make up the lagging strand of newly synthesized DNA	15
1036383652	Synthesis of lagging strand Step 1	Primase joins RNA nucleotides into primer	16
1036383653	Synthesis of lagging strand Step 2	DNA pol II adds DNA nucleotides to the primer, forming Okazaki fragment 1	17
1036383654	Synthesis of lagging strand Step 3	After reaching the next RNA primer to the right, DNA pol III detaches	18
1036383655	Synthesis of lagging strand Step 4	Fragment 2 is primed, Then DNA pol III adds DNA nucleotides, detatching when it reaches the fragment 1 primer	19
1036383656	Synthesis of lagging strand Step 5	DNA pol I replaces the RNA with DNA, adding to the 3' end of fragment 2	20
1036383657	Synthesis of lagging strand Step 6	DNA ligase forms a bond between the newest DNA and the DNA of fragment 1	21
1036383658	Synthesis of lagging strand Step 7	Laggin strand in this region is now complete	22
1036383659	Mismatch repair	Celluar process that uses specific enzymes to remove and replace incorrectly paired nucleotides	23
1036383660	Nuclease	cuts damanged DNA strand at two points so damaged section can be removed	24
1036383661	Enzymes involved with filling pre-damaged gap	DNA polymerase and DNA ligase	25
1036383662	Telomeres	Tandemly repetitive DNA at the end of a eukaryotic chromosome's DNA molecule. Telomeres protect the organism genes from being eroded during successive rounds of replication.	26
1036383663	Histones	Proteins that are responsible for the first level of DNA packing in chromatin	27
1036383664	Nucleosome	Basic unit of DNA packing. Consists of DNA wound twice around a protein core composed of two molecules each of the four main histone types	28
1036383665	Chromatin	Complex of DNA and proteins hat makes up eukaryotic chromosomes. When the cell is not dividing, chromatin exists in its dispersed form, as a mass of very long, thin fibers	29
1036383666	DNA replication	the process of making a copy of DNA	30
1036383667	transformation	the transfer of genetic material in the form of DNA fragments from one cell to another or from one organism to another	31
1036383668	bacteriophage	a virus that infects bacteria	32
1036383669	virus	ultramicroscopic infectious agent that replicates itself only within cells of living hosts	33
1036383670	double helix	two strands of nucleotides wound about each other; structure of DNA	34
1036383671	antiparallel	The opposite arrangement of the sugar-phosphate backbones in a DNA double helix.	35
1036383672	semiconservative	method of replication that implies that each new strand of DNA is half original and half new	36
1036383673	origin of replication	Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.	37
1036383674	helicase	an enzyme that untwists the double helix at the replication forks, separating the two parental strands and making them available as template strands	38
1036383675	single strand binding proteins	Proteins that bind to and stabilize the signle strands of DNA exposed when helicase unwinds the double helix in preparation for replication.	39
1036383676	topoisomerase	A protein that functions in DNA replication, helping to relieve strain in the double helix ahead of the replication fork.	40
1036383677	primer	An already existing RNA chain bound to template DNA to which DNA nucleotides are added during DNA synthesis., a short segment of DNA that serves as the starting point for DNA synthesis	41
1036383678	DNA polymerase	enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule	42
1036383679	DNA ligase	an enzyme that eventually joins the sugar-phosphate backbones of the Okazaki fragments	43
1036383680	nucleotide excision repair	The process of removing and then correctly replacing a damaged segment of DNA using the undamaged strand as a guide.	44
1036383681	telomerase	An enzyme that catalyzes the lengthening of telomeres. The enzyme includes a molecule of RNA that serves as a template for new telomere segments.	45
1036383682	nucleoid	A dense region of DNA in a prokaryotic cell.	46
1036383683	30nm fiber	nucleosomes associate with each other to form a more compact structure - results from interactions between adjacent histone H1 proteins	47
1036383684	looped domains	30-nm fiber forms loops that attach to a protein chromosome scaffold, making up a 300-nm fiber	48
1036383685	heterochromatin	Nontranscribed eukaryotic chromatin that is so highly compacted that it is visible with a light microscope during interphase	49
1036383686	euchromatin	a region of DNA that is uncoiled and undergoing active transcription into RNA	50
1036383687	gene expression	the process by which DNA directs the synthesis of proteins (or, in some cases, just RNAs)	51
1036383688	transcription	synthesis of an RNA molecule from a DNA template	52
1036383689	primary transcript	the initial RNA transcript from any gene, including those specifying RNA that is not translated into protein	53
1036383690	mRNA	messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome	54
1036383691	translation	The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule	55
1036383692	ribosomes	The sites of translation, complex particles that facilitate the orderly linking of amino acids into polypeptide chains.	56
1036383693	triplet code	3 bases of DNA that code for a single amino acid	57
1036383694	codons	mRNA base triplets	58
1036383695	template strand	The DNA strand that provides the template for ordering the sequence of nucleotides in an RNA transcript.	59
1036383696	reading frame	the way a cell's mRNA-translating machinery groups the mRNA nucleotides into codons	60
1036383697	RNA polymerase	pries the two strands of DNA apart and joins together RNA nucleotides complementary to the DNA template strand, thus elongating the RNA polynucleotide	61
1036383698	promoter	The DNA sequence where RNA polymerase attaches and initiates transcription	62
1036383699	terminator	In prokaryotes, a special sequence of nucleotides in DNA that marks the end of a gene. It signals RNA polymerase to release the newly made RNA molecule, which then departs from the gene.	63
1036383700	transcription unit	the stretch of DNA that is transcribed into an RNA molecule	64
1036383701	start point	nucleotide where RNA synthesis actually begins	65
1036383702	transcription factors	in eukaryotes, a collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription	66
1036383703	transcription initiation complex	the whole complex of transcription factors and RNA polymerase II bound to the promoter	67
1036383704	TATA box	A promoter DNA sequence crucial in forming the transcription initiation complex., a DNA sequence in eukaryotic promoters crucial in forming the transcription initiation complex (the transcription factors recognize this); "tells RNA pol where to land"	68
1036383705	5' cap	a methylated guanine nucleotide added to the 5' end of eukaryotic mRNA	69
1036383706	poly-A tail	The modified end of the 3' end of an mRNA molecule consisting of the addition of some 50 to 250 adenine nucleotides.	70
1036383707	RNA splicing	process by which the introns are removed from RNA transcripts and the remaining exons are joined together	71
1036383708	introns	a non-coding, intervening sequence within a eukaryotic gene	72
1036383709	exons	expressed sequence of DNA; codes for a protein	73
1036383710	spliceosome	A complex assembly that interacts with the ends of an RNA intron in splicing RNA, releasing the intron and joining the two adjacent exons.	74
1036383711	ribozymes	An enzymatic RNA molecule that catalyzes reactions during RNA splicing.	75
1036383712	domains	modular architecture on proteins consisting of discrete structural and functional regions	76
1036383713	alternative RNA splicing	A type of eukaryotic gene regulation at the RNA-processing level in which different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exons and which as introns	77
1036383714	aminoacyl-tRNA synthetases	an enzyme that joins each amino acid to the appropriate tRNA	78
1036383715	tRNA	short-chain RNA molecules present in the cell (in at least 20 varieties, each variety capable of combining with a specific amino acid) that attach the correct amino acid to the protein chain that is being synthesized at the ribosome of the cell (according	79
1036383716	anticodon	group of three bases on a tRNA molecule that are complementary to an mRNA codon	80
1036383717	wobble	flexibility in the base-pairing rules in which the nucleotide at the 5' end of a tRNA anticodon can form hydrogen bonds with more than one kind of base in the third position (3' end) of a codon	81
1036383718	rRNA	The most abundant type of RNA, which together with proteins froms the structure of ribosomes. Ribosomes coordinate the sequential coupling of tRNA molecules to mRNA codons	82
1036383719	P site	holds the tRNA carrying the growing polypeptide chain.	83
1036383720	A site	holds the tRNA carrying the next amino acid to be added to the chain	84
1036383721	E site	This site is the place where discharged tRNAs leave the ribosome.	85
1036383722	polyribosomes	An aggregation of several ribosomes attached to one messenger RNA molecule.	86
1036383723	signal recognition particle	binds to the signal sequence and the ribosomal subunits and transports the complex to the ER	87
1036383724	signal peptide	A stretch of amino acids on a polypeptide that targets the protein to a specific destination in a eukaryotic cell.	88
1036383725	nucleotide-pair substitution	A type of point mutation in which one nucleotide in a DNA strand and its partner in the complementary strand are replaced by another pair of nucleotides.	89
1036383726	mutation	change in a DNA sequence that affects genetic information	90
1036383727	silent mutation	A mutation that changes a single nucleotide, but does not change the amino acid created.	91
1036383728	nonsense mutation	A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein.	92
1036383729	missense mutation	The most common type of mutation, a base-pair substitution in which the new codon makes sense in that it still codes for an amino acid.	93
1036383730	point mutation	mutation that affects a single nucleotide, usually by substituting one nucleotide for another	94
1036383731	insertion	A mutation involving the addition of one or more nucleotide pairs to a gene.	95
1036383732	deletion	The loss of one or more nucleotides from a gene by mutation; the loss of a fragment of a chromosome	96
1036383733	frameshift mutation	mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide	97
1036383734	mutagen	any agent (physical or environmental) that can induce a genetic mutation or can increase the rate of mutation	98