Assessment of Cellular Respiration in Germinating and Non-Germinating Peas Seeds

Assessmentof Cellular Respiration in Germinating and Non-Germinating Peas Seeds

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Assessmentof Cellular Respiration in Germinating and Non-Germinating Peas Seeds

Backgroundinformation

Cellsrequire energy to carry out the necessary metabolic reactions. Thisenergy is produced through the process of cellular respirationwhereby sugar, amino acids, and fats are broken down in the presenceof oxygen to yield CO2,water, and energy in the form of ATP. The reaction is as follows

C6H12O6+6O2 6CO2+6H20

Sincerespiration is exergonic, the heat produced can be used to measurethe process indirectly. Alternatively, O2consumption and CO2production levels can be monitored using a respirometer

RespirometerSetup, Components, and their Functions

Arespirometer works using the principle of ideal gas laws whereby nmoles of a gas are affected by changes in the variables temperature,pressure and volume and this is given by (PV = nRT ). A respirometeris therefore made up of a vial interconnected to a pipette. Insidethe vial is a respiration source such as a living organism orgerminating plant which can produce CO2and utilize O2.To deal with the two gas changes occurring simultaneously, KOH isadded in the vial to absorb any CO2 produced

CO2+ 2KOH –&gt K2CO3+ H2O

Theremaining oxygen can then be used as the only measurable variable inthe pipette readings.

Beadsare also added to ensure uniformity of volume in the respirometer.After, apparatus assembly, the respirometer is immersed in a jar ofwater or tracked with a dye to create a region of low pressure andhigh pressure. As O2 is consumed, the pressure of gasses inside therespirometer increases thus triggering water/dye to enter thepipette.

Objectives

Todetermine if the conditions under which respiration occurs.

Materials

Germinatingpea seeds, dry pea seeds, two respirometer vials, Weights for vials,stoppers, 1 ml graduated pipets cotton, pencil, water bath, ice,100 ml graduated cylinder, thermometer, masking tape, stopwatch orclock, water, potassium hydroxide, dye.

Procedure

Firstly,the pea seeds were weighed using the water displacement technique toensure equal volumes in the vials. The respirometers were then set upas required in the first respirometer, germinating pea seed wereadded whereas dry pea seeds were added to the second respirometer.The gas changes were then tracked using a dye and measured using aruler.

Results

. Time(minutes)

Total Distance travel the dye in soaked peas

Total Distance travel by the dye in dry peas

1

1cm

1.5cm

2

1.50cm

2cm

3

1.50 cm

2cm

4

1.6 cm

2.3cm

5

1.7cm

2.5cm

6

1.8cm

2.8cm

7

1,8cm

2.8cm

8

1.9cm

3.2cm

9

1.8cm

3.2cm

10

1.9cm

3.4cm

Presentationof Data

Fromthe graphical results, the distance the distance traveled by the dyeincreased slowly over time as compared to the distance traveled bythe dye in dry beans. This implies that dry beans utilized oxygenmore readily than soaked beans which are unlike. It is expected thatsoaked beans would use more oxygen for germination than dry beanswhich are dormant. Seeds contain an endosperm which acts as a sourceof nutrients to the seed. In the presence of water moisture warmthand other viable conditions, this seed can break down the food in theendosperm using enzymes to produce energy which is utilized forgermination

Conclusion

Theresults were unexpected maybe due to erroneous data collection ormislabeling of the respirometer vials.

Questions

Describethe process of fermentation

Fermentationis the breakdown of sugars into acids, gasses or alcohol as seen insome microorganism or oxygen deficient conditions as in lacticacidosis and usually accompanied by effervescence. The process isuseful in the manufacture of beer wine bread and other foodstuffs

Explainhow a fermentation tube measures fermentation

Fermentationtube measures the amount of CO2 produced during fermentation.

Interpretdata generated by a fermentation tube

CO2levels Correlates to the fermentation rate

Predictenvironmental factors that will alter the rate of fermentation

  • Ph

  • Temperature

Reference

Lab5 Cellular Respiration by Kris Layher.(2016). Biologyjunction.com.Retrieved 27 October 2016, fromhttp://www.biologyjunction.com/lab_5_cellular_respiration_by_kr.htm