"Elements and Compounds in Cells" PPT teaching courseware on the molecules that make up cells

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"Elements and Compounds in Cells" PPT teaching courseware on the molecules that make up cells

Part 1: Essential knowledge and foundation of literacy

1. Elements that make up cells

1. Unity and difference of elements:

2. Types of elements:

(2) The most abundant element in cells: ___________, the reason is related to _______________.

【Doubtful】

Fe is a trace element. Is it dispensable in living organisms? Tell us your reasons.

Hint: No. The content of trace elements in living organisms is very small, but their physiological functions are very important. For example, Fe is an important component of human hemoglobin. Fe deficiency can lead to iron deficiency anemia.

2. Compounds that make up cells

Please judge whether the following statements are correct or incorrect based on the types and contents of the compounds that make up cells:

1. All the elements that make up cells exist in the form of compounds. ( )

Tip: Most of the elements that make up cells exist in the form of compounds, and some can exist in the form of ions, such as K+.

2. Water and inorganic salts are inorganic compounds that make up cells, including sugars, lipids,

Proteins and nucleic acids are the organic compounds that make up cells. ( )

3. The most abundant compound in living cells of the human body is water. ( )

4. The compounds that account for the largest amount of cell dry weight are lipids. ( )

Tip: Protein is the compound that accounts for the largest amount of cell dry weight.

5. The organic compound that accounts for the most fresh weight of cells is protein. ( )

6. The compound content is the same in all cells. ( )

Tip: The content of compounds in different cells is different, such as in wheat seed cells

The sugar content is higher, while the fat content in peanut seed cells is higher.

3. Detection of carbohydrates, fats and proteins in biological tissues

1. Experimental principle (connection):

2. Experimental procedures and conclusions:

(1) Detection of reducing sugars.

(2) Fat detection.

(3) Detection of protein.

Elements and Compounds in Cells PPT, Part 2: Key Abilities·Quality Formation

Knowledge point 1: Elements and compounds that make up cells

1. Types and contents of elements that make up cells:

(1) The classification of macroelements and trace elements is based on the content of the elements in cells, rather than the size of their physiological effects.

(2) Regardless of dry weight or fresh weight, the four elements C, H, O and N are the most abundant in cells.

2. The types and contents of nutrients in different foods are different:

(1) Corn seeds, sugarcane stems, beet roots, and apples: are rich in sugar.

(2) Peanut seeds: rich in fat.

(3) Milk, eggs, soybean seeds: rich in protein.

【Think·Discussion】

In nutrition, judging whether an element is necessary for the human body is not based on whether the element appears in the body's composition, but on whether the element is essential for human health. Do you think this statement is reasonable? Give your reasons. (Scientific thinking, social responsibility)

Tip: Reasonable. Some elements appear in the composition of the human body, but are not necessary for the human body and may even be harmful to human health, such as lead (Pb).

【Literacy Case】

According to the diagram analysis, the following statement is correct ()

A. If this picture represents the content of each chemical element in the cell, then A should be carbon.

B. If the picture represents the content of each chemical element in animal or plant cells, then A represents the same type of element.

C. If this picture shows the composition of compounds in cells, then the elements contained in A are C, H, and O

D. If the picture shows the composition of compounds in cells that have been completely dehydrated, then A is a protein.

Knowledge Point 2: Detecting organic matter in biological tissues

1. Comparison between Fehling's reagent and biuret reagent:

2. Experimental notes:

(1) Points of attention during experimental operations.

① When testing reducing sugar, use a water bath for heating, and do not touch the bottom of the test tube to the bottom of the beaker to prevent uneven heating.

② When detecting fat, the staining time should not be too long, otherwise the fat will dissolve in the alcohol and the orange color will disappear.

③When detecting protein, the order of adding biuret reagent: add solution A first, then add solution B, and solution B cannot be excessive. The purpose is to create an alkaline environment first. If liquid B is added first or if liquid B is excessive, Cu(OH)2 will be generated and interfere with the color reaction.

④In the protein detection experiment, the egg white needs to be diluted to a certain extent, otherwise after reacting with the biuret reagent, it will stick to the inner wall of the test tube, the reaction will not be complete, and the test tube will not be easy to clean.

⑤ In the detection experiment of reducing sugar and protein, before adding the corresponding reagents for detection, a part of the tissue sample liquid should be set aside to compare with the color of the sample liquid after detection.

(2) Differences in operating procedures for organic matter detection.

①Heating - The detection of reducing sugar requires heating, and it is heated in a water bath.

②Microscope - If you use peanut seed slices as material to detect fat, you need to use a microscope.

③The order of adding reagents - first mix equal amounts and then add dropwise Fehling's reagent, and add biuret reagent separately.

【Think·Discussion】

A classmate designed the following experimental plan:

Add an appropriate amount of tomato homogenate to the test tube, then add the newly prepared Fehling's reagent, and heat in a water bath. Try to analyze whether the experimental design is reasonable. If not, please correct it. (scientific thinking, scientific inquiry)

Tip: Unreasonable. Tomatoes should be replaced with colorless or nearly colorless materials such as pear homogenate, because tomato homogenate is red and will interfere with the experimental results.

Keywords: Free download of the PPT courseware for high school biology compulsory course 1 from the People's Education Press, PPT download of elements and compounds in cells, PPT download of molecules that make up cells, .PPT format;

For more information about the PPT courseware "Molecules Composing Cells Elements and Compounds in Cells", please click the Molecules Composing Cells ppt Elements and Compounds in Cells ppt tag.

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Update Time: 2024-10-04

This template belongs to biology courseware High School Biology Compulsory Course 1, published by People's Education Press industry PPT template

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