BB Flashcards
(5 cards)
What is cadherin?
Cadherins are transmembrane proteins which play a primary role in cell-to-cell adhesion (remember that C stands for cell-to-cell), forming adherens junctions to bind cells within tissues together.
What is integrin?
Integrins are transmembrane receptors that modulate cell-to-extracellular matrix interactions. Specifically, these proteins often attach the cell to collagen and fibronectin fibers.
What is commensalism?
When one species benefits but the other species is neither helped nor harmed, that is commensalism.
TCA
Content Foundations: Citric Acid Cycle
The citric acid cycle, also known as the Krebs cycle, is a major step in aerobic metabolism. It is the next step of glucose metabolism after glycolysis, but it is also the crossroads of various metabolic pathways in the body (that is, non-carbohydrate precursors can be fed into it, and its intermediates can be siphoned off to use as building blocks for other classes of molecules). The citric acid cycle does generate some ATP directly (through GTP), but its main value is that it generates several electron-carrying molecules that are fed into the electron transport chain to generate much larger amounts of ATP.
In eukaryotes, the citric acid cycle takes place in the mitochondrial matrix, while in aerobic prokaryotes it is carried out in the cytosol. Before entering the citric cycle, pyruvate (a three-carbon molecule) must be converted into acetyl-CoA, a molecule that consists of a short two-carbon chain (the “acetyl” group) connected to CoA. This takes place in the mitochondria, in a special area called the pyruvate dehydrogenase complex (PDC), and results in 1 NADH and 1 CO2.
The basic logic of the citric acid cycle is that the two-carbon molecule acetyl-CoA joins with the four-carbon molecule oxaloacetate to form a six-carbon molecule known as citrate. Citrate then undergoes a series of redox and decarboxylation reactions to generate the products of the citric acid cycle. The final product is the four-carbon compound oxaloacetate, which joins with acetyl-CoA to start the process again. Each turn of the citric acid cycle generates 1 GTP (which you can think of as functionally equivalent to ATP), 3 NADH, 1 FADH2, and 2 CO2. NADH and FADH2 are electron transporters that ultimately produce energy through the electron transport chain.
Even though oxygen is not a reactant or a product, the citric acid cycle requires oxygen indirectly, because it is dependent on the aerobic electron transport chain to regenerate NAD+ and FAD for the process to continue.
5’UTR region
stands for untranslated region
IS ALWAYS TRANSCRIBED, but not always translated
