Question

1) How does cellular respiration impact the observed rate of photosynthesis on algae beads?

2) look up current ocean pH values. How do the current values compare to those from previous years? Considering Algae beads how does the chemistry of the indicator used in photosynthesis vs. cellular respiration work? Hypothesize why oceans are at their current pH. How is the pH of the ocean changing and why? How might this affect the organisms that live in the ocean?

Answer 1

Photosynthesis is a biological process in which light energy is captured and then converted into organic compounds (glucose) in all organisms. These organic compounds rae used in Cellular respiration and converted into ATP. These two processes are mutually dependent on each other means that since the products of photosynthesis are act as a reactant for the respiration. The food which is prepared by the photosynthesis are used in the respiration for getting energy.

The pH scale, from 0 to 14, solutions which have low numbers are acidic and the solution with high numbers is basic. Whereas7 is considered as neutral. Before 300 million years ago, the pH of the ocean has been slightly basic, about 8.2. Today, it is 8.1, 0.1 pH units, shows a 25-percent increase in acidity in the past 2 centuries.

The algal beads which are encapsulated with sodium alginate are used for the examination of cellular respiration and rate of photosynthesis

As we know that algae are autotrophs so that they contains a chloroplast where photosynthesis takes place and mitochondria where cellular respiration occurs.

For the examination of cellular respiration and rate of photosynthesis the algae beads are incubates in a CO₂ indicator solution that is sensitive to pH change which is caused by CO₂ dissolution in water to form carbonic acid:

The time, at which CO2 indicator is shows stability with the atmosphere, it is dark orange after the increase in CO2 levels the colour of the solution changes into yellow, whereas as the CO2 levels decrease the colour of the solution changes into purple. The CO2 indicator also changes the pH range of the algae beads from pH 6.9 to pH 9.1 by which the rate of photosynthesis and cellular respiration can be measured.

By using a chemical called bromothymol blue (BTB). This is a chemical which is used in laboratory to test the pH change. You have to follow the following steps to analyze pH change in the ocean.

Take 50 ml of BTB solution in a beaker. Breathe out your CO₂ into the beaker. Be careful during the performing experiment. Observe the change in colour when colour is changed then you have to stop exhaling CO₂. Compare your color change.

As we know that the concentration of CO₂ is increase in the atmosphere this increased concentration of CO₂ may dissolved in and change the pH of the oceans.         

The change in the pH by increase CO₂ concentration may affect the organisms that live in the ocean because the living beings in the ocean are sensitive to pH like many living beings of the ocean are survives at acidic pH whereas many are at basic pH.