Topic: Photosynthesis

Author: Elżbieta Szedzianis

Target group

7th grade student of elementary school.

Core curriculum

Cele kształcenia – wymagania ogólne

I. Znajomość różnorodności biologicznej oraz podstawowych zjawisk i procesów biologicznych. Uczeń:

2. wyjaśnia zjawiska i procesy biologiczne zachodzące w wybranych organizmach i w środowisku;

3. przedstawia i wyjaśnia zależności między organizmem a środowiskiem;

II. Planowanie i przeprowadzanie obserwacji oraz doświadczeń; wnioskowanie w oparciu o ich wyniki. Uczeń:

1. określa problem badawczy, formułuje hipotezy, planuje i przeprowadza oraz dokumentuje obserwacje i proste doświadczenia biologiczne;

2. określa warunki doświadczenia, rozróżnia próbę kontrolną i badawczą;

3. analizuje wyniki i formułuje wnioski;

III. Posługiwanie się informacjami pochodzącymi z analizy materiałów źródłowych. Uczeń:

2. odczytuje, analizuje, interpretuje i przetwarza informacje tekstowe, graficzne i liczbowe;

IV. Rozumowanie i zastosowanie nabytej wiedzy do rozwiązywania problemów biologicznych. Uczeń:

1. interpretuje informacje i wyjaśnia zależności przyczynowo-skutkowe między zjawiskami, formułuje wnioski;

2. przedstawia opinie i argumenty związane z omawianymi zagadnieniami biologicznymi.

Treści nauczania – wymagania szczegółowe

I. Organizacja i chemizm życia. Uczeń:

6. przedstawia istotę fotosyntezy jako jednego ze sposobów odżywiania się organizmów (substraty, produkty i warunki przebiegu procesu) oraz planuje i przeprowadza doświadczenie wykazujące wpływ wybranych czynników na intensywność procesu fotosyntezy;

8. przedstawia czynności życiowe organizmów.

Lesson objectives

Students describe the course and importance of photosynthesis and analyse the factors that influence its intensity.

The criteria for success

  • you will specify substrates, products and conditions of photosynthesis;

  • you will discuss the course of the experiment showing the effect of carbon dioxide concentration on the intensity of photosynthesis;

  • you will sing a chorus of a song about photosynthesis.

Key competences

  • communication in the mother tongue;

  • communication in foreign languages;

  • mathematical competence and basis competences in science and technology; 

  • digital competence;

  • learning to learn;

  • social and civic competences.

Methods/forms of work

Talk, working with the text, observation.

Individual activity and activity in pairs.

Teaching aids

  • abstract;

  • interactive whiteboard or traditional blackboard;

  • tablets/computers

  • 2 large jars;

  • bottle of carbonated mineral water;

  • bottle of non‑carbonated mineral water;

  • lamp with bulb 100W for lighting plants;

  • Canadian pondweed;

  • colourful cards to assess the degree of learning (table tents);

  • a clip to a song about photosynthesis from the Internet titled „Piosenka o fotosyntezie w Laboratorium „Runo Leśne” ;

  • lyrics of the song about photosynthesis.

Lesson plan overview

Introduction

1. The teacher prepares a jar, warm carbonated mineral water with temperature of 30°C and a seaweed. The teacher asks one of the students to read the information on the label of bottle with mineral water and then to pour it into the jar. The teacher emphasizes that the water contains carbon dioxide. The student puts a Canadian pondweed into the jar and places it in the light of a lamp used to light up the plants. The second jar is prepared analogously with non‑carbonated mineral water. The teacher asks the students to observe the seaweed during the classes.

2. The teacher specifies the subject and objectives of the lesson and the criteria for success. The teacher tells the students that they will learn about the process of photosynthesis, that is how the plants nourish. The teacher writes on the board a question “How do the plants nourish?”, a phrase “Difficult words” and below the term “photosynthesis”.

Realization

1. The teacher displays an ilustration entitled “Process of photosynthesis” (Appendix no.1) and together with the students analyses the subsequent stages of photosynthesis.

2. Working in pairs, the students draw a diagram of the photosynthesis process.

The teacher asks the students to complete the missing elements. The teacher introduces the terms of substrates and products of photosynthesis. The teacher writes the two terms on the board (under the phrase “Difficult words”).

4. Students look at a simplified record of the photosynthesis reaction in an abstract and then explain how the plants nourish.

5. The teacher discusses the illustration “Place where plants store reserve substances”. (Attachment 1.)

6. Students read a description of the experiment showing the effects of carbon dioxide concentration on photosynthesis intensity in the abstract. The students report on the course of the experiment
and the conclusions drawn from it.

7. The teacher asks the students to look at the seaweed put in the carbonated and non‑carbonated mineral water and describe the changes that have occurred in the jar during the classes. He asks students to count how many gas bubbles each plant in 5 minutes. He informs that the number of bubbles indicates the intensity of photosynthesis. Students supplement the observation diary.

Summary

  1. The teacher distributes the lyrics of the song about photosynthesis to the students and displays the clip from the Internet titled „Piosenka o fotosyntezie w Laboratorium „Runo Leśne”. The teacher encourages the students to transform the song into rap.

  2. With the use of green, yellow and red cards (table tents), the students assess the degree of assimilation of the information acquired during the classes.

Homework for the interested students

Students learn the lyrics of the song about photosynthesis.

Appendix

R2h1gRqVtfNdB

Pobierz załącznik

appendix no.1
Plik PDF o rozmiarze 29.71 KB w języku polskim
DT3e7uh9C

The following terms and recordings will be used during this lesson

Terms

chlorophyll
chlorophyll
RaFT0xlsiXrdQ
Nagranie dźwiękowe słówka chlorophyll

chlorofil – związek organiczny; zielony barwnik – główny składnik chloroplastów – umożliwiający wykorzystanie energii świetlnej w procesie fotosyntezy

chloroplast
chloroplast
R1Q7SvemS85qj
Nagranie dźwiękowe słówka

chloroplast – składnik organellum komórki roślinnej i glonów (samożywnych protistów) zawierający chlorofil, w którym zachodzi proces fotosyntezy

carbon dioxide
carbon dioxide
RcvGAhnx6TFnZ
Nagranie dźwiękowe słówka carbon dioxide

dwutlenek węgla – gazowy związek węgla i tlenu; substrat fotosyntezy, produkt oddychania komórkowego

photosynthesis
photosynthesis
R136asgk9AIiU
Nagranie dźwiękowe słówka

fotosynteza – proces syntetyzowania związków organicznych z dwutlenku węgla i wody, zachodzący w organizmach samożywnych pod wpływem światła, z udziałem chlorofilu i enzymów

products of photosynthesis
products of photosynthesis
R11v6vV7wtnf2
Nagranie dźwiękowe słówka products of photosynthesis

produkty fotosyntezy – tlen i różne związki organiczne, w tym glukoza, które powstają w wyniku procesu fotosyntezy

substrates
substrates
RfVFoaoq798dZ
Nagranie dźwiękowe słówka substrates

substraty – substancje, które wejdą ze sobą w reakcję chemiczną

substrates of photosynthesis
substrates of photosynthesis
RlZPB2AhKREWc
Nagranie dźwiękowe słówka substrates of photosynthesis

substraty fotosyntezy – woda i dwutlenek węgla; substancje chemiczne, które ulegają przemianie w trakcie procesu fotosyntezy

Texts and recordings

R1X8A99j8yI4P
Nagranie dźwiękowe dotyczące fotosyntezy

Photosynthesis

The main substances used by plants to produce nourishment are two simple inorganic compounds: water and carbon dioxide. Land plants take water from the soil and carbon dioxide – from the air. These compounds produce simple sugar – glucose. The process of converting water and carbon dioxide into glucose takes place in the presence of light, which is why it is called photosynthesis. The name of this process comes from the Greek words phos (light) and sýnthesē (creation).

Photosynthesis requires the green pigment – chlorophyll, which absorbs light, starting a series of chemical reactions. One of these is the decomposition of water into hydrogen and oxygen. Oxygen, as a by‑product, is excreted into the atmosphere, while hydrogen and carbon dioxide are used to produce sugars. The light energy is stored in the glucose molecules. All chemical reactions take place at the right rate thanks to specialised proteins – enzymes. The more intense the photosynthesis, the more organic substances the plants produce.

The rate of photosynthesis is influenced by both the external environmental conditions of plants and the elements of their internal structure. The intensity of this process depends on the amount and quality of light, the concentration of carbon dioxide in the air, the availability of water and mineral salts as well as the ambient temperature. Among the internal factors that determine the course of photosynthesis, the content of chlorophyll and enzymes is particularly important.

Carbon dioxide is the basic substrate of photosynthesis. Its concentration in the atmosphere is about 0.04%. The main source of this gas are the processes of decomposition of dead organic matter in the soil, carried out by bacteria and fungi. The amount of carbon dioxide in the air affects the intensity of photosynthesis – thus, an increase in its concentration leads to an increase in the mass of plants. However, the intensity of the process increases only up to a certain level of the plant’s saturation with this gas. Once this is achieved, a constant rate of photosynthesis is established, which depends on other factors, mainly on the rate of reaction carried out by the cellular enzymes.

Water - besides carbon dioxide - is the basic substrate used by plants to produce glucose. The water content in the plant affects the opening and closing of stomata – holes in a leaf skin leading to the space between the cells filled with chloroplasts. Significant water scarcity causes closing of the stomata, inhibits the supply of carbon dioxide and reduces the intensity of photosynthesis. Plants which are deprived of water for a long period would wilt and fade.

Together with water, a plant takes up the mineral salts necessary for its development. They are used to build organic compounds being part of the cells and regulate functioning of enzymes. The absence of mineral salts in the soil is a factor directly limiting photosynthesis. Nitrogen is necessary for building up of enzymes regulating this process. On the other hand, deficiency of magnesium, which is a component of chlorophyll, inhibits the synthesis of this pigment.

The main product of the photosynthesis process is glucose. This sugar, with the help of enzymes, is converted into other organic compounds such as starch, cellulose, fats and proteins, or is used as an energy source in the cellular respiration process. Plants use organic compounds, produced as a result of photosynthesis, to build cells and store energy. Excess of these substances is accumulated in roots, stems, leaves or seeds. When plants need glucose, they draw it from their reserves.

Oxygen is a by‑product of photosynthesis. During the day, plants produce much more oxygen than they need. Excess of this gas is released into the atmosphere through the stomata and used by plants and other organisms for breathing. Plants do not produce oxygen at night.

  • Photosynthesis is the process during which organic compounds and oxygen are formed from water and carbon dioxide – with the help of solar energy.

  • Organic substances produced during photosynthesis are nourishment for plants.

  • Oxygen from photosynthesis is used by plants and other organisms during respiration, and excess oxygen is released into the atmosphere.

  • Photosynthesis is carried out by organisms containing the green pigment – chlorophyll.