Basic Biochem Flashcards
What are the types of chromatin?
Hetero and Euchromatin
How does euchromatin differ from heterchromatin on electronic microscopy?
Euchromatin is lighter
Heterochromatin is darker
Give an example of heterochromatin
Barr bodies (X chromosome muted in women)
What is the difference between heterochromatin and euchromatin sterically and transcriptionally?
Heterochromatin is sterically inaccessible and transcriptionally inactive aka MUTED
Euchromatin is sterically accessible and transcriptionally active aka EXPRESSED
Which type of chromatin has increased methylation?
Heterochromatin
Where does DNA methylation generally occur?
At promoter genes just ahead of where DNA is actually transcribed
What does CpG stand for?
Cytosine - phosphate - guanine
Role of promoter gene
Region that enzymes bind to to commence transcription
What is DNA methylation
Muting the expression of DNA without changing its sequence
Examples of DNA methylation
Aging
Carcinogenesis
Lyonization (one X chromosome in women muted)
Genomic imprinting (mother or father gene muted)
Condition where DNA methylation has gone awry
Fragile X syndrome
Where does DNA methylation specifically occur?
CpG islands
