Topic 8: Control of Gene Expression
Genes present in all cells that perform important cellular functions like DNA replication/repair and protein production; frequently used as a control in molecular biology experiments.
What are housekeeping genes?
This occurs when one inherited parental gene copy is active and the other is silent
What is genomic imprinting?
The major lipids in cell membranes.
What are glycerophospholipids, sphingolipids, and sterols?
Channels and transporters are the two main classes of this.
What are membrane transport proteins?
This long non-coding RNA, located on the X chromosome, is synthesized which initiates the inactivation process of the X-chromosome
What is Xist?
Transcriptional regulators bind to these are short sequences that can be located upstream (near or far) to the transcription start site.
What are cis-regulatory sequences (or regions)?
This process occurs in mammals with two X-chromosomes where one X chromosome is inactivated
What is X-inactivation?
A class of molecules which act to stiffen the lipid bilayer, making it less deformable. Within the lipid bilayer, their hydroxyl groups associated with the polar heads of phospholipids and their rigid steroid rings stiffening the hydrocarbon tails.
What are Sterols?
These constitute the three classes of ATP-driven pumps.
What are P-type pumps (phosphorylate themselves during the pumping cycle), ABC transporters (ATP-Binding Cassette, primarily pump small organic molecules), and V-Type pumps (turbine like protein machines constructed from multiple different subunits)?
When bacteria or archaea have been infected by a virus, small fragments of viral DNA incorporate into the bacterial or archaeal genome. These small fragments are treated as templates for creating small non-coding RNAs known as ___ that will destroy the virus if it tries to reinfect the descendants of the parental cell
What are crRNAs (CRISPR RNAs)?
This term describes the area in eukaryotes containing all the elements needed to guide transcription such as the cis-regulatory sequences, the corresponding promoter, and any intervening DNA sequences.
What is a gene control region?
This enzyme is involved in an RNAi pathway where it cleaves a double-stranded RNA into small fragments called siRNAs
What is Dicer?
Adipocytes contain this which fills up most of its cytoplasm, which the cell can later utilize for membrane construction or for metabolism.
What is a lipid droplet?
Transport distributed nonuniformly between, say, the basolateral and apical layers of epithelial cells in the gut is known as this.
What is transcellular transport?
This P-type pump is found in the sarcoplasmic reticulum of skeletal muscle and involved in muscle contractions.
What is Ca2+ pump or Ca2+ ATPase?
Unlike most DNA modifications, this modification mechanism makes it difficult to reactivate genes and results in the creation of heterochromatin.
What is methylation?
These are found near the 5’ end of mRNAs, they can allow or block the progress of RNA polymerase depending on if there is a specific small molecule bound such as a metabolite
What is a riboswitch?
The covalent linkage of oligosaccharides to the lipids and proteins on a cells surface which protect the cell from mechanical and chemical damage.
What is glycosylation?
This ABC transporter, or P-glycoprotein, was discovered because of its ability to pump hydrophobic drugs out of the cytosol and is often found in elevated levels in many human cancer cells.
What is multidrug resistance protein?
The number of sequentially activated sets of ion channels causing a muscle to contract.
What is five?
Transcription factors can recognize these two characteristic features of the major and minor groove to find a regulatory sequence rather than directly accessing the DNA sequence.
What is hydrogen bonding and hydrophobic interactions?
In A-to-I editing, this enzyme recognizes the double-stranded RNA and edits adenosine to inosine
What is ADAR (adenosine deaminases action on RNA)?
This transmembrane protein motif is always arranged as a cylinder.
What is Beta-barrel membrane proteins?
In nerve cells, the action potential stimulates these to release a specific ion, depolarizing the cell.
What is the voltage gated Na+ channels?
Transcription regulators that can bind to DNA on nucleosomes with similar affinity as they would on naked DNA are often called this
What are pioneer factors?