Cellular Respiration and Photosynthesis co-exist as paired processes

							Cellular Respiration and Photosynthesis co-exist as paired processes. Photosynthesis
converts light energy into organic molecules such as carbohydrates. These molecules
are picked up and utilized as fuel sources in organisms that employ Cellular
Respiration for production of ATP and CO2.

1. Create a table comparing and contrasting the two processes.

2. Please provide a hypothesis and suggest an experiment to test the relationship
between mtDNA and human ageing. Propose a direction for future research and
drug development for targeting mtDNA to combat the aging process.


1. Create a table comparing and contrasting the two processes.


Solution:


Cellular Respiration and Photosynthesis:


“The process of photosynthesis makes glucose. Releasing the spring is like cellular
respiration.”


Photosynthesis is a biochemical process in which plants, algae, and some bacteria harness
the energy of light to produce food. Ultimately, nearly all living things depend on energy
produced from photosynthesis for their nourishment, making it vital to life on Earth. It is
also responsible for producing the oxygen that makes up a large portion of the Earth's
atmosphere. –source 1 & 2


Cellular respiration allows organisms to use (release) the energy stored in glucose. The
energy in glucose is first used to produce ATP. Cells use ATP to supply their energy
needs. Cellular respiration is therefore a process in which the energy in glucose is
transferred to ATP.

Photosynthesis and respiration are reactions that are opposite to each other.
Photosynthesis is a process where food or sugar is formed by absorption of energy and
respiration is a process where food or sugar is broken down and energy is released.
Source 3
The differences between photosynthesis and respiration are:



             Photosynthesis                                    Respiration

Photosynthesis produces food                   Respiration breaks down food

In photosynthesis carbon dioxide combines In respiration glucose is broke down into
with water to produce glucose             carbon dioxide and water

Photosynthesis absorbs sun’s energy            Respiration releases energy trapped in food
                                               or glucose

Photosynthesis takes place in the presence No catalyst is needed for respiration
of a catalyst chlorophyll

CO2 is absorbed in photosynthesis              CO2 is released in respiration

Oxygen is released in photosynthesis           Oxygen is absorbed in respiration

Photosynthesis has to take place in sunlight Respiration does not need sunlight


Photosynthesis occurs only during daytime Respiration occurs at all times during the
                                          lifetime of the living cell

Source 3


2. Please provide a hypothesis and suggest an experiment to test the relationship
between mtDNA and human ageing. Propose a direction for future research and drug
development for targeting mtDNA to combat the aging process.
Solution:
Experiment:

Title:

Drug development for mtDNA to combat the ageing process and finding
         the relationship between mtDNA and ageing process
Aim:

To test the relationship between mtDNA and human ageing process as well as Drug
development for mtDNA to combat the ageing process.

Source 4 gave the idea, source 5 facilitated
Hypothesis: - taken from source 5 and checked with source 4

“Contribution of mitochondrial DNA (mtDNA) mutations to the human ageing process
is reviewed and the implications for cellular bioenergy loss and pharmacological
therapy (Drug development). Mitochondrial DNA mutation and the ageing process help us
to understand the relationship between mtDNA and ageing process.”


The central idea is that random mutations in the population of mtDNA molecules of each
cell occur throughout life, and that this is a major contributor to the gradual loss of
cellular bioenergy capacity within tissues and organs, associated with general senescence
and diseases of ageing. An elaboration of four major aspects of the general proposition,
together with relevant supporting data, is presented.

      An extensive array of deletions in mtDNA of many tissues of humans and other
       mammals has been observed to occur in an age-related manner.

      The preservation and selection of fully functional mtDNA molecules in the
       female germ line cells is proposed to occur via a human mtDNA cycle, in which
       selective amplification of a limited number of mtDNA templates occurs during
       oocyte development. The phenomena of maternal inheritance and rapid fixation of
       sequence variants of mtDNA in mammals, as well as selection of cells based on
       mitochondrial function, are taken into account.

      Tissue bioenergy mosaics result from accumulated mtDNA damage during
       ageing, representing different rates of cellular bioenergy loss within individual
       cells of a tissue. The random segregation of mtDNA during cell division will also
       further contribute to the tissue energy mosaic. Cells unable to meet their particular
       bioenergy demand will become non-functional, leading to cell death; the
       bioenergy threshold is different for the various cell types in the tissues of the
       body.

      In order to bioenergetically resuscitate cells and tissues suffering from impaired
       mitochondrial functions as a result of the ageing process, we propose that redox
       compounds may be used therapeutically in the pharmacological configurations of
       a by-pass strategy or as a redox sink therapy.

        The role of these compounds is to maintain at least part of the mitochondrial
respiratory chain function (by-pass) as well as to maintain adequate levels of cellular
NAD+ (redox sink) for ATP synthesis, predominantly by the cytosolic glycolytic
pathway, with some contribution from mitochondrial oxidative phosphorylation.
Sources:
1. Wikipedia – photosynthesis:
http://staff.science.uva.nl/~hansmatt/documenten/Photosynthesis.htm


2. Keystone Curriculum – photosynthesis and cellular respiration
http://www.keystonecurriculum.org/html/photo_cell_respiration.html


3. ATT - photosynthesis and respiration and their differences
http://home.att.net/~cat6a/fuels-XI.htm


4. Blackwell Synergy – relationship between mtDNA and ageing process
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1474-
9726.2006.00209.x?cookieSet=1&journalCode=ace


5. NCBI – quote “Contribution of mitochondrial DNA (mtDNA) mutations to the human
ageing process….” and hypothesis
http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&uid=1383761&cmd=showdetailvi
ew&indexed=google