How can cellular respiration be measured

Apply your knowledge from mouse experiments and of glycolysis, the Krebs cycle and the electron transport chain to help basketball players perform their best during their game.

Help Center Live chat Live chat Login. Cellular Respiration: Measuring energy consumption during exercise Virtual Lab Help basketball players understand how the food they eat gets converted to energy through glycolysis, the Krebs cycle and the electron transport chain. Try our lab safety simulation. Description Features. About the Cellular Respiration: Measuring energy consumption during exercise Virtual Lab What does it mean to work up an appetite? Evaluate cellular respiration through exercise Beginning by outlining the structural changes that take place during phosphorylation and glycolysis, you will identify the important products of the Krebs cycle and follow their electrons through the electron transport chain.

Respirometry and blood sample analysis You will measure cellular respiration by analyzing the blood glucose and lactic acid concentrations of basketball players throughout their game. Next, pyruvate molecules enter the mitochondria to take part in a series of reactions called the Krebs cycle, also known as the citric acid cycle. This completes the breakdown of glucose, harvesting some of the energy into ATP and transferring electrons onto carrier molecules.

In the last stage, known as oxidative phosphorylation, electrons pass through an electron transport system in the mitochondrial inner membrane, which maintains a gradient of hydrogen ions.

Cells harness the energy of this proton gradient to generate the majority of the ATP during aerobic respiration. Aerobic respiration requires oxygen, however, there are many organisms that live in places where oxygen is not readily available or where other chemicals overwhelm the environment. Extremophiles are bacteria that can live in places such as deep ocean hydrothermal vents or underwater caves.

Rather than using oxygen to undergo cellular respiration, these organisms use inorganic acceptors such as nitrate or sulfur, which are more easily obtainable in these harsh environments. This process is called anaerobic respiration. When oxygen is not present and cellular respiration cannot take place, a special anaerobic respiration called fermentation occurs. Fermentation starts with glycolysis to capture some of the energy stored in glucose into ATP.

However, since oxidative phosphorylation does not occur, fermentation produces fewer ATP molecules than aerobic respiration. In humans, fermentation occurs in red blood cells that lack mitochondria, as well in muscles during strenuous activity generating lactic acid as a byproduct, therefore it is named lactic acid fermentation.

Some bacteria carry out lactic acid fermentation and are used to make products such as yogurt. In yeast, a process known as alcoholic fermentation generates ethanol and carbon dioxide as byproducts, and has been used by humans to ferment beverages or leaven dough.

Cellular respiration together with photosynthesis is a feature of the transfer of energy and matter, and highlights the interaction of organisms with their environment and other organisms in the community. Cellular respiration takes place inside individual cells, however, at the scale of ecosystems, the exchange of oxygen and carbon dioxide through photosynthesis and cellular respiration affects atmospheric oxygen and carbon dioxide levels. Interestingly, the processes of cellular respiration and photosynthesis are directly opposite of one another, where the products of one reaction are the reactants of the other.

Photosynthesis produces the glucose that is used in cellular respiration to make ATP. This glucose is then converted back into CO 2 during respiration, which is a reactant used in photosynthesis.

More specifically, photosynthesis constructs one glucose molecule from six CO 2 and six H 2 O molecules by capturing energy from sunlight and releases six O 2 molecules as a byproduct. Cellular respiration uses six O 2 molecules to convert one glucose molecule into six CO 2 and six H 2 O molecules while harnessing energy as ATP and heat. Scientists can measure the rate of cellular respiration using a respirometer by assessing the rate of exchange of oxygen. Understanding the Ideal Gas Law is of fundamental importance for knowing how the respirometer functions.

The Ideal Gas Law states that the number of gas molecules in a container can be determined from the pressure, volume, and temperature.

More specifically, the product of the volume and pressure of a gas equals the product of the number of gas molecules, the ideal gas constant and the temperature of the gas.

Respirometers contain potassium hydroxide which traps carbon dioxide that is produced by respiration in solid form as potassium carbonate. When cells consume oxygen, the gas volume in the respirometer system decreases with no carbon dioxide to increase it back up, allowing scientists to calculate the amount of oxygen used using the ideal gas equation. To be able to compare results we need to ensure that control variables are kept the same during the experiment. Name two control variables for the experiment above.

Two from:. In an experiment, Sarah found that 1 g of yeast produced 20 cm 3 of carbon dioxide in three minutes when using glucose as a substrate. What was the rate of respiration in cm 3 of CO 2 per minute when using glucose? The rate needs to be calculated in cm 3 of CO 2 per minute. We know that 20 cm 3 of CO 2 was produced in three minutes. To calculate the rate of CO 2 produced per minute we need to divide the volume of CO 2 produced by the time it took to produce that volume of CO 2.

Using the table below, which substrate was the best for the yeast in terms of releasing energy quickly? Explain your answer.