Vernier Software & Technology

# Cell Respiration (Pressure)

## Introduction

Cellular respiration refers to the process of converting the chemical energy of organic molecules into a form immediately usable by organisms. Glucose may be oxidized completely if sufficient oxygen is available and is summarized by the following reaction:

${{\text{C}}_{\text{6}}}{{\text{H}}_{{\text{12}}}}{{\text{O}}_{\text{6}}}{\text{ + 6 }}{{\text{O}}_{\text{2}}}{\text{(g)}} \leftrightarrow {\text{6 }}{{\text{H}}_{\text{2}}}{\text{O + 6 C}}{{\text{O}}_{\text{2}}}{\text{(g) + energy}}$

All organisms, including plants and animals, oxidize glucose for energy. Often, this energy is used to convert ADP and phosphate into ATP.

To measure the rate of cellular respiration, the pressure change due to the consumption of oxygen by peas will be measured with a Gas Pressure Sensor. It is not possible to directly measure pressure changes due to oxygen, since the Gas Pressure Sensor measures the total pressure change. Carbon dioxide is produced as oxygen is consumed. The pressure due to CO2 might cancel out any change due to the consumption of oxygen. To eliminate this problem, a chemical will be added that will selectively remove CO2. Potassium hydroxide, KOH, will chemically react with CO2 by the following equation:

${\text{2 KOH + C}}{{\text{O}}_{\text{2}}} \to {{\text{K}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{O}}$

This will allow you to monitor pressure changes exclusively due to the consumption of oxygen.

A respirometer is the system used to measure cellular respiration. Pressure changes in the respirometer are directly proportional to a change in the amount of gas in the respirometer, providing the volume and the temperature of the respirometer do not change. If you wish to compare the consumption of oxygen in two different respirometers, as we will in this experiment, you must keep the volume and temperature of the air equal in each respirometer.

Both germinating and non-germinating peas will be tested. Additionally, cellular respiration of germinating peas at two different temperatures will be tested.

## Objectives

In this experiment, you will

• Measure gas production.
• Study the effect of temperature on cell respiration.
• Determine whether germinating peas and non-germinating peas respire.
• Compare the rates of cell respiration in germinating and non-germinating peas.

## Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

### Option 2

You may also need an interface and software for data collection. What do I need for data collection?

## Advanced Biology with Vernier

See other experiments from the lab book.

 1A Diffusion through Membranes 1B Osmosis 2A Enzyme Action: Testing Catalase Activity 2B Enzyme Action: Testing Catalase Activity 3 Mitosis & Meiosis 4A Plant Pigment Chromatography 4B Photosynthesis 5A Cell Respiration (CO2 and O2) 5B Cell Respiration (CO2) 5C Cell Respiration (O2) 5D Cell Respiration (Pressure) 6A pGLO™ Bacterial Transformation 6B Analysis of Precut Lambda DNA 6B Forensic DNA Fingerprinting 7 Genetics of Drosophila 8 Population Genetics and Evolution 9 Transpiration 10A Blood Pressure as a Vital Sign 10B Heart Rate and Physical Fitness 11 Animal Behavior 12A Dissolved Oxygen in Water 12B Primary Productivity 13 The Visible Spectra of Plant Pigments 14 Determination of Chlorophyll in Olive Oil 15 Enzyme Analysis using Tyrosinase 16 Introduction to Neurotransmitters using AChE 17 Macromolecules: Experiments with Protein

### Experiment 05D from Advanced Biology with Vernier Lab Book

#### Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.