Heterochromatin Study guides, Class notes & Summaries

A - Alanine (1 letter) Activation of enzymes through ligand binding: why would this be useful? - The binding of a ligand to an allosteric site of a multimeric enzyme often induces positive cooperativity, that is the binding of one substrate induces a favorable conformation change and increases the enzyme's likelihood to bind to a second substrate. Ala - Alanine (3 letter) Arg - Arginine (3 letter) Asn - Asparagine (3 letter) Asp - Aspartic Acid (3 letter) Barr body and relation to heter...

USMLE STEP 1 BIOCHEMISTRY Questions and Answers with Complete Solutions 2024 histones are rich in which 2 AA's - ANSlysine & argenine Barr bodies (what, type of chromatin) - ANSinactive X chromosomes heterochromatin (highly condensed, sterically inaccessible) less condensed, transcriptionally active, sterically accessible chromatin - ANSeuchromatin DNA methylation at CpG islands - ANSrepresses transcription "CpG Methylation makes DNA Mute" DNA methylation (what is methylated and why?) ...

Cell division is used for which of the following ? Reproduction of single-celled organisms, growth of multicellular organisms, repair and replacement of cells, and sperm and egg production Asexual and sexual reproduction differs in that sexual reproduction_____________ Can produce great variation among the offspring (Meiosis) Asexual Reproduction ____________ Produces offspring genetically identical to the parent (Mitosis) Most of the time, DNA is in the form of____________ Euchromatin W...

histones are rich in which 2 AA's (Ans- lysine & argenine Barr bodies (what, type of chromatin) (Ans- inactive X chromosomes heterochromatin (highly condensed, sterically inaccessible) less condensed, transcriptionally active, sterically accessible chromatin (Ans- euchromatin DNA methylation at CpG islands (Ans- represses transcription "CpG Methylation makes DNA Mute" DNA methylation (what is methylated and why?) (Ans- template strand cytosine and adenine are methylate...

BIOL 2300 Quizzes 1-7 Latest Update Graded A+ DNA is negatively charged because a. the ribose sugars of DNA are positively charged b. the ribose sugars of DNA are negatively charged c. the nitrogenous bases are negatively charged d. the phosphate backbone of DNA is negatively charged e. DNA is not acidic d. the phosphate backbone of DNA is negatively charged DNA replication is a. semi-conservative b. dispersive c. conservative d. error prone a. semi-conservative Define D...

Describe how H3Lys9me heterochromatin is formed ~~> H3Lys9me heterochromatin formation: Lys9 deacetylated by HDAC. Suvar39 then methylates lys9. Methylated lys9 is recognised by HP1 and then HP1 binds. HP1 has chromodomain - chromodomains often recognise and bind to methylated lys residues. Chromodomain on HP1 is specific for H3Lys9me (with di or tri methylated lys 9). Binding of HP1 is thought to compact nucleosome arrays as HP1s join together. What is gene expression? ~~> ...

USABO Exam Questions and Answers 100% VerifiedUSABO Exam Questions and Answers 100% VerifiedUSABO Exam Questions and Answers 100% VerifiedUSABO Exam Questions and Answers 100% Verified Eukaryote - ANSWER - An organism whose cells contain complex structures enclosed within membranes. The defining membrane bound structure thats sets them apart from prokaryotic cells is the nucleas or nuclear envelope within which the genetic material is carried. All species of large complex species are eukaryotes...

Histones are rich in what AAs? - ANSWER ☑☑Lysine and arginine (both + charge) When does histone synthesis occur? - ANSWER ☑☑S phase (along with DNA getting synthesized) Heterochromatin is _________, euchromatin is _________ - ANSWER ☑☑Inactive/condensed; active/accessible What allows mismatch repair enzymes to distinguish between old and new DNA strands in prokaryotes? - ANSWER ☑☑Methylation; old/template strands are methylated, new/daughter strands are unmethylated ...

DNA is negatively charged because a. the ribose sugars of DNA are positively charged b. the ribose sugars of DNA are negatively charged c. the nitrogenous bases are negatively charged d. the phosphate backbone of DNA is negatively charged e. DNA is not acidic : d. the phosphate backbone of DNA is negatively charged DNA replication is a. semi-conservative b. dispersive c. conservative d. error prone : a. semi-conservative Define DNA helicase : unwinds DNA; that is, breaks the hydrog...

Pyrimidine dimers formed in DNA due to UV radiation can be repaired by? SOS repair Double strand break repair Mismatch repair Photoreactivation repair (nucleotide excision repair) Base excision repair - CORRECT ANSWER Photoreactivation repair (nucleotide excision repair) Which of the following repair mechanisms uses methyl groups to distinguish between parental and daughter strands? Answers: Mismatch repair Photoreactivation repair (Nucleotide excision repair) SOS repair Doub...