front 1 what is the genome? | back 1 a set of genetic information found in a nucleated eukaryotic somatic cell |
front 2 what does DNA consist of? | back 2 nucleotides arranged into genes and chromosomes |
front 3 DNA is | back 3 the structural blueprint for all genetic instructions |
front 4 purines (heterocyclic compounds) are- | back 4 adenine (A) and guanine (G) |
front 5 pyrimidines are- | back 5 cytosine (C) and thymidine (T) |
front 6 the backbone of DNA is made of- | back 6 a phosphate group bound to pentose by a phosphodiester bond (phosphate-deoxyribose backbone) |
front 7 the genetic code in the DNA is composed of how many bases | back 7 four |
front 8 The phosphodiester bond and one of the four bases bind by a ____________________ to form nucleotides | back 8 a strong covalent bond |
front 9 nucleotides bind to other nucleotides on the other DNA strand by ____________________ | back 9 weak hydrogen bond |
front 10 pentose molecules of the DNA backbone are asymmetrically joined to phosphate groups by | back 10 phosphodiester bonds |
front 11 _________________ between complementary __________________ interact to stabilize and form the double helix structure. | back 11 hydrogen bonds;nucleotides |
front 12 a DNA molecule is composed of | back 12 two antiparallel DNA strands held together by hydrogen bonds between the paired bases |
front 13 A and T form ____ hydrgen bonds | back 13 2 |
front 14 G and C form ____ hydrogen bonds | back 14 3 |
front 15 bases can only pair if the two polynucleotide chains that contain them are __________________________ | back 15 antiparallel to each other |
front 16 a single strand of DNA consists of | back 16 nucleotides joined together by sugar-phosphate linkages |
front 17 the asymmetry of the sugar-phosphate units give the backbone strand a definite- | back 17 directionality/polarity |
front 18 DNA exists as a- | back 18 double helix with about ten nucleotide pairs per helical turn |
front 19 the sugar in DNA is | back 19 deoxyribose |
front 20 phosphodiester bonds are bonds that- | back 20 form between the 3'-OH groups of the deoxyribose sugar on one nucleotide with the 5' phosphate groups on the adjacent nucleotide |
front 21 the 5' phosphate group of one nucleotide is bound to | back 21 the 3' hydroxyl group of the next nucleotide |
front 22 the _____ end of one strand is base-paired with the ____ end of the other strand. | back 22 5' ; 3' |
front 23 why do the bases in DNA have hydrogen bonds? | back 23 the hydrogen bonds between the bases can be made and broken easily, allowing DNA to undergo accurate replication and repair |
front 24 what is a nucleoside? | back 24 made up of a five-carbon sugar (pentose) bonded to a nitrogenous base and are formed by covalently linking the base to C-1' of the sugar |
front 25 what is a nucleotide? | back 25 they are formed when one or more phosphate groups are attached to C-5' of a nucleoside. |
front 26 what is the Watson-Crick model? | back 26 the double-helix structure of DNA |
front 27 what is Chargaff's rule? | back 27 amount of A = the amount of T, the amount of G = to the amount of C. Total purines = to Total pyrimidines overall |
front 28 what is denaturation? | back 28 separating/ breaking down DNA into two single strands |
front 29 what is reannealing? | back 29 when two complementary strands are put back together |
front 30 define chromatin | back 30 consists of DNA bound to histone and non-histone proteins |
front 31 what are histones? | back 31 small basic proteins, a heterogeneous group of closely related arginine- and lysine-rich basic proteins, make up 1/4 of amino acid residues |
front 32 histones- | back 32 bind tightly to the negatively charged sugar-phosphate backbone of DNA |
front 33 functionally, histones- | back 33 provide for the compaction of chromatin |
front 34 a chromosome is about- | back 34 1/3 DNA and 2/3 protein by mass |
front 35 structure of a nucleosome: | back 35 8 histone protiens (2 of each: H2A, H2B, H3, and H4) w/ double stranded DNA wound around it |
front 36 function of a nucelosome? | back 36 packaging DNA, regulate gene expression/activity |
front 37 define nuclease: | back 37 an enzyme that breaks down DNA |
front 38 what is formed during the progressive compaction of chromatin | back 38 higher order structures |
front 39 each core histone has- | back 39 a structured domain and an unstructured amino-terminal "tail" of 35 to 40 amino acid residues |
front 40 enzyme modification by _________________, __________________, or ______________ modifies the histones net elcteric charge and shape | back 40 acetylation, methylation, phosphorylation (changes are physiologically reversible and help prepare chromatin for DNA replication and transcription) |
front 41 heterochromatin is | back 41 densely packed or compacted regions of chromatin, and genetically inactive (transcription is inhibited here because the DNA is packaged so tightly that it is inaccessible to the proteins responsible for RNA transcription) |
front 42 euchromatin is- | back 42 less densely compact chromatin regions in a transcriptionally active nucleus. commonly undergoing, preparing for, or just having completed transcription. |
front 43 euchromatin represents | back 43 uncoiled chromatin structures that allow RNA polymerases' and regulatory proteins' access to DNA |
front 44 Telomeres: | back 44 hexametric DNA repeats (TTAGGG) found at the ends of chromosomes to protect the chromosome from degradation |
front 45 Centromeres: | back 45 allow mitotic spindles to attach to the chromosome during cell activation |
front 46 in order for DNA in chromosomes to replicate- | back 46 a certain nucleotide sequence acts as a DNA replication origin (each chromosome contains many origins of replication) |
front 47 kinetochore is | back 47 a protein complex that attaches the centromere to the spindle |
front 48 a gene is | back 48 the complete sequence region necessary for generating a functional product |
front 49 Translation | back 49 RNA ---> protein |
front 50 Transcription | back 50 DNA ----->RNA |