Podcast
Questions and Answers
What structure in carboxysomes helps resist CO2 efflux?
What structure in carboxysomes helps resist CO2 efflux?
Which transporter is present in thylakoids that facilitates the uptake of inorganic carbon?
Which transporter is present in thylakoids that facilitates the uptake of inorganic carbon?
What is the role of Rubisco in carboxysomes?
What is the role of Rubisco in carboxysomes?
What type of molecular structure does the carboxysome have?
What type of molecular structure does the carboxysome have?
Signup and view all the answers
What primary function do transporters for CO2 serve in cyanobacteria?
What primary function do transporters for CO2 serve in cyanobacteria?
Signup and view all the answers
In the C4 cycle proposed by Hatch and Slack, which compound accumulates first after the incorporation of 14CO2?
In the C4 cycle proposed by Hatch and Slack, which compound accumulates first after the incorporation of 14CO2?
Signup and view all the answers
What is the main role of the compounds that accumulate during the C4 cycle?
What is the main role of the compounds that accumulate during the C4 cycle?
Signup and view all the answers
Which of the following is directly associated with the Rubisco-catalyzed reaction in the context of the C4 cycle?
Which of the following is directly associated with the Rubisco-catalyzed reaction in the context of the C4 cycle?
Signup and view all the answers
What cellular process is primarily affected by the accumulation of 3-PGA in the outlined cycle?
What cellular process is primarily affected by the accumulation of 3-PGA in the outlined cycle?
Signup and view all the answers
Which component is essential for the initial carboxylation reaction in the C4 cycle?
Which component is essential for the initial carboxylation reaction in the C4 cycle?
Signup and view all the answers
What role does carbonic anhydrase (CA) play in the chloroplast?
What role does carbonic anhydrase (CA) play in the chloroplast?
Signup and view all the answers
What is the first product accumulated during the carboxylation reaction described by Hatch and Slack in 1966?
What is the first product accumulated during the carboxylation reaction described by Hatch and Slack in 1966?
Signup and view all the answers
Why is back-diffusion of CO2 slowed in the pyrenoid?
Why is back-diffusion of CO2 slowed in the pyrenoid?
Signup and view all the answers
In the study by Engel et al. (2015), what technique was used to reveal the native architecture of the Chlamydomonas chloroplast?
In the study by Engel et al. (2015), what technique was used to reveal the native architecture of the Chlamydomonas chloroplast?
Signup and view all the answers
Which statement about HCO3- transport is correct?
Which statement about HCO3- transport is correct?
Signup and view all the answers
Which compound is labeled first during a pulse-chase study with 14CO2 according to the findings by Hatch and Slack?
Which compound is labeled first during a pulse-chase study with 14CO2 according to the findings by Hatch and Slack?
Signup and view all the answers
What is the permeability of the CO2 molecule across the membrane?
What is the permeability of the CO2 molecule across the membrane?
Signup and view all the answers
Which of the following statements is NOT true regarding the carbon fixation machinery as discussed in the referenced studies?
Which of the following statements is NOT true regarding the carbon fixation machinery as discussed in the referenced studies?
Signup and view all the answers
What does the starch layer in the pyrenoid do?
What does the starch layer in the pyrenoid do?
Signup and view all the answers
What did the study by Liu (2016) focus on in cyanobacteria?
What did the study by Liu (2016) focus on in cyanobacteria?
Signup and view all the answers
How does CO2 concentration occur in the pyrenoids?
How does CO2 concentration occur in the pyrenoids?
Signup and view all the answers
Which of the following acids does the 14CO2 label accumulate in first during Hatch and Slack's carboxylation reaction?
Which of the following acids does the 14CO2 label accumulate in first during Hatch and Slack's carboxylation reaction?
Signup and view all the answers
What impact does HCO3- have on CO2 availability in chloroplasts?
What impact does HCO3- have on CO2 availability in chloroplasts?
Signup and view all the answers
What type of study did Hatch and Slack conduct to explore the carboxylation reaction?
What type of study did Hatch and Slack conduct to explore the carboxylation reaction?
Signup and view all the answers
Which of the following was NOT mentioned as a product or intermediate in the carbon fixation studies referenced?
Which of the following was NOT mentioned as a product or intermediate in the carbon fixation studies referenced?
Signup and view all the answers
What is the relationship between Rubisco and pyrenoids?
What is the relationship between Rubisco and pyrenoids?
Signup and view all the answers
What type of membrane is permeable to CO2?
What type of membrane is permeable to CO2?
Signup and view all the answers
What is the main function of transporters in the pyrenoid?
What is the main function of transporters in the pyrenoid?
Signup and view all the answers
At what temperatures do C3 plants have an advantage over C4 plants?
At what temperatures do C3 plants have an advantage over C4 plants?
Signup and view all the answers
What is a significant energy requirement for C4 photosynthesis?
What is a significant energy requirement for C4 photosynthesis?
Signup and view all the answers
What happens to photorespiration as temperature increases?
What happens to photorespiration as temperature increases?
Signup and view all the answers
Why hasn’t C4 photosynthesis evolved in all environments?
Why hasn’t C4 photosynthesis evolved in all environments?
Signup and view all the answers
Which statement accurately describes the relationship between C4 plants and temperature?
Which statement accurately describes the relationship between C4 plants and temperature?
Signup and view all the answers
Study Notes
Cyanobacteria Carbon Fixation
- Cyanobacteria use carboxysomes to concentrate carbon dioxide
- Carboxysomes are icosahedral protein shells with Rubisco packed inside
- Carboxysomes resist carbon dioxide efflux
- Cyanobacteria use bicarbonate transporters to bring inorganic carbon into the cell
Pyrenoids
- Pyrenoids are organelles used by cyanobacteria and algae for CO2 fixation
- Pyrenoids concentrate CO2 via transporters and carbonic anhydrase
- Pyrenoids are surrounded by a starch layer which is impermeable to CO2 and HCO3-
- CO2 is permeable across the plasma membrane
- Pyrenoids have specific transporters to move HCO3- through the chloroplast envelope and thylakoids
C4 Photosynthesis
- C4 photosynthesis was discovered by Hatch and Slack in 1966. They used pulse-chase experiments with 14C labeled CO2
- C4 photosynthesis involves a new carboxylation reaction
- The first product of C4 photosynthesis to be labeled was malate and other C4 acids, then 3-PGA
- The core of the C4 cycle was proposed by Hatch and Slack in 1966
C4 vs. C3 Photosynthesis
- C3 photosynthesis is favored at cooler temperatures
- C4 photosynthesis requires more energy
- C4 photosynthesis is favored at high temperatures
- The main advantage of C3 photosynthesis is that it is less costly in terms of energy use
- Photorespiration increases as temperature increases for C3 plants
- C4 plants are favored at high temperatures due to lower levels of photorespiration
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the fascinating mechanisms of carbon fixation in cyanobacteria and C4 plants. This quiz covers topics such as carboxysomes, pyrenoids, and the discoveries made by Hatch and Slack in 1966. Test your knowledge on how these organisms concentrate carbon dioxide for photosynthesis.
