Topic 8
Production of enzymes needed to break down lactose into usable sugars when lactose is available as a food source.
What is the function of the lac operon?
To bind to small non-coding RNAs like microRNAs (miRNAs) and small interfering RNAs (siRNAs) to silence gene expression by either cleaving target messenger RNAs (mRNAs) or inhibiting their translation into proteins.
What is the function of argonaute?
The most abundant membrane lipid.
What are phospholipids?
The use energy from ATP hydrolysis by P-type ATPases to transport ions across the membrane against a concentration gradient.
What is active ion transport?
The most important point of gene expression control.
What is transcriptional regulation?
Each cell contains a specific set of these proteins to ensure that correct expression within the cell type occurs.
What are transcription regulator proteins?
They extend across the bilayer in different ways; an example could be a single-pass protein crossing the bilayer as a single alpha helix, while a polypeptide chain of multi-pass protein crosses multiple times as a series of alpha helices or as a beta-sheet rolled into a barrel.
What are transmembrane proteins?
P-type pumps, ABC transporters, and V-type pumps.
What are the three main families of ATP-driven pumps?
Introns are removed from the pre-mRNA transcript, and different combinations of exons can be spliced together, leading to multiple proteins from a single gene
What is splicing during translation?
These cultured fibroblast cells undergo de-differentiation when specific transcription regulators are artificially expressed.
What are induced pluripotent stem cells (iPS cells)?
This term refers to dynamic microdomains in the lipid bilayer that concentrate specific lipids and proteins, playing a key role in signal transduction and membrane trafficking.
What are Lipid Rafts?
Also known as a vacuolar ATPase (V-ATPase), a protein complex found in the membranes of eukaryotic cells that actively transports protons (hydrogen ions) across the membrane.
What are V-type proton pumps?
They exist as a dimer, two alpha helices, each as a monomer, and together, they form a coiled coil. Dimerized via hydrophobic interactions on one side of each helix, in this dimerized form, grips DNA like a clothespin on a clothesline.
What is a leucine zipper?
These cytoplasmic structures store inactive mRNAs for future reactivation.
What are P-bodies?
This cytoskeletal protein forms a flexible mesh beneath the plasma membrane of red blood cells, maintaining their biconcave shape and structural integrity.
What is spectrin?
This type of transporter uses ATP hydrolysis to move substrates like drugs or lipids across membranes, often contributing to multidrug resistance in cancer cells.
What is ABC?
This specific histone modification marks heterochromatin for repression.
What is H3K9me3?
These transcription regulators are able to bind to DNA and cause the double helix to curve or “bend” at a sharp angle, affecting initiation of transcription indirectly.
What are bending proteins?
Movement that proteins undergo wherein they move laterally in the membrane bilayer and whose diffusion rate can be detected by fluorescence recovery after photobleaching (FRAP)?
What is lateral diffusion?
This equation can help determine the resting membrane potential of inorganic ion flow through a membrane channel.
What is the Nernst Equation?