Answer to Question #12242 in Biochemistry for robin miller

Question

The breakdown of ATP releases energy, which is utilized by other reactions that require energy. Identify other examples where inventions have utilized a similar principle, where energy released during one reaction is utilized elsewhere. List three reasons why either one of the processes is more efficient than the other.

Answer 1

For instance, we get electricity, which is a secondary energy source, from the
conversion of other sources of energy, like coal, natural gas, oil, nuclear
power and other natural sources, which are called primary sources. The same
point there is with acting principle of steam locomotive and
engines.
Despite its negative image, nuclear energy may be the most
efficient and realistic means of meeting the rapidly-growing demand for power.
Why?
1)Thermal power plants generate electricity by burning fossil fuels
such as petroleum, coal and natural gas. This combustion process is the source
of CO2 emissions, which causes global warming.Nuclear power generation, in
contrast, harnesses the heat energy produced by nuclear fission. Because there
is no combustion involved in the process, nuclear power generation does not emit
CO2 in principle.
2)Furthermore, indirect CO2 emissions from processes such
as mining/transportation of fuels and development/operation of power stations
are miniscule. While a natural gas-fired combined cycle plant, which is the most
efficient power generation option, emits approximately 474g of CO2 to generate
1kWh of electricity, a nuclear power plant emits only about 20g of CO2 and can
generate the same amount of electricity.

3)For comparison, fossil-fuelled
power stations (and nuclear, for that matter) have an efficiency of about 33%.
In other words, about 1/3 of the heat energy released from the fuel gets turned
into electricity. The other 2/3 of the energy ends up as waste heat - it just
warms up the power station and its surrounding environment.

The maximum
theoretical thermal efficiency of a power station is around 64% (look up 'Carnot
Cycle'), but in real life the best thermal efficiency is around 42%. Various
other random heat losses eventually give you around 33% overall 'generation'
efficiency.