"The Release of Energy in Food" PPT courseware download

Description

"The Release of Energy in Food" PPT courseware download

Part One: Course Knowledge Points

Knowledge point 1: Energy is stored in food

1. Explore the differences in energy storage between different foods

(1) Make a simple calorimeter by yourself. Two issues should be paid attention to when determining the production plan. One is how to ensure sufficient oxygen supply so that the sample can be fully burned; the other is how to reduce the energy loss during the sample combustion process as much as possible. Of the two calorimeters shown in the picture below, the one on the left is more suitable.

(2) Choosing the appropriate sample will help the experiment succeed, such as peanuts or walnuts. The sample must be able to burn; the burning process must be easy to operate.

(3) Reducing energy loss is the key to ensuring accurate experimental results.

(4) Experimental errors are inevitable. In order to improve the accuracy of experimental results, parallel repeated experiments were arranged for the selected samples when formulating the experimental plan.

(5) Experimental research shows that the mass of 1 mL of water is 1 g, and the heat required for each 1°C increase when heated is 4.187 J.

Error-prone reminder: The caloric value of food measured by a calorimeter will definitely be lower than the actual caloric content of the food; because no matter how the calorimeter is kept warm, some heat will always be lost to the air, and this part of the heat will not heat the water.

2. Hot price of food

The energy released when each gram of food is fully burned outside the body is the heat value of the food.

Knowledge point 2: Cells release energy through respiration

1. Examine the changes in the composition of human exhaled gas

(1) Take four bottles (250 mL) of the same size, labeled A, B, C, and D respectively.

(2) Open the bottle caps of A and B, place them in the air for 3 minutes and then close the bottle mouths. The gas composition in the bottle is the same as that of air.

(3) Exhale continuously into bottles C and D several times through the glass tube, so that the two bottles contain more gas exhaled from the lungs.

(4) Put the lit candles into bottles A and C (as shown in the picture above). The candle in bottle C is extinguished first.

(5) Pour 50 mL of clear lime water into bottles B and D respectively. The lime water in bottle D becomes turbid.

Experimental conclusion: The oxygen content in the air is higher than the air exhaled from the lungs; the carbon dioxide content in the air exhaled from the lungs is higher than the air.

2. Respiration

The process of oxidative decomposition and release of energy by glucose and other organic matter in living cells is respiration.

3. Utilization of energy

Part of the energy released by cells through respiration is used to maintain a constant body temperature, and the other part is used to promote various life activities. Therefore, the important significance of respiration is to provide power for life activities.

PPT on the release of energy in food, part 2 content: exam points

Test points: Analysis on measuring the stored energy of food

[Example] (2017·Guangdong Simulation) In the experiment of "exploring the difference in energy storage of different foods", Xiao Ming asked the question "Which one contains more energy, peanut kernels or walnut kernels?", which was incorrect in the plan he made. yes()

A. Add the same amount of water to both Erlenmeyer flasks

B. Install the experimental device before the experiment and measure the water temperature

C. Take a peanut kernel and a walnut kernel as experimental materials, and compare the difference in the increase in water temperature after burning

D. Repeat the experiment 3 times and take the average value for comparison.

Analytical control experiments can only have a single variable, and all other conditions are the same. In the "exploring the difference in energy storage of different foods" experiment, the experimental variables are the type of food, the materials and utensils used, the initial temperature and quality of water, the quality of different foods, etc. They should be exactly the same; repeat the experiment and take the average value to reduce the experimental error; the masses of "a peanut kernel and a walnut kernel" are not necessarily the same.

Answer C

PPT on the release of energy in food, part three: detailed explanation of textbook questions

Activity "Exploring the differences in energy storage between different foods" discussion question

1. Which food stores more energy (higher heat price)? What are the main nutrients of this food?

Tip: When peanuts and walnuts of the same mass are fully burned, the latter causes the water to rise to a higher temperature, so the walnuts store more energy. The main nutrients of walnuts are fat and protein.

2. What are the conditions to ensure that food can be fully burned outside the body?

Tips: Pay attention to the ventilation of the device (providing sufficient oxygen) is the main condition to ensure the complete combustion of food.

3. Compare the experimental results obtained by other groups measuring similar foods to evaluate the success and shortcomings of your group's activities.

Tip: Analyze based on actual situation. Key links: the rationality of the calorimeter, heat dissipation in the combustion process and other issues.

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.

"The Release of Energy in Food" PPT free download:

"The Release of Energy in Food" PPT free download Part 1: Learning objectives 1. The essence and significance of respiration. 2. Methods to detect oxygen and carbon dioxide. Important and difficult points 1. Key points: the essence and significance of respiration. 2. Difficulty: Detecting oxygen and dioxide...

"The Release of Energy in Food" PPT teaching courseware:

"The Release of Energy in Food" PPT teaching courseware Part One: Situation Introduction Where does the energy we need for life activities mainly come from? Learning objectives 1. Learn the basic methods of measuring food energy, and explain the commonalities and differences in the nature of combustion and respiration..

"The Release of Energy in Food" PPT download:

"The Release of Energy in Food" PPT Download Part One: Situation Introduction The Relationship between Exercise and Heart Rate What is the significance of increased heart rate and accelerated breathing during exercise? Question 1. Does food really contain energy? Do different foods contain the same amount of energy? 2.How to...

File Info

Update Time: 2024-07-09

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

Preview