Membranes â¢ Provide barrier function â Extracellular â Organelles â¢ Barrier can be overcome by âtransport proteinsâ â To mediate transmembrane movements of ions, Na + , K + â Nutrients, glucose, amino acids etc. â Water (aquaporins).
Boron is a chemical element with symbol B and atomic number 5. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is a low-abundance element in the Solar system and in the Earth's crust.
Rating Newest Oldest. Best Answer: Boron 11 is one of two stable isotopes of Boron. and in natural samples about 80-81% of the element is Boron-11 and 19-20% is Boron-10. Boron-10 has 5 protons 5 neutrons and 5 electrons. Boron-11 has 5 protons 6 neutrons and 5 electrons.