| A | B |
|---|
| Chromatin Remodeling | can have heterochromatin or euchromatin |
| Heterochromatin | highly condensed, coiled with many solenoids |
| Euchromatin | loose, with few if any solenoids |
| Methylation | DNA methyltransferase inactivates gene expression by methylating the recognition sequences of promoters and enhancers, thereby preventing transcription factors from binding. |
| Epigenetics | Heritable change in DNA expression that...? ( Liger) |
| Which is more transcriptionally active? Euchromatin or Heterochromatin? | Euchromatin because RNA polymerase can reach the loose DNA of euchromatin |
| RNA Interference (RNAi) | inactivate expression of specific genes |
| micro RNAs (miRNA) | are short sequences that match part of the sequence of an mRNA. These miRNAs anneal to the complimentary region of the mRNA. |
| RNA induced silencing complex (RISC) | binds double stranded RNA and degrades the transcripts |
| RNA induced silencing complex (RISC) | "remembers" the mRNA and degrades any other transcripts with this sequence, whether or not they are bound by miRNAs. |
| DNA methyltransferase | inactivates gene expression by methylating the recognition sequences of promoters and enhancers |
| methylation | foundation of epigenetics |
| Histone Acyl Transferase (HAT) | induces euchromatin formation by acetylating the lysine residues of histones. This neutralizes the positive charge of the lysines, which prevent them from forming ionic bonds with the negative phosphates of DNA’s phosphodiester backbone. This prevents histones from binding DNA as strongly |
| Human Deacetylase (HDAC) | It removes acetyl groups from histone lysines, to induce heterochromatin formation and inhibit transcription. |
| RNAi | Researchers utilize ____ to knock out expression of specific genes. |
| antisense mechanism | . In this case double stranded RNA forms. Instead of being degraded as with RNAi, the ribosomes stalls when it reaches the double stranded region. |
