Topic: What is breathing?

Supplementary material for use in lessons in the group of natural sciences (nature, biology, chemistry, geography, physics), additional classes, science clubs. It can serve as a resource for expanding knowledge, preparing students for science competitions.

Target group

5th‑grade students of elementary school (biology).

Core curriculum

5th grade of elementary school biology
I. Organization and chemism of life. Student:
7) presents aerobic respiration and fermentation as ways of producing energy needed for life (substrates, products and process conditions), and plans and conducts experiments showing that during fermentation yeast secrete carbon dioxide;

General aim of education

Students demonstrate experimentally that the necessary element for combustion is oxygen, they identify products of combustion and breathing.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• explain what is cellular respiration;

• demonstrate experimentally that oxygen is needed for combustion;

• detect cellular respiration products: carbon dioxide and water.

Methods/techniques

• activating

  • discussion.

• expository

  • talk.

• exposing

  • film.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers.

Lesson plan overview

Before classes

• Students get acquainted with the content of the abstract. They prepare to work on the lesson in such a way to be able to summarize the material read in their own words and solve the tasks themselves.

Introduction

• The teacher refers to the knowledge from previous lessons by formulating questions that are answered by selected/willing students:

  • Explain why human breathes?

• The teacher gives the topic, the goals of the lesson in a language understandable for the student, and the criteria of success.

Realization

• The teacher asks students to read the first paragraph from the abstract. What is burning and how to copy to the notebook the explanation of what combustion is and what accompanies it. An eager student reads an explanation.

• The teacher displays the first part of the film to the students, the students write the answers to the questions. The selected pupil reads the answers, the teacher corrects their correctness, and if necessary, plays the film again.

• The teacher asks students to read the second paragraph Cellular respiration from the abstract and write to the notebook an explanation of what cellular breathing is. An eager student reads an explanation.

• The teacher displays the second part of the film to the students, the students write observations. The teacher corrects the correctness of the speech, possibly playing the film again.

• The teacher asks students to look at the whole film Detect cellular respiration products and then perform the interactive task themselves.

• The teacher displays students' graphics The composition of the inhaled and exhaled air , the students present their observations.

Summary

• The teacher asks students to carry out the recommended interactive exercise themselves.

Homework

• Listen to the abstract recording at home. Pay attention to pronunciation, accent and intonation. Learn to pronounce the words learned during the lesson.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

What is breathing?

To understand what breathing is all about, we need to find out what combustion is. It is a chemical reaction of various substances with oxygen, during which energy is released – that is why we feel warmth and see light. Combustion enables us to obtain the energy needed to heat a home and cook a meal. To release the energy contained in wood, for example, oxygen from the air is required. We will prove it by performing an experiment.

In the human body a process takes place by which cells use oxygen to break down food molecules to release their stored energy. This process occurs in every cell of the body and this is why it is called cellular respiration. It is typical for all living organisms. In most of them, oxygen is involved in this process. Cellular respiration is very similar to combustion, but there are two important differences:

• cellular respiration does not occur as rapidly as combustion;

• the energy produced from respiration does not dissipate in the form of light and heat, but is stored by the body.

The nutrients involved in the process of cellular respiration mainly include sugars and fats. Therefore, foods rich in these nutrients are called energy‑yielding foods. Both nutrients and oxygen are transported to the cells by the blood. As a result of cellular respiration, energy is released; and by‑products are also produced: carbon dioxide and water. The body uses energy for various life processes, e.g. moving, maintaining body temperature or growth. Carbon dioxide is removed during gas exchange, while water can be used up by the body.

The air consists mainly of nitrogen and oxygen. It also contains small amounts of carbon dioxide and other gases. Of these ingredients, only oxygen supports the combustion process and is used during cellular respiration. The content of oxygen in exhaled air decreases because a part of it was used to break down food nutrients. Instead, there is more carbon dioxide and water (in the form of water vapour) – substances produced as a result of cellular respiration. The amount of other air components does not change.

• During combustion of substances, heat and light are released. Combustion usually takes place in the presence of oxygen.

• During cellular respiration, the energy contained in the food is released in the presence of oxygen. Unlike the combustion process, it is a gradual process, in which energy is stored and then it is utilized to perform various life activities.

• Exhaled air contains less oxygen and more carbon dioxide and water vapor than inhaled air.