Notes on "Example of Material Transmembrane Transport" in Senior High School Biology Teacher Recruitment Interview

20 17 Notes on Trial Lecture of Senior High School Biology Teacher Recruitment Interview "Examples of Transmembrane Transport of Substances"

The combination of basic theories of pedagogy and discipline with interview has gradually become the proposition scope of teacher recruitment examinations in various places. Then, the following is a trial lecture on "Examples of Transmembrane Transport of Substances" compiled by me for you. Welcome to read and browse.

First of all, talk about textbooks.

The example of transmembrane transport of substances is the content of section 1 chapter 4 1 of the new compulsory biology course for senior high schools published by People's Education Press. This section is based on? Problem discussion? The table shows the experimental phenomenon of osmosis, and students can understand the function of semi-permeable membrane by analyzing the phenomenon. And then through analysis? Water in and out of red blood cells? Phenomenon and exploration? Water loss and water absorption of plant cells? Make students realize that both cell membrane and protoplasm layer are equivalent to semi-permeable membranes; Finally, through the example of ion transport, it is recognized that cell membrane is a selective permeable membrane. Among them, what is this section Study on water absorption and water loss of plant cells? It's the first in the book. Exploring? Activity, through this activity, students can gain some experience and understanding in asking questions, making assumptions, designing experiments and other links, and lay a certain foundation for the later inquiry activities.

Second, talk about learning.

The teaching object of this section is senior one students. In junior high school, students' understanding of material exchange is still very superficial. Through the study of the previous chapters, students have mastered the structure of cell membrane and the basis of water transmembrane transport, which laid a cognitive foundation for the study of new knowledge and also possessed certain cognitive ability. The purpose, continuity and logic of thinking have also been initially established. Students have the foundation of autonomy, cooperation and inquiry, but they are often confused about the purpose, process and conclusion of inquiry.

Third, talk about teaching objectives.

Knowledge and Skills Objectives Based on the research on water absorption and water loss of animal cells, we will continue to explore the experimental design and operation of water absorption and water loss of plant cells.

Process and method objectives try to ask questions and make assumptions from life phenomena; Learn the general methods and steps of scientific inquiry.

The goal of emotion, attitude and values is to understand the thinking method of scientific inquiry, improve the ability to solve practical problems with knowledge, and develop the quality of interacting with others and learning from others. Initially formed a scientific attitude of seeking truth from facts and a certain spirit of exploration and innovation.

Fourthly, the difficulties in teaching.

Pay attention to the general process of scientific inquiry.

Try to ask questions and make assumptions; The experimental design and operation to explore the water absorption and water loss of plant cells were carried out.

Verb (abbreviation for verb) talks about teaching methods.

Teaching methods: problem-oriented learning method, group discussion method, multimedia intuitive teaching method, lecture method, etc. Learning method: analysis, observation and discussion in the study group? Autonomy, cooperation and exploration? Learning mode.

Sixth, talk about the teaching process.

(A) contact life, the introduction of new courses

First of all, briefly review the principles and laws of water absorption and dehydration of animal cells learned in the last class, and then connect with real life: in daily life, cabbage will wither when put in salt water for a long time; And the aunt who sells vegetables often sprinkles water on the vegetables, and the vegetables become strong? What biological principles do these life phenomena illustrate?

It is easy for students to say that animal cells absorb water and lose water: these phenomena show that plant cells also absorb water and lose water.

(B) new curriculum teaching

Continue to doubt: is the water absorption and dehydration of plant cells the same as that of animal cells To solve this problem, we must first analyze the structure of animal and plant cells. Convenient ppt shows the structural diagram of plant cells, and guides students to tell the biggest difference between the two structures: (the outermost layer of plant cells has a cell wall, and mature plant cells have a central vacuole), and at the same time leads to? Protoplast? This concept. Guide students to understand the concept of cytosol and its relationship with vacuoles, and lay the foundation for students to make reasonable and scientific assumptions smoothly.

Then, lead the students to think: if we want to study how plant cells absorb water and lose water, what is the core problem? Inspire students to ask questions: Is the protoplasm layer in plant cells also equivalent to a semi-permeable membrane?

It is valuable to guide students to analyze the above problems, and then to guide students to make bold guesses and give scientific basis. (Because cell membrane and vacuole membrane belong to biomembrane, which are very similar to the cell membrane of red blood cells in composition and structure, the protoplasm layer composed of cell membrane, vacuole membrane and cytoplasm between these two membranes should also be semi-permeable, equivalent to semi-permeable. )

Suppose that the protoplasm layer is equivalent to a semi-permeable membrane.

According to the group before class, discuss the basic ideas of the experiment in groups, and the teacher will patrol. Then the representative of the group speaks and guides other groups to continue to speculate on the expected results of the experiment according to the design ideas of the students in this group.

The teacher further led the group to further discuss the specific experimental scheme of the experiment, including the selection of experimental materials, experimental equipment and basic steps. Teachers' patrol guidance.

After the discussion, the group representatives spoke; Teachers guide other groups to evaluate the group's plan and put forward opinions. The teacher emphasized the choice of experimental materials: the best material is colored with a large central vacuole, and the best material is the skin of purple onion scales; It is emphasized that the control experiment before and after is more conducive to observing the dynamic changes of cell morphology.

Guide the students to refer to the operation steps in the textbook, combine the experimental scheme, operate the experiment in groups, observe the experimental phenomena and record the experimental results, and complete the following table.

Teachers' patrol guidance.

The representative of the group introduced the experimental results.

The teacher guided the students to analyze the experimental results, and reached the final experimental conclusion: protoplast is equivalent to a semi-permeable membrane, plant cells and animal cells have the same principle of water absorption and water loss, and water flows along the relative content gradient.

(3) Consolidate and improve

Back to the real life problems before class, students use what they have learned in this section to explain further. This will cultivate students' good habit of explaining life phenomena with biological theory.

(4) Summarize the homework

This section has experienced the general process of scientific inquiry: asking questions, putting forward assumptions, designing experiments, conducting experiments, analyzing results, drawing conclusions, expressing communication and so on.

After writing the experimental report after class, I wondered: We know that water molecules enter and leave the cell along the relative content gradient. What about other molecules? For example, inorganic salts, how do they get in and out of cells? Please consult relevant materials after class, or design experiments to explore. Explore how other molecules such as inorganic salts enter and leave cells.

Seven, say blackboard writing design

Examples of transmembrane transport of substances

First, ask questions.

Second, make assumptions.

Third, design experiments (experimental ideas, experimental expectations, specific steps)

Fourth, conduct experiments.

Verb (abbreviation for verb) analyzes the results and draws a conclusion.

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