Do breathing and photosynthesis form in dark and light environments, respectively?

Photosynthesis is carried out in the presence of light. Whereas, light breathing is done throughout the day. Since photosynthesis is greater than respiration during the day, respiration is not significant.

Photorespiration is a biochemical process that occurs in all cells undergoing photosynthesis under the conditions of light and high oxygen and low carbon dioxide. It is a side reaction of photosynthesis that loses energy. Respiration of green plants under light conditions.

The characteristic is that although CO2 is also released during the decomposition and transformation of the respiratory matrix, it cannot be converted into energy ATP, so that the photosynthetic products are consumed in vain. Under dark conditions, the respiration process can be continuously converted into ATP, and free energy can be released for the absorption function of the root system, the synthesis and operation of organic substances, and the metabolic reaction of various substances, so as to promote the smooth progress of life activities. Therefore, the stronger the photorespiration, the lower the photosynthetic productivity.

According to the measurement of the atmospheric oxygen concentration at 21%, the photorespiration intensity of tea leaves is higher than that of ordinary plants.

Your statement is not true, photosynthesis can only take place when it is in light. Respiration takes place all the time as long as the cells are alive and has nothing to do with light.

No, living beings need to breathe as long as they are alive, and it has nothing to do with light, and the process of photosynthesis does not necessarily require light.

1. Photorespiration refers to the process by which green cells absorb O2 and release CO2 under light. This reaction requires chloroplasts to participate and occurs only in the presence of light at the same time as photosynthesis, and the photorespiration substrate glycolic acid is mainly provided by photosynthetic carbon metabolism.

The fundamental reason for the concomitant occurrence of photorespiration and photosynthesis is determined by the nature of Rubisco, which is a bifunctional enzyme that catalyzes both carboxylation and oxygenation, that is, the competition between CO2 and O2 Rubisco is the same active site and is an inhibitor of oxygenation and carboxylation reactions of each other. Therefore, in the atmosphere where O2 and CO2 coexist, photorespiration and photosynthesis occur at the same time, which both inhibit and promote each other, such as photosynthetic oxygen release can promote oxygenation reaction, and the CO2 released by photorespiration can be used as a substrate for light and interaction.

2. Physiological significance:

1) **Carbon source ** Glycolic acid can be oxidized by C2 carbon oxidation ring 3 4 carbon.

2) Maintain the operation of the C3 photosynthetic carbon reduction cycle When the leaf stomata are closed or the external CO2 concentration is low, the CO2 released by photorespiration can be reused by the C3 pathway to maintain the operation of the photosynthetic carbon reduction cycle.

3) Prevent the destructive effect of strong light on the photosynthetic mechanism Under strong light, the assimilation force formed in the light reaction will exceed the need for CO2 assimilation, so that the ratio of NADPH and ATP ADP in chloroplasts will be higher. At the same time, the high-energy electrons excited by light will be transferred to O2, and the superoxide anion radicals formed will have a harmful effect on the photosynthetic membrane, light and organs, while photorespiration can consume assimilation force and high-energy electrons, reduce the formation of superoxide anion radicals, and thus protect chloroplasts, so as to avoid or reduce the damage of strong light to the photosynthetic mechanism.

Respiration is divided into aerobic respiration and anaerobic respiration, and the reactants are mainly glucose

Changes in the substance of aerobic respiration Glucose produces pyruvate and H in the first stage, pyruvate and water produce carbon dioxide and H in the second phase, H and oxygen used produce water in the third phase, and energy is released in all three phases.

Anaerobic respiration changes in glucose, lactic acid, or alcohol and carbon dioxide.

Photosynthesis consists of two phases: light reaction and dark reaction

Photoreactive substances change the synthesis of water into H and oxygen, ATP.

The changes of dark reactive substances are as follows: carbon oxide is fixed by C5 to form C3, and C3 is reduced by H to form organic matter such as C5 and glucose.

Answer: Plants undergo photosynthesis and respiration at the same time, and the intensity of respiration is greater than the intensity of photosynthesis.

The carbon dioxide produced by plant respiration (denoted by m) is released into the surrounding environment (denoted by bending m2) except for photosynthesis (denoted by m1) used for plant respiration.

In addition to the oxygen used in plant respiration (denoted by n), the insufficient oxygen is absorbed from the outer boundary (denoted by n2) in addition to the photosynthesis of the plant itself (denoted by n1).

n＝n1+n2；m m1 m2 The external condition is that there is light, and the green plants placed in the closed container carry out photosynthesis and respiration at the same time, and the measured increase in O2, CO2 decrease or increase in organic matter can represent the net photosynthetic rate, and the real photosynthetic rate Net photosynthetic rate Respiration rate.

Net photosynthetic rate]:

The amount of CO2 uptake by the plant (leaf) or the reduction of CO2 in the experimental vessel was determined;

the amount of O2 released by the plant (leaf) or the increase in O2 "in the container";

The amount of "glucose accumulation or increase in plant (leaf) mass (organic matter") of the plant (leaf").

Total photosynthetic rate]:

the amount of CO2 "absorbed" by chloroplasts;

Assimilation of CO2;

The amount of O2 "released" by chloroplasts;

total O2 production;

the amount of glucose that plants or chloroplasts "produce";

The amount of organic matter produced by plants.

Respiration rate]: the amount of CO2 released by plants under dark conditions; O2 absorption; Organic matter consumption.

Because photorespiration is a side reaction of photosynthesis that loses energy.

Photosynthesis absorbs carbon dioxide to release oxygen, and photorespiration consumes oxygen to produce carbon dioxide, and photorespiration cancels out about 30% of photosynthesis.

Photorespiration is a reaction in which the green cells of plants absorb oxygen and release CO2 when exposed to light, which requires the participation of chloroplasts and occurs only in the presence of light at the same time as photosynthesis.

For A,1, only part of the [H] produced in the process enters the dark reaction to reduce CO2 and finally generate water, and a part is used for light and phosphorylation to synthesize ATP, which provides energy for the dark reaction. You can also think of it this way, if [h] all produce water, then there must be the same amount of water before and after the whole reaction, but in fact 12 go in and 6 come out.

b.3. The process described in 3 is glycolysis, which can be carried out by all cellular organisms.

c.The most energy released in the process of aerobic respiration is represented by 5, and the electron transport chain process process represents the dark reaction stage of photosynthesis, which requires a large number of enzymes to participate in the immobilization of CO2.

It is a process of photosynthesis, which produces [h] is the reducing power, which is used to synthesize organic matter, not water;

b。Process 3 is the process of glycolysis, which is the process of turning glucose into pyruvate, which does not require oxygen, and all cells have to carry out this process.

c。Process 5 is aerobic respiration! The most energy is released.

d。2 is a dark reaction in photosynthesis that converts the active chemical energy fixed by photosynthetic pigments into stable chemical energy (organic matter, glucose), this process is the fixation of CO2, also known as the Calvin cycle, which requires a variety of enzymes.

How do I feel that I should choose B, some bacteria can't decompose C6H12O6, they can only decompose nitrogen compounds, and the nitrogen cycle is mentioned in it.

The physiological activities of green plants include: photosynthesis, transpiration, respiration a, photosynthesis hall action, respiration and transpiration of plants under light, and respiration and transpiration in the dark

b. The absorption of inorganic salts by roots is a process of active transportation, so it consumes energy, so it does not conform to the topic c. The transpiration pull generated by transpiration promotes the absorption and transportation of water by plants, so it does not conform to the topic

d. When the stomata are opened, the water in the leaf absorbs heat and becomes water vapor, which diffuses into the outside air through the stomata Therefore, the stomata are the "gateway" for the transpiration and water loss of the plant body, and it is also the "window" for the gas exchange between the plant body and the outside world

Therefore, d

Photosynthesis: 12H2O6CO2 (via chloroplast, light) C6H12O6 (glucose) 6O2 6H2O

Respiration: Organic matter, oxygen (through mitochondria), carbon dioxide, water, energy.

Light Reaction:

Conditions: Light, photosynthetic pigments, photoreactive enzymes.

Location: thylakoid membranes of chloroplasts. (pigments).

Light of water2H2O4[H]+O2 (catalyzed by light and pigments in chloroplasts).Synthesis of ATP: ADP + PI ATP (catalyzed by light, enzymes and chloroplasts in pigments).

Influencing factors: light intensity, CO2 concentration, water supply, temperature, pH, etc.

Significance: Photolysis of water, production of oxygen. Converts light energy into chemical energy to produce ATP, which provides energy for dark reactions. Using hydrogen ions, the product of water photolysis, Nadph is synthesized to provide a reducing agent Nadph. for dark reactions

Dark reactions (essentially a series of enzymatic reactions).

Conditions: Dark Reactive Enzymes.

Location: Chloroplast matrix.

Influencing factors: temperature, CO2 concentration, pH, etc.

Different plants have different processes of dark reactions, and the anatomy of the leaves is also different. This is the result of the plant's adaptation to the environment. Dark reactions can be divided into three types: C3, C4, and CAM.

The three types are divided according to the process of carbon dioxide fixation. For the most common type of C3 reaction, plants inhale CO2 from the outside into the cell through the stomata and into the chloroplast through free diffusion. Chloroplasts contain C5

It plays a role in fixing CO2 into C3. C3 then reacts with the energy provided by Nadph and ATP to form carbohydrates (CH2O) and reduce C5The restored C5 continues to participate in the dark reaction.

The essence of photosynthesis is the conversion of CO2 and H2O into organic matter (change of matter) and the conversion of light energy into active chemical energy in ATP and then into stable chemical energy in organic matter (energy change).

CO2 + H2O (chloroplast, enzyme, light) *****==O2+(C6H10O5)N

Plant respiration process: organic matter + oxygen (through mitochondria) carbon dioxide + water + energy.

Chemical Formula: Organic matter (generally glucose C6H12O6) + O2 (condition: enzyme) CO2 + H2O+ energy. Or: C6H12O6 6O2 6CO2 6H2O 2821kJ

The process by which plants oxidize organic compounds under aerobic conditions to produce CO2 and water.

The energy produced in this process can be partially used for various life activities. When plant tissues are undersupplied with oxygen or no oxygen, the organic matter in them can partially decompose, producing a small amount of CO2 and releasing a small amount of energy. This is fermentation, sometimes referred to as anaerobic respiration.

In contrast, respiration when oxygen is sufficient** is also known as aerobic respiration. The green part of the three-carbon plant continues to oxidize under light with glycolic acid, the oxidation product of ribulose diphosphate, as substrate, to produce CO2

Photosynthesis is the absorption of carbon dioxide by plants, the release of oxygen, and occurs during the day (with sunlight).

Respiration, in which plants absorb oxygen and release carbon dioxide, occurs at night (without sunlight).