Explanation:
The Exon Junction Complex (EJC) is a eukaryotic molecular machine that interacts with spliced mRNA upstream of exon-exon junctions, providing a binding platform for other trans-acting proteins that determine the fate of the mRNA. The spliceosome deposits the ~335kD EJC in a non-sequence specific manner 20-24 nucleotides upstream of an exon-junction. Functionally, the EJC aids in nuclear export of spliced mRNAs, assists in nonsense-mediated decay of incorrectly spliced mRNAs containing premature stop codons, and enhances translation efficiency.
Pre-mRNA bound by a spliceosome is usually not exported from the nucleus, so as to make sure that only fully-processed mRNA travels to the cytoplasm to be translated. A protein called the mRNP exporter binds to the EJC, both through RNA interactions and interactions with the EJC-associated protein REF (RNA export factor) to help pre-mRNA exit the nuclear pore complex.
Interestingly, the efficiency of unspliced mRNA export is dependent on the length; longer mRNAs are exported more efficiently than shorter mRNAs. In spliced mRNAs, however, once the 5' exon is long enough to bind the EJC, the length of the spliced mRNA does not affect the export efficiency.
There are a certain number of EJCs in a cell, and they must be recycled in order to continue tagging mature mRNAs. Once in the cytoplasm, the ribosome-associated regulator protein (PYM) acts as a dissociation factor.
The coriolis effect makes ocean currents move<span> in a curved path</span>
a. 2 > The 23rd pair, the sex chromosomes, differ between males and females (females have two copies of the X chromosome, while males have one X and one Y chromosome). In humans, the sex chromosomes comprise one pair of the total of 23 pairs of chromosomes. The other 22 pairs of chromosomes are called autosomes. <em>Chromosomes are thread-like molecules that carry hereditary information (they are made of protein and one molecule of DNA, which contains an organism's genetic instructions).</em>
1. Identify the energy transformations in the following actions. (10 points)
Turning on a space heater
Dropping an apple core into the garbage
Climbing up a rope ladder
Starting a car
Turning on a flashlight
Answer:
Scientist 1 because the rest of them probably learned from his mistakes.
Explanation:
