5A - CP10 Rate of photosynthesis

Question 1

What are the main external factors that affect the rate of photosynthesis?

Answer 1

Light intensity, carbon dioxide concentration, and temperature.

Question 2

What are these factors known as?

Answer 2

These factors are known as limiting factors of photosynthesis.

Question 3

Can photosynthesis occur at its maximum rate if any of the limiting factors are below the optimum level?

Answer 3

No, if any of the limiting factors are below the optimum level, the rate of photosynthesis will be reduced.

Question 4

Is water considered one of the main limiting factors for photosynthesis?

Answer 4

No, although a lack of water can reduce the rate of photosynthesis, water shortages usually affect other processes in the plant before affecting photosynthesis.

Question 5

How does light intensity affect the rate of photosynthesis?

Answer 5

The rate of photosynthesis increases as light intensity increases. Higher light intensity supplies more energy, allowing the light-dependent stage and the Calvin cycle to occur at a greater rate.

Question 6

What happens when light intensity continues to increase beyond a certain point?

Answer 6

At some point, if light intensity continues to increase, the rate of photosynthesis will reach a plateau, indicating that another factor is limiting the rate, such as temperature or carbon dioxide availability.

Question 7

How does carbon dioxide concentration affect the rate of photosynthesis?

Answer 7

The rate of photosynthesis increases as carbon dioxide concentration increases. More carbon dioxide enables faster carbon fixation during the light-independent stage, leading to an overall higher rate of photosynthesis.

Question 8

What is the relationship between carbon dioxide concentration and the rate of photosynthesis?

Answer 8

The relationship is positive, where an increase in carbon dioxide concentration results in an increase in the rate of photosynthesis, until another limiting factor prevents further rate increases.

Question 9

How does temperature affect the rate of photosynthesis?

Answer 9

The rate of photosynthesis increases up to an optimum temperature, beyond which the rate decreases. Enzyme-catalyzed reactions occur more slowly at low temperatures and enzymes denature at high temperatures.

Question 10

Which stage of photosynthesis is affected by temperature?

Answer 10

The light-independent stage, specifically the reactions involving the enzyme rubisco, is affected by temperature.

Question 11

How can the effects of light intensity, light wavelength, carbon dioxide concentration, and temperature on the rate of photosynthesis be investigated?

Answer 11

They can be investigated using aquatic plants such as Elodea or Cabomba and manipulating factors such as distance of light source, color filter, sodium hydrogen carbonate concentration, and water bath temperature.

Question 12

Why are aquatic plants useful for investigating the rate of photosynthesis?

Answer 12

Aquatic plants allow for the easy collection and measurement of waste oxygen gas produced during photosynthesis underwater.

Question 13

How can the effect of light intensity on the rate of photosynthesis be investigated?

Answer 13

By changing the distance of a light source from a plant and measuring the volume of oxygen produced over a set period of time.

Question 14

What is the purpose of using a glass tank between the lamp and the plant during the investigation of light intensity?

Answer 14

The glass tank absorbs heat from the lamp, preventing changes in temperature of the solution surrounding the plant, ensuring that only light intensity is the variable being investigated.

Question 15

What is chromatography used for in photosynthesis research?

Answer 15

Chromatography is used to separate and identify photosynthetic pigments, analyze their absorption spectra, and compare pigment variations under different conditions.

Question 16

How can chromatography be used to identify unknown pigments?

Answer 16

By comparing the Rf values of unknown pigments with those of known pigments, tentative identification of the unknown pigments can be made.

Question 17

What are the main components required for photosynthesis to occur?

Answer 17

The presence of photosynthetic pigments, a supply of carbon dioxide, a supply of water, light energy, and a suitable temperature.

Question 18

What are the main factors that affect the rate of photosynthesis?

Answer 18

Light intensity, carbon dioxide concentration, and temperature are the main factors that affect the rate of photosynthesis.

Question 19

What is the purpose of investigating the rate of photosynthesis?

Answer 19

Investigating the rate of photosynthesis helps understand the factors that influence the efficiency of this vital process and how plants respond to their environment.

Question 20

Why is it important to keep other factors constant during investigations of photosynthesis?

Answer 20

Keeping other factors constant ensures that any observed changes in the rate of photosynthesis can be attributed to the specific factor being investigated.

Question 21

What is the significance of the action spectrum in photosynthesis?

Answer 21

The action spectrum shows the effectiveness of different wavelengths of light in driving photosynthesis, reflecting the absorption spectra of various photosynthetic pigments.

Question 22

How does light wavelength affect the rate of photosynthesis?

Answer 22

Different photosynthetic pigments have different absorption spectra, so the rate of photosynthesis may vary depending on the wavelengths of light available.

Question 23

Can the rate of photosynthesis continue to increase indefinitely with optimal conditions?

Answer 23

No, even with optimal conditions, the rate of photosynthesis eventually reaches a point where other factors become limiting, such as temperature or carbon dioxide concentration.

Question 24

What are some adaptations that plants have developed to optimize photosynthesis?

Answer 24

Plants have various adaptations, such as leaf structures, specialized pigments, and mechanisms for water and nutrient uptake, to maximize their photosynthetic efficiency.

Question 25

How does the rate of photosynthesis impact the overall productivity and growth of plants?

Answer 25

The rate of photosynthesis directly affects the amount of energy and organic compounds that plants produce, which in turn supports their growth, development, and overall productivity.

Question 26

How does photosynthesis contribute to the oxygen levels in the atmosphere?

Answer 26

Photosynthesis is responsible for the production of oxygen as a byproduct, which is released into the atmosphere and plays a vital role in supporting aerobic life forms.

Question 27

Can photosynthesis occur in other organisms apart from plants?

Answer 27

Photosynthesis also occurs in other organisms such as algae and some bacteria, where similar processes and pigments are involved in converting light energy into chemical energy.

Question 28

What are the possible applications of studying photosynthesis?

Answer 28

What are the possible applications of studying photosynthesis?
A: Understanding photosynthesis has numerous applications, including improving crop production, developing sustainable energy sources, and mitigating the effects of climate change.

Question 29

How does the rate of photosynthesis vary with different plant species and environmental conditions?

Answer 29

Different plant species have different photosynthetic capacities and responses to environmental factors, allowing them to adapt and thrive in various ecosystems.

Question 30

How does the regulation of photosynthesis help plants maintain their energy balance?

Answer 30

Plants have mechanisms to regulate photosynthesis, adjusting the rate based on energy demands, environmental conditions, and the availability of resources like light, water, and carbon dioxide.