Fuel cells can make an electricity from a simple electrochemical
reaction in which oxygen and hydrogen combine to form water. There are several
different types of fuel cell but they are all based around a central design
which consists of two electrodes, a negative anode and a positive cathode.
These are separated by a solid or liquid electrolyte that carries electrically
charged particles between the two electrodes. A catalyst, such as platinum, is
often used to speed up the reactions at the electrodes. Fuel cells are
classified according to the nature of the electrolyte. Every type needs
particular materials and fuels and is suitable for any applications. The
article below uses the proton exchange membrane fuel cell to illustrate the
science and technology behind the fuel cell concept but the characteristics and
applications of the other main designs are also discussed. Proton Exchange Membrane Fuel Cells (PEMFC)
The hydrogen ions permeate across the electrolyte to the
cathode, while the electrons flow through an external circuit and provide
power. Oxygen, in the form of air, is supplied to the cathode and this combines
with the electrons and the hydrogen ions to produce water. These reactions at
the electrodes are as follows:
Anode: 2H24H+ + 4e-
Cathode: O2 + 4H+ + 4e- 2H2O
Overall: 2H2 + O22H2O + energy
PEM cells operate at a temperature of around 80°C. At this
low temperature the electrochemical reactions would normally occur very slowly
so they are catalysed by a thin layer of platinum on each electrode.
Choice b choice b choice b choice b choice b
Answer: Both the mouse and human beings are encoding the proteins having similar functions.
Explanation:
The CFTR gene in the mouse and CFTR gene in the human beings encode proteins that perform similar function,this is so because if the results are same then it means that both mouse and human beings are encoding the protein that have similar function.
Option A is incorrect because both humans and mouse are eukaryotes so they have introns and because of that even if the gene sequences are different they can still encode protein.
Option B is incorrect because amino acid sequences can be similar inorder to have the similar function. If glutamic acid is replaced by aspartic acid, it won't have different function the function will remain same. So, identical amino acid sequences are not required. They can be similar too.
Solar panels allow us to harness photons or solar energy or thermal, and convert it to eletric energy.
Explains the heart and breathing rate
