Learning needs to pay attention to methods and skills, but also learn to summarize and sort out knowledge points. What are the knowledge points of Biology Elective 1 in Senior Two? The following is the 1 knowledge point of biology elective course in Grade Two, which I compiled for you. I hope it will help you! Summary of knowledge points of biology elective 1 in senior two

Fruit wine and fruit vinegar and production

1. Fruit wine production

1. Principle: strain belongs to nuclear organism, with metabolic type. When it is aerobic, the reaction formula of breathing is: When there is no oxygen, the reaction formula of breathing is:

2. conditions: the optimum temperature for reproduction, and alcohol fermentation is generally controlled at.

(source of yeast used in traditional fermentation technology)

3. Source of strain:

Now fruit wine is produced in factory. In order to improve the quality of fruit wine and better inhibit the growth of other microorganisms, the measures taken are as follows.

4. Flow chart of experimental design

Selecting grapes for washing _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Fruit wine and vinegar <

the function of inflation port; Exhaust port function;

the function of the discharge port.

the exhaust port should be connected with the bottle body through a long and curved hose, and its purpose is.

when using this device to make wine, it should be closed;

when making vinegar, the aerator should be installed.

6. analysis and evaluation of experimental results: it can be preliminarily identified by smell and taste, and the existence of alcohol can be tested by _ _ _ _ _ _ _ _ _ _. Observable phenomena are

2. Production of fruit vinegar:

1. Principle: strain: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

2. conditions: the most suitable temperature is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

3. strain source: purchase from _ _ _ _ _ _ _ _ _ or _ _ _ _ _ _ _ _.

4. Design the experimental flow and operation steps:

After the fruit wine is made, add _ _ _ _ _ _ _ _ _ _ _ _ _ or vinegar koji into the fermentation broth, and then transfer the device to _ _ _ _ _ _ _ _ _ _ _ C for fermentation, and add _ _ into the fermentation broth at the right time. If there is no inflator, you can open the bottle cap and put gauze on the bottle cap to reduce dust pollution in the air.

Third, the problems that should be paid attention to in the operation process

(1) In order to prevent the fermentation broth from being polluted, the fermentation bottle should be disinfected.

(2) When the grape juice is put into the fermentation bottle, you should leave an approximate space.

(3) When making wine, the temperature should be strictly controlled at, and the time should be controlled at about d, and the fermentation situation can be monitored in time.

(4) In the process of making grape vinegar, the temperature should be strictly controlled at, the time should be controlled at D, and the air should be inflated at the right time.

difficult points

1. Do you think the grapes should be washed or the branches should be removed first? Why?

The grapes should be washed first, and then the branches should be removed, so as to avoid grape damage caused by removing the branches and increase the chance of being contaminated by miscellaneous bacteria.

2. What do you think should be done to prevent the fermentation broth from being polluted?

It needs to be considered comprehensively from the fermentation process, because every step of the operation may be mixed with miscellaneous bacteria. For example, the juicer and fermentation device should be cleaned; Just unscrew the bottle cap and don't completely uncover the bottle cap every time you exhaust.

3. why should the temperature be controlled at 18 ~ 25℃ when making wine? When making grape vinegar, why should the temperature be controlled at 3 ~ 35℃?

a: temperature is an important condition for yeast growth and fermentation. About 2℃ is most suitable for yeast propagation. Therefore, it is necessary to control the temperature within its optimum temperature range. Acetobacter is psychrophiles, and the optimum growth temperature is 3 ~ 35℃, so the temperature should be controlled at 3 ~ 35℃.

4. When making grape vinegar, why should it be inflated through the inflation port at the right time?

a: Acetobacter is an aerobic bacterium, and oxygen is needed to change alcohol into acetic acid, so it is necessary to aerate the fermentation broth in time.

the making of sufu

1. the principle of making sufu

1. the fermentation of sufu has the synergistic effect of many microorganisms, such as,,,

, etc., among which the main function is. It is a kind of filiform, which is common in,, and. Metabolic type is.

2. Proteases produced by other microorganisms can decompose tofu into the sum of small molecules; Lipase can hydrolyze into and.

3. The modern production of sufu is to directly inoculate excellent strains on tofu under strict conditions, which can be avoided and guaranteed.

Second, the experimental process of making sufu:

Let tofu grow Mucor & rarr; & rarr; & rarr; Sealed and pickled.

Third, experimental materials

Tofu, zongzi leaves, plates, salt, yellow wine, rice wine, sugar, spices, etc. with a water content of 7%, wide-mouth glass bottles and pressure cookers.

Fourth, experimental steps

1. Make tofu 3 cm&; times; 3cm& times; 1cm pieces

2. Tofu pieces are placed in a dish covered with dried zongzi leaves, and each piece of tofu is equally spaced. Then clean zongzi leaves are laid on the tofu, and then wrapped with plastic wrap.

3. Put the flat plate at the temperature of , Mucor will grow gradually, and after about 5 days, the surface of tofu will be clustered with upright hyphae.

4. When Mucor grows vigorously and turns pale yellow, remove the plastic wrap and zongzi leaves to dissipate heat and moisture, and at the same time disperse the musty smell for about 36h.

5. After the tofu is completely cooled, pull off the hyphae between the tofu and arrange them neatly in a container for pickling.

6. Tofu blocks covered with Mucor (hereinafter referred to as blanks) are placed in layers, salted in layers, and increased with the height of the layer. Salt is spread on the surface of the bottle mouth to prevent it, and it will be cured for about 8 days.

7. Mix yellow rice wine, rice wine, sugar, spices, etc. to make bittern soup. It is appropriate to control the alcohol content of brine soup at.

8. Clean the wide-mouth glass bottle, steam sterilize it in an autoclave at 1C for 3min, put the fermented bean curd into a blank in the bottle, add the marinated soup and accessories, heat and sterilize the bottle mouth with an alcohol lamp, seal it with a rubber strip, and it will mature in six months at room temperature.

difficult points

1. why did Wang Zhihe sprinkle a lot of salt to pickle the hairy tofu? What role does salt play in this process?

Salt can prevent the contamination of miscellaneous bacteria and prevent tofu from spoilage. Salt can inhibit the growth of many microorganisms.

2. When preparing marinated soup, the alcohol content is generally controlled at about 12%, and it is not acceptable to be too high or too low. Why?

the alcohol content has a great relationship with the fermentation time in the later period of sufu. The higher the alcohol content, the greater the inhibitory effect on protease, which prolonged the maturity of sufu. If the alcohol content is too low, the activity of protease is high, which will accelerate the hydrolysis of protein, and the mixed bacteria will multiply quickly. Tofu is easy to rot and difficult to block.

3. What's the function of curing bean curd with salt?

① Permeate salt and separate out water; ② Give sufu the necessary salty taste; ③ Prevent Mucor from continuing to grow and polluted miscellaneous bacteria from multiplying; ④ Extract protease from Mucor silk;

4. What is the purpose of adding a large amount of wine to sufu in the later fermentation?

① prevent contamination by miscellaneous bacteria for preservation

② combine with organic acids to form esters. Because wine, especially yellow rice wine, contains yeast tapioca, alcohol can be produced by fermentation, which can be combined with organic acids to form esters, giving sufu flavor

③ facilitating later fermentation

5. What is the function of spices in marinated soup?

① seasoning ② promoting fermentation ③ sterilization and antisepsis

Explanation: (Spices such as pepper, garlic and fennel contain piperamide, allicin, anisole and anisaldehyde, which have strong bactericidal power; But also has good seasoning function; Spice ingredients participate in the fermentation process, and complex esters are synthesized, which makes sufu form special color, fragrance and taste. )

6. Can you use the biological knowledge you have learned to explain why tofu has long white hair?

a: the white hairs growing on tofu are white hyphae of Mucor. Strictly speaking, it is upright hyphae, and there are creeping hyphae in tofu.

7. Which tofu we usually eat is suitable for making sufu?

A: Tofu with a water content of about 7% is suitable for sufu. It is not easy to form sufu with tofu with too high water content.

8. When eating sufu, you will find a dense "skin" on the outside of sufu. How is this "skin" formed? Is it harmful to human body? What is its function?

Answer: "Skin" is the hypha (creeping hypha) that grows on the surface of tofu in the early stage of fermentation, and it can form the "body" of sufu, thus shaping it. Skin is harmless to human body.