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level: Level 1

Questions and Answers List

level questions: Level 1

Question	Answer
1. DNA loops twice around histone octamer 2. Nucleosome is the histone octamer complex with DNA loops	Characteristics of chromatin structure. What is a nucleosome
Condensed, transcriptionally inactive. high methylation, low acetylation Ej: Barr bodies (inactive X Chromosome)	Characteristics of Heterochromatin
Less condensed, transcriptionally active. --> Euchromatin is Expressed	Euchromatin Characteristics
Represses transcription in DNA --> Methylation makes DNA mute In template strand distingue entre old y new	DNA methylation
Reversibly represses DNA transcription, but can activate it. --> Mostly makes DNA mute	Histone methylation
Relaxes DNA coiling allowing for transcription --> Acetylation makes DNA Active	Histone acetylation
Base + deoxyribose (Sugar)	Que es un NucleoSide?
Base + Deoxyribose + phosphaTe	Que es un NucleoTide?
PURE As Gold --> Adenina y Guanina	Cuáles son las PURINAS?
CUT the PY --> Citosina, uracilo, timina	Cuáles son las PIRIMIDINAS?
Adenina con timina (2 H bonds) y Guanina con citocina (3 H bonds) Crazy Glue	Cómo son las uniones entre las bases nitrogenadas?
1. deaminación 2. deaminación 3. metilación	1. Cómo se sintetiza guanina de adenosina? 2. Cómo se sintetiza uracilo de citocina? 3. Cómo se sintetiza timina de uracilo?
Leflunamide: dihidroorotato deshidrogenasa MTX, TMP, Pyrimethamine: Dihidrofolato reductasa 5-FU: Thymidylate synthase 6-MP: producción de novo de purinas Mycophenolato: inosine monophosphate dehidrogenase Hydoxyurea: ribonucleotide reductase	Qué inhibe Leflunomide, metrotexate, TMP, pyrimethamine, 5-FU, 6-MP, Mycophenolato, hydroxyurea?
Necesaria para degradación de adenosina y deoxiadenosina por lo que aumenta dATP --> tóxico para linfocitos --> Causa SCID	Características de deficiencia de adenosina deaminasa y que hace esta encima?
1. Hipoxantina-Guanina Fosforibosil transferasa (HGPRT) 2. Converts hipoxantina to IMP and guanina GMP. Hay exceso de acido urico y producción de purinas de novo. 3. Hyperuricemia, Gout (orange sand in diaper), Pissed off (aggression, self mutilation), Retardation, disTonia 4. X linked	Características de Lesch-Nyhan syndrome. 1. Enzima deficiente 2. Función 3. Características clínicas 4. Genética
Specific base pairing is usually only required in the first 2 nucleotide position	Cual es la Wobble Hypothesis?
Methionine and tryptophan	Aminoácidos que solo se codifican poor un codon?
Glycine, Aspartate, Glutamine--> GAG	Amino acids necessary for purine synthesis:
Y shaped region along DNA template	Replication Fork
Unwinds DNA template	Helicase
Break in the helix to add or remove supercoils. Irinotecan: topoisomerasa I Etoposide: Topoisomerasa II Fluoroquinolones: prokaryotic topoisomerase II and IV	DNA topoisomerases and inhibitors
Makes an RNA primer para que polymerase III initiate replication	Primase
Elongates leading strand	DNA polymerase III
Degrades RNA primer and replaces with DNA	DNA polymerase I
Joins Okazaki fragments	DNA ligase
Adds DNA to 3' to avoid loss of genetic material	Telomerase
1.Purine to purine or pyrimidine to pyrimidine 2. purine to pyrimidine	Mutations in DNA 1.Transition 2.Transversion
El cambio de nucleotido codifica para la misma proteína	Silent Mutation
Resulting in changed aminoacid. Sickle cell anemia ( glutamic acid --> valine) Nonsense: codifica para un STOP	Missense mutation and example Nonsense
Deletion or insertion of a number of nucleotides not divisible by 3. Causes misreading Duchenne, Tay-Sachs	Frameshift mutation and example
Mutation at a splice site	Splice site
Example of a genetic response to an environmental change En E.coli cuando hay cambio de sustrato de alta glucosa a alta lactosa.	Lac operon