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.
Answer:
Gene pairs segregate randomly and independently of each other.
Explanation:
Genes are the basic units of hereditary and are located on chromosomes. According to Gregor Mendel's law of independent assortment which states that the alleles of two (or more) different genes are sorted into gametes independently of one another. This means that the allele a gamete receives for one gene does not influence the allele the same gamete receives for another gene.
For example, in a the pea plants used by Mendel in his studies, the genes for seed shape and flower color were inherited independent of each other by the offspring of the parent pea plants. Therefore, Mendel concluded that the inheritance of each trait was independent of the other.
Fat membrane metabolic disorder facts hamster cells were marked with a blue dye and membrane proteins
Answer:
i can only define the terms for you.
Explanation:
chromosome - a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
chromatid - each of the two threadlike strands into which a chromosome divides longitudinally during cell division, each containing a double helix of DNA.
gene - a distinct sequence of nucleotides that forms a part of a chromosome, the order of which determines the order of monomers in a polypeptide or nucleic acid molecule which a cell or virus that may synthesize
