Topic 2 Molecular Genetics Flashcards

14929908702	2 nm	diameter of the double helix	0
14929911222	nucleic region	where bacterial chromosome is located	1
14929912750	Negative supercoils	DNA is underwound	2
14929922096	positive supercoils	DNA is overwound	3
14929922701	topoisomerase	clips DNA to move the strands to relieve/generate supercoiling	4
14929926125	isomer	difference version of a molecule with slightly different structure	5
14929928529	generated	negative supercoiling is _____ by topoisomerase	6
14929929763	relieved	positive supercoiling is ___ by topoisomerase	7
14929930919	DNA gyrase	type II topoisomerase introduces negative supercoils to bacterial chromosome to begin compaction	8
14929961458	50; scaffold	Bacterial chromosome contains ____ huge loops attached to ____ proteins	9
14929968634	chromatin	DNA associated with specific proteins to compact the DNA	10
14929972513	compacted	gene expression can be controlled by having more or less ______ chromatin	11
14929976743	nucleosome	like a spool with DNA wrapped around it made up of histones	12
14929980471	Amino acid sturcture	amino - basic properties carboxyl - acidic R - unique for each type	13
14929986216	Nonpolar amino acids	Glycine, Alanine, Valine, Leucine, Isoleucine, Methionine, Proline	14
14929989771	Nonpolar aromatic amino acids	phenylalanine, tyrosine, tryptophan	15
14929992788	Polar uncharged amino acids	serine, threonine, cysteine, asparagine, glutamine	16
14929994881	polar negatively charged amino acids	aspartic acid, glutamic acid	17
14929996196	polar positively charged amino acids	lysine, arginine, histidine	18
14929998435	2	how may amino acids are negatively charged?	19
14929999353	3	How many amino acids are positively charged?	20
14930002942	peptides	amino acids linked together by peptide bonds	21
14930005083	peptide bond	link between the carboxyl and amino group has resonance (can rotate) bond by dehydration reaction forms a zig-zag chain trans orientation more often	22
14930012812	trans (based on the alpha carbon)	What orientation are the peptide bonds more likely to be form in?	23
14930018389	primary structure	string of amino acids sequence peptide bonds maintain this structure	24
14930019453	secondary structure	alpha helix or beta sheets hydrogen bonds within the backbone maintain this structure	25
14930023738	tertiary structure	final shape of the monomer based on all interactions disulfide bonding ionic interactions, hydrogen bonding, and covalent between R groups hydrophobic exclusion (moves inside) overall 3D structure of a folded polypeptide chain	26
14930029525	quaternary structure	multiple peptide chains together	27
14930041478	alpha helix	10 to 15 amino acids long hydrogen bonds between the backbone N-H - - - O=C right handed 3.6 residues per turn 1.2 nm diameter	28
14930063454	no consecutive bulky/long R groups no consecutive like charged r groups few with polar R groups (Ser, Thr, Asn, and Asp) rarely have glycine and proline (found in turns)	What sequence can form an alpha helix?	29
14930073897	resonance	Proline destroys the ____ in the peptide bond because of the ring structure attaching to the carboxyl group	30
14930081046	antiparallel	beat sheets can be parallel or antiparallel but ____ are stronger because the hydrogen bonds between the sheets are aligned better	31
14930087587	elastic	alpha helixes have ____ properties which is why hair can be stretched and not break, but it will break if stretched too far	32
14930093751	strength	beta sheets give _____ to the substance such as silk which has lots of beta sheets	33
14930094775	super secondary structure	elements of secondary structure coming together that creates a unique property	34
14930098724	Helix-turn-helix	A protein domain composed of two α helices joined by a short strand of amino acids and is found in many DNA binding proteins. can fit into the major groove to act at the binding site of a protein	35
14930103189	four-helix bundle	super secondary structure	36
14930106635	coiled-coil	stable, rodlike protein structure formed when two or more alpha helices twist around each other	37
14930112458	Beta hairpin	antiparallel strands connected by relatively tight reverse turns super secondary structure	38
14930115786	antiparallel beta sheets	align in opposite directions	39
14930117536	beta barrel	created when beta sheets are extensive enough to fold back on themselves forms a hole for things to pass through within the protein antiparallel	40
14930120677	Greek Key	a repetitive supersecondary structure formed when an antiparallel sheet doubles back on itself	41
14930124927	Beta-alpha-beta		42
14930129325	alpha/beta barrel	a beta barrel in which successive parallel beta strands are connected by alpha helices such that a barrel of alpha helices surrounds the beta barrel forms a hole	43
14930139612	hydrophobic exclusion	The tendency of nonpolar molecules to aggregate together when placed in water. Exclusion refers to the action of water in forcing these molecules together. move inside of the protein to avoid water	44
14930142030	oligomers	proteins composed of several peptides multiple subunits	45
14930144194	homooligomer	oligomer with identical subunits	46
14930145184	heterooligomer	nonidentical subunits	47
14930148118	prion	infectious agent - simply misfolded protein if it gets to the brain, aggregate together, causes the normal version to change into this version, causes neuron death	48
14930159315	dynamic	chromatin structure is ___ meaning that it can control the flow of information by changing the structure	49
14930162482	beads on a string	histone core of the nucleosome with DNA wrapped around it, about 11 nm in width	50
14930173734	200	when chromatin is cut with a nonspecific nuclease, the fragments differ in length by about _____ bp meaning that the nucleosomes must be spaced out about ____ bp	51
14930176147	histones	A small protein with a high proportion of positively charged amino acids that binds to the negatively charged DNA and plays a key role in chromatin structure. 20% made of lysine and arginine	52
14930180330	N	the __-terminal tails are important for the regulation of chromatin structure	53
14981373084	dimers	H2A and H2B form two _____	54
14981379116	tetramer	H3-H4 form a ____	55
14981387345	N-tails	stick out from the histones to wrap around the DNA	56
14981401777	Histone Octomer	Made up of 2 of each type of histone; H2A, H2B, H3, and H4	57
14981410660	1.67; 146	The DNA wraps around the histone octomer ____ and is ____ base pairs in length (left handed supercoil)	58
14981473830	Histone acetyltransferase (HAT)	acetylates lys in the histone tails; loosens the tail from the DNA to open up the DNA for replication or transcription	59
14981493726	Histone Deacetylase (HDAC)	removes acetyl groups from the histone tails closing the tails back down not he DNA closing it off to replication and transcription	60
14981511163	Phosphorylation	adds a negative charge so it will repel DNA (loosen up DNA)	61
14981526549	Linker histone	H1 - packs the nucleosomes closer together (lots of positively charged amino acids to be attracted to DNA)	62
14981565389	30 nm fiber	interactions between nucleosomes cause the thin fiber to coil or fold into this thicker fiber coil of the beads on the string (6 nucleosomes per turn)	63
14981574029	2 nm fiber	naked DNA	64
14981580727	11 nm fiber	nucleosomes	65
14986747115	Euchromatin	undergoes condensation and decondensation during cell cycle - may become transcriptionally active Less compacted	66
14986764942	heterochromatin	stays more condensed, not as active or accessible for proteins more compacted (chromatin structure)	67
14986783150	300 nm	30 nm fibers looped and attached to scaffold proteins	68
14986794440	700 nm fiber	coiling of the 300 nm fibers attached to the scaffold proteins	69
14986831341	50,000; 1,400	the mitotic chromosome is about ____ times shorter than the naked DNA and known as the ____ nm fiber	70
14986850878	nucleoli	sites in the nucleus where ribosomal RNA genes are made by RNA polymerase; ribosomal subunits assembled in that region	71
14986886196	Chromosome territories	regions of the nucleus preferentially occupied by particular chromosomes seen during interphase (not condensed DNA)	72
14986901811	FISH	Staining technique called Fluorescent in situ hybridization chromosome specific sequences that will hybridize to only certain chromosomes with a specific fluorescent tag to label	73
14986955033	Chromosome map	based on the FISH images where chromosomes are located during interphase the organization can show the complications that arise for repair and cross over possibilities based on location within the nucleus	74