Biology presentation

Respiration in Plants

Contents

Presentation on Respiration in Plants

Acknowledgement

Introduction

Acknowledgement

What is respiration?

Important characteristics of respiration

ATP and its importance

Comparison and difference of burning and respiration

Parts of the plants respires

Kinds of respiration

Difference between aerobic and anaerobic respiration

Experiments on respiration in plants

Bibliography

Conclusion

Introduction

Anurag Chakraborty

STD. – VIII B

Roll # 28

Little Flower School

Burning of Food

I Anurag Chakraborty of class VIII-B would like to take the opportunity of acknowledging my heartfelt gratitude and indebtness to Mrs. Charu Jain, my Biology teacher who has been so supportive and the source of inspirations. She is a kind teacher who is always ready to help a student who want to learn and I believe that she makes complex concepts simple and easy.

I would like to give a special thanks to my parents who have been by my side all times and because of their support I am able to complete the assessment. They helped me to collect all the required materials.

What is Respiration?

A demonstration of energy released from food

Like all other organisms, plants needs energy for carrying out body activities. Here we will learn about the two kinds of respiration (aerobic and anaerobic), the manner in which diffusion of respiratory gases occurs.

oxygen

food (sugar)

a process of oxidizing food to release energy inside cells

Burning

energy

carbon dioxide

water

Respiration in Plants

When energy in the form of ATP is used, the ATP is converted to ADP (adenosine diphosphate) and again when more energy is available by further breakdown of glucose, the ADP is reconverted to ATP and so it goes on.

One mole of glucose on complete oxidation yields 38 molecules of ATP.

Respiration

Three important characteristics of respiration equation

food(sugar) + oxygen

Chemical Structure of ATP

reactions are catalyzed by enzymes

main food substance which oxidized in cells is glucose

The breakdown of glucose (C6H12O6) to carbon dioxide and water does not occur in a single step but in a series of chemical steps. These steps occur in two major phases:

Glycolysis (glucose – pyruvate) occuring in cytoplasm and

Krebs cycle (pyruvate --- CO2 + 6H2O + ATP) occuring in mitochondria.

Each breakdown step is due to particular enzyme.

The energy liberated in the breakdown of the glucose molecule is not all in the form of heat, but a large part of it is converted into chemical energy in the form of ATP – a chemical substance called adenosine triphosphate.

Why ATP is Known As Energy Currency of the Cell?

carbon dioxide + water + energy (heat + light)

Because it supplies ENERGY to the living cells

does not occur in living cells because the reaction is too fast and cells would die as they become so hot

CO2

H2O

ENERGY

enzymes

C6H12O6

+ 6O2

+ energy

6CO2

+ 6H2O

HEAT

as it takes place in all living cells, it is called cellular respiration which is used to produce energy for cells to use

PHOSPAHE

ADP

ATP

PHOSPAHE

ENERGY USED IN WORK

Respiration in Plants

Living organisms show two types of metabolic activities:

Anabolic (constructive or biosynthetic processes), it consumed energy.

Catabolic (destructive or breaking down processes), it gives out energy for use by the organism.

Differences

The Entire Plant Respires

Comparison of Burning and Respiration

Three inlets through which the plants obtain oxygen from the atmosphere are:

Stomata in leaves

Lenticels in stem

General surface of the roots

During daytime, in photosynthesis, the leaves produce oxygen, some of which is used in respiration and the rest is diffused out. The carbon dioxide produced during respiration in the leaves serves as a raw material for photosynthesis.

Burning

Respiration

There are two kinds of respiration

Burning

Respiration

Similarities

- both involve oxidative processes

- both require the use of oxygen and food and they produce the same products of carbon dioxide and water

- both reactions release energy

energy release is vigorous and not under control

energy release is slower and under control

takes place in air or oxygen

takes place in cells

Aerobic Respiration

Anaerobic Respiration

a series of chemical reactions

a single-step process

energy is released in form of heat and light (a flame can result)

energy is released in form of heat and an energy-rich compound

no enzymes involved

controlled by enzymes

Respiration in Plants

Experiments on Respiration in Plants

Experiment to prove that oxygen is used up in respiration

The apparatus shown in the sketch is arranged for the above experiment. Flask (A) contains germinating bean seeds and Flask (B) has dead (boiled) seeds together with some antiseptic to avoid bacterial decay. Wet cotton provided water to boiled samples. A small tube containing soda lime (a mixture of sodium hydroxide and slaked lime) is suspended in each flasks for absorbing any carbon dioxide released by the seeds. After a few days, the delivery tube connected with flask (A) will show a greater rise in water level. When burning paper is introduced in to each flask after removing their corks, the flame is immediately put of in flask (A) but it continues for a short while in flask (B). This proves that oxygen is absent in flask (A) showing thereby that it was used up by germinating seeds and the volume of oxygen so used up was indicated by the rise of water level in the delivery tube.

Experiment to prove that carbon dioxide is produced during respiration in plants

Two flasks (A) and (B) are taken as shown in the sketch. Some wet cotton wool placed at the bottom of each flasks. Soaked seeds (such as pea or gram) are placed in flask (A) and an equal number of boiled (dead) seeds are placed in flask (B) as shown.

A little antiseptic (such as carbolic acid) is added to flask (B) to prevent bacterial growth on dead seeds, which would otherwise respire and release carbon dioxide. The flasks are securely corked and left in similar conditions of light and temperature. A few days later, the seeds in flask (A) will be found to have clearly germinated and those in flask (B) showing no sign of any germination (as they are dead). The gases in each flask are then tested by removing the cork and tilting the flask over a test tube containing limewater and then shaking up the test tube. The expected gas carbon dioxide being heavier than air would “flow down” into the test tube.

Experiment to prove that carbon dioxide is produced by green plants during respiration

An apparatus is set up as shown in the sketch using a small potted plant Geranium. The bell-jar should be placed on a glass sheet and its rim as well as all other connections should be vaselined to make them air tight. The outside air is drawn into the apparatus with the help of an air pump. This air passes through the soda-lime which absorbs any carbon dioxide present in the incoming air, and the limewater (Flask A) through which it passes will not turn milky. As the air leaves the bell-jar, and passes through another sample of limewater (Flask B), the carbon dioxide present in it would turn the limewater milky. This experiment proves that carbon dioxide is produced by green plants during respiration. It is necessary that this experiment is carried out in the dark to prevent photosynthesis.

Anaerobic Respiration

Aerobic Respiration

Sometimes certain parts of the plants (including fruits and seeds) may temporarily respires even in the absence of oxygen. In this type of respiration the glucose molecule is incompletely broken down into ethanol (ethyl alcohol) and carbon dioxide with the release of a small quantity of energy. This type of respiration is called anaerobic respiration (or anoxybiotic) as it proceeds without oxygen. Certain microscopic organisms such as certain bacteria and fungi which normally respire only anaerobically.

anaerobic respiration

aerobic respiration

Free oxygen is used in respiration and there is a complete oxidation of glucose with the formation of carbon dioxide and water as end products. Respiration proceeds only when oxygen (a constituent of air) is available and is therefore called aerobic (or oxybiotic) respiration.

amount of energy released

large

small

oxidation of glucose

C6H12O6

+ 6O2

+ 38 ATP

completely

partly

6CO2

+ 6H2O

C6H12O6

(Glucose)

+ 2 ATP

+ 2CO2

2C2H5OH

place of occurrence

mitochondria

cytoplasm

The gas from Flask (A) would turn the limewater milky, showing the presence of carbon dioxide in it, while the gas in flask (B) will show no effect.

Therefore, the conclusion is that the germinating (respiring) seeds give out carbon dioxide.

Respiration in Plants

Bibliography

Conclusion

This assessment is very simple and interesting. In fact the science itself is very interesting if we correlate it with our day to day life. I have enjoyed a lot while making this assessment as I have gone through so many experiments on this assessment by studying many things on the net and given in books.

I would like to give a special thanks to my Biology teacher Mrs. Charu Jain for giving me such a nice assessment topic.

I have collected information’s from my text book ICSE Concise Biology and from the internet site, www.wikipedia.com to complete my assessment. This project have not only given me information about plants and its respiration processes but also its applications in our day to day life.

Thank You

Biology presentation

Anurag Chakraborty