"The Release of Energy in Food" PPT courseware

Description

"The Release of Energy in Food" PPT courseware

Part One: Energy stored in food

Purpose

Learn how to measure food energy and understand the commonalities and differences between combustion and respiration.

laboratory apparatus

Alcohol lamp, Erlenmeyer flask, balance

Thermometer homemade measuring instrument

Matches Food Asbestos Net

Experimental steps

1. Weighing

2. Heating (measure the temperature before and after)

3. Weighing

4. Calculation

Precautions

1. The burned food is first placed on an asbestos net to cool down and then weighed.

2. Do not let the lower end of the thermometer touch the bottom of the bottle.

3. Check the thermometer a few seconds before and after burning food.

PPT on the release of energy in food, part 2: Cells release energy through respiration

Demonstration experiment

Experiment name: Testing changes in the composition of human exhaled gas

Purpose of the experiment: By detecting changes in the composition of human exhaled gas, students can intuitively feel the current status of the changes. Also learn that cells release energy through respiration.

Experimental equipment and utensils: straws (2), glass bottles (4), candles (2), burning spoons (2), clarified lime water.

Experimental steps:

1. Take four bottles of the same size, labeled A, B, C, and D respectively.

2. Ask a student to place bottles A and B outside, open the bottle caps, and cover the bottle mouths after 3 minutes.

The gas composition in the bottle is the same as that of air.

3. Ask a student to take a straw and insert it into bottles C and D in sequence, exhale continuously into the bottle through the straw for several minutes, and then close the bottle mouth tightly.

The gas in the bottle contains more gas exhaled from the lungs.

4. Put the burning candles into bottles A and C respectively (such as textbook P51), and record the burning time of the candles. Phenomenon

5. Pour 10 mL of clear lime water into B and D respectively, and compare the turbidity of the liquids in the two bottles. Phenomenon

Experimental discussion:

1. Is there a difference in the gas composition between bottles A and C? Please state the basis for the experimental testing.

Answer: There are differences. Because the candle burns longer in bottle A than in bottle C, it means that the oxygen content in the air is higher than the gas exhaled from the lungs.

2. Is there a difference in the gas composition in bottles B and D? Please state the basis for the experimental testing.

Answer: There are differences. Because equal amounts of clear lime water are poured into bottles B and D respectively, the lime water in bottle D becomes obviously turbid, indicating that the carbon dioxide content of the exhaled gas from the lungs is higher than that of the air.

PPT on the release of energy in food, part three: teaching summary

Through demonstration experiments, we understood the reason why the oxygen content in the air exhaled from the lungs will decrease and the carbon dioxide content will increase.

Understand the concept, essence and significance of respiration.

Compare the respiration of human cells with the research activity "Food Burning Outside the Body" from the previous class. What are the similarities and differences between them?

Similarities: From the comparison of conditions and products, we found that they both require oxygen, the products are all carbon dioxide, and there is also the release of energy.

After comparison, it can be seen that the essence of these two processes is the same, that is to say, the essence of respiration is to decompose organic matter and release energy. Organic matter + oxygen → carbon dioxide + water + energy

Difference: From the perspective of the energy release process, the combustion process is very violent and the energy is released instantly. The release of cellular respiration energy is a continuous and slow process.

Is the process of releasing energy from food burning possible in the human body? If it happens, what impact will it have on human life activities?

Keywords: Beijing Normal University Edition Biology PPT courseware for seventh grade volume 2 free download, PPT download on the release of energy in food, .PPT format;

For more information about the PPT courseware "Energy Supply of the Human Body and the Release of Energy from Food", please click the "Energy Supply of the Human Body ppt Release of Energy from Food" ppt tag.

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Update Time: 2024-07-11

This template belongs to biology courseware Beijing Normal University Edition Seventh Grade Biology Volume 2 industry PPT template

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