Textbook Question
At what point in photosynthesis is the electromagnetic energy of light first converted into chemical energy?
3
views
Ch. 10 - Photosynthesis
Freeman8th EditionBiological ScienceISBN: 9780138276263
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 - Biology: The Study of Life13
- Ch. 2 - Water and Carbon: The Chemical Basis of Life14
- Ch.3 - Protein Structure and Function10
- Ch.4 - Nucleic Acids and the RNA World10
- Ch. 5 - An Introduction to Carbohydrates10
- Ch. 6 - Lipids, Membranes, and the First Cells11
- Ch. 7 - Inside the Cell10
- Ch. 8 - Energy and Enzymes: An Introduction to Metabolism10
- Ch. 9 - Cellular Respiration and Fermentation11
- Ch. 10 - Photosynthesis12
- Ch. 11 - Cell-Cell Interactions12
- Ch. 12 - The Cell Cycle8
- Ch. 13 - Meiosis12
- Ch. 14 - Mendel and the Gene23
- Ch. 15 - DNA and the Gene: Synthesis and Repair15
- Ch. 16 - How Genes Work16
- Ch. 17 - Transcription, RNA Processing, and Translation16
- Ch. 18 - Control of Gene Expression in Bacteria16
- Ch. 19 - Control of Gene Expression in Eukaryotes12
- Ch. 20 - The Molecular Revolution: Biotechnology, Genomics, and New Frontiers15
- Ch. 21 - Genes, Development, and Evolution12
- Ch. 22 - Evolution by Natural Selection16
- Ch. 23 - Evolutionary Processes13
- Ch. 24 - Speciation15
- Ch. 25 - Phylogenies and the History of Life13
- Ch. 26 - Bacteria and Archaea15
- Ch. 27 - Diversification of Eukaryotes16
- Ch. 28 - Green Algae and Land Plants16
- Ch. 29 - Fungi18
- Ch. 30 - An Introduction to Animals9
- Ch. 31 - Protostome Animals15
- Ch. 32 - Deuterostome Animals17
- Ch. 33 - Viruses16
- Ch. 34 - Plant Form and Function16
- Ch. 35 - Water and Sugar Transport in Plants16
- Ch. 36 - Plant Nutrition13
- Ch. 37 - Plant Sensory Systems, Signals, and Responses16
- Ch. 38 - Flowering Plant Reproduction and Development16
- Ch. 39 - Animal Form and Function17
- Ch. 40 - Water and Electrolyte Balance in Animals16
- Ch. 41 - Animal Nutrition16
- Ch. 42 - Gas Exchange and Circulation16
- Ch. 43 - Animal Nervous Systems16
- Ch. 44 - Animal Sensory Systems16
- Ch. 45 - Animal Movement11
- Ch. 46 - Chemical Signals in Animals16
- Ch. 47 - Animal Reproduction and Development16
- Ch. 48 - The Immune System in Animals16
- Ch. 49 - An Introduction to Ecology15
- Ch. 50 - Behavioral Ecology16
- Ch. 51 - Population Ecology16
- Ch. 52 - Community Ecology20
- Ch. 53 - Ecosystems and Global Ecology17
- Ch. 54 - Biodiversity and Conservation Ecology18
Chapter 10, Problem 3
What is the role of PEP carboxylase in C4 and CAM plants?
a. It fixes CO2 into an organic acid.
b. It produces ATP for the Calvin cycle.
c. It replaces rubicso in the Calvin cycle.
d. It releases CO2 from organic acids.
Verified step by step guidance1
Understand the context: C4 and CAM plants have adapted to hot and dry environments by modifying their photosynthetic processes to minimize water loss and photorespiration.
Identify the role of PEP carboxylase: In both C4 and CAM plants, PEP carboxylase is an enzyme that plays a crucial role in the initial steps of carbon fixation.
Explain the function of PEP carboxylase: This enzyme catalyzes the addition of CO2 to phosphoenolpyruvate (PEP) to form oxaloacetate, a four-carbon compound, which is then converted into malate or other organic acids.
Clarify the significance: By fixing CO2 into organic acids, PEP carboxylase helps concentrate CO2 around the enzyme Rubisco, reducing photorespiration and increasing the efficiency of photosynthesis.
Conclude with the correct option: Based on the role of PEP carboxylase, the correct answer is option a: It fixes CO2 into an organic acid.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
4mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
PEP Carboxylase
PEP carboxylase is an enzyme that catalyzes the fixation of carbon dioxide (CO2) into a four-carbon compound, oxaloacetate, in C4 and CAM plants. This process occurs in the mesophyll cells and is crucial for capturing CO2 efficiently, especially under conditions where rubisco is less effective, such as high oxygen concentrations or low CO2 levels.
C4 Photosynthesis
C4 photosynthesis is a pathway that some plants use to efficiently fix CO2 in hot and dry environments. It involves the initial fixation of CO2 by PEP carboxylase into a four-carbon compound, which is then transported to bundle-sheath cells where CO2 is released for use in the Calvin cycle. This mechanism minimizes photorespiration and increases water-use efficiency.
Recommended video:
Guided course
04:34
C3, C4 & CAM Plants
CAM Photosynthesis
CAM (Crassulacean Acid Metabolism) photosynthesis is an adaptation in some plants to arid conditions, allowing them to fix CO2 at night when stomata are open. PEP carboxylase fixes CO2 into organic acids, which are stored in vacuoles. During the day, CO2 is released from these acids for use in the Calvin cycle, reducing water loss by keeping stomata closed during the hottest part of the day.
Recommended video:
Guided course
04:34C3, C4 & CAM Plants
Related Practice
Textbook Question
Why is chlorophyll green?
a. It absorbs all wavelengths in the visible spectrum.
b. It absorbs wavelengths only in the red portions of the spectrum (680–700 nm).
c. It absorbs wavelengths only in the blue part of the visible spectrum (450–480 nm).
d. It absorbs wavelengths in only the blue and red parts of the visible spectrum.
Textbook Question
How is energy transferred among antenna pigment molecules?
a. By heat
b. By redox reactions
c. By fluorescence
d. By resonance
Textbook Question
Why is the chlorophyll in chloroplasts less likely to produce fluorescence compared to extracted chlorophyll molecules?
Textbook Question
Describe the three phases of the Calvin cycle and how the products of the light-capturing reactions participate in this process.