Chapter 14 Biology Raven Flashcards

2734760671	Bacteriophages (phages)	viruses that affect bacteria	0
2734765974	Lyse (lytic phage)	cell burst	1
2734765975	DNA structure	1. A five carbon sugar (deoxyribose in DNA and ribose in RNA) 2. A phosphate group (PO4) 3. A nitrogenous base (either purine or pyrimidine)	2
2734765976	Purine	Adenine (A) or Guanine (G) 2 ringed structure	3
2734765977	Pyrimidine	Thymine (T) or Cytosine (C) or Uracil (U) Single ringed structure	4
2734769114	Chargoff's rule	A=T G=C	5
2734770041	Dehydration synthesis	The 5' phosphate and 3' hydroxyl groups allow DNA and RNA strands to form long chains of nucleotides	6
2734772082	Phosphodiester bonds	the phosphate group is now linked to the 2 sugars by a pair of ester bonds	7
2734781056	Tautomers	Keto (C=O) versus enol (C-OH) groups and amino (_NH2) versus imino (=NH) groups that are attached to the bases	8
2734781057	Phosphodiester backbone	repeating sugar and phosphate units joined by phophodiester bonds	9
2734781058	Base pair	two strands held together by formation of hydrogen bonds and between bases on opposite strands. Adenine can form two hydrogen bonds withthymine to form a A-T base pair Guanine can form three hydrogen bonds with cytosine to form a G_C base pair	10
2735970431	Antiparallel	one strand running 5'to3' and the other running 3'to5'	11
2735970432	Three possible models of DNA	conservative model semiconservative model dispersive model	12
2735970433	Semiconservative model	produces 2 hybrid molecules of old and new strands	13
2735972890	DNA replication	opening up one DNA helix and making copies of both strands to produce two daughter helices, each consisting of one old strand and one new strand	14
2735980828	DNA polymerase	add new bases to the 3' end of existing strands and requires a primer to begin synthesis. Refers to a group of enzymes responsible for the building of a new DNA strand from the template.	15
2735980829	RNA polymerase	synthesis their primers	16
2736197625	DNA Pol 1, 2, 3	all three enzymes synthesize polynucleotide strands only in the 5'-3' direction and require a primer	17
2736202360	Nuclease activity	ability to break phosphodiester bonds between nucleotides (endonucleases and exonucleases)	18
2736202361	Endonucleases	Cut DNA internally	19
2736203373	Exonucleases	Chew away at an end of DNA	20
2736220479	DNA Polymerase 1	Acts on lagging strand to remove primers and replace them with DNA	21
2736220480	DNA Polymerase 2	DNA repair process	22
2736220481	DNA Polymerase 3	Main replication enzyme. Synthesize okazaki fragments	23
2736340342	Helicases	Enzymes that use energy from ATP to unwind the DNA template	24
2736340343	Single-strand-binding protein (SSB)	Coats the exposed hydrophobic base of the single strand	25
2736340344	Supercoiling	The coiling in space of double-stranded DNA molecules due to torsional strain, occurs when the helix is unwound	26
2736340345	Topoisomerase	Enzymes that can alter the topological state of DNA	27
2736340346	DNA gyrase	The topoisomerase involved in DNA replication. Enzyme that relieves strain while helicase has unwound the strands	28
2736340347	Semidiscontinuous	One strand can be synthesized in a continuous fashion from an initial primer, while the other strand must be synthesized in a discontinuous fashion with multiple priming events and short sections of DNA being assembled	29
2736340348	Leading strand	Continuous	30
2736340349	Lagging strand	Discontinuous	31
2736340350	Okazaki fragments	Fragments synthesized on lagging strand	32
2736340351	Replication fork	Partial opening of DNA helix to form 2 single strands	33
2736340352	Leading strand synthesis	A single priming event is required then the strand can extend indefinitely by the action of DNA Pol 3	34
2736340353	Processivity	The ability of a polymerase to remain attached to the template	35
2736340354	Sliding clamp	Beta subunit in Pol 3 made up of 2 identical protein chains that form a circle around the strand	36
2736340355	Lagging strand synthesis	Primase is needed to synthesize primers for each okazaki fragment and then all these RNA primers need to be replaced with DNA. The fragments are stitched together.	37
2736361649	DNA ligase	Seals the gap, joining okazaki fragments into complete strands	38
2736361650	Termination	Last stage of replication produces two daughter molecules that are intertwined then unlinked by gyrase	39
2736361651	Replisome	Forms a macromolecular assembly Primosome and complex of 2 DNA Pol 3 enzymes	40
2736361652	Primosome	Composed of primate and helicase	41
2736361653	Eukaryotic replication	Has multiple origins of replication for each chromosome, resulting in multiple replicones	42
2736374826	Proliferating Cell Nuclear Antigen (PCNA)	Sliding clamp unit on eukaryotes	43
2736374827	Telomeres	Structure found on the end on eukaryotic chromosomes. They protect the ends from nucleases and maintain integrity of linear chromosome.	44
2736374828	Replicating ends	Lagging strands last primer is removed, it cannot be replaced. During the next round of replication the next chromosome will be shorter. Resulting in aging.	45
2736374829	Telomerase	Contains an internal RNA that the enzyme uses as a template to extend the DNA of the chromosome end. Cancer cells generally show activation of telomerase which allows them their length so they don't shorten.	46
2736374830	Mutagen	Agent that increases number of mutations (UV light, xrays, radiation)	47
2736374831	Specific repair systems	Target a single kind of lesion in DNA and only repair that lesion.	48
2736374832	Nonspecific repair systems	Use a single mechanisms to repair multiple kinds of lesions	49
2736381728	Photorepair	(Specific repair) specific for UV light damage (tymine dimer). Photolase absorbs light in the visible range and uses this energy to cleave the tymine dimer.	50
2736381729	Excision repair	(Nonspecific) recognizes damage, removes damaged region, resynthesizes using the info on the undamaged strand as a template	51
2736381730	UvrABC complex	Binds to damaged DNA and then cleaves a single strand on either side of the damage, removing it. DNA Pol 1 or 2 replaces damaged DNA	52