which of the following molecules will accumulate if light reactions occur normally, but the calvin cycle is inhibited?
James
Guys, does anyone know the answer?
get which of the following molecules will accumulate if light reactions occur normally, but the calvin cycle is inhibited? from EN Bilgi.
Biology 1 (Biology 1610) CH.10
Start studying Biology 1 (Biology 1610) CH.10 - "Photosynthesis.". Learn vocabulary, terms, and more with flashcards, games, and other study tools.
Biology 1 (Biology 1610) CH.10 - "Photosynthesis."
77 studiers in the last day
_________________ are unable to make their own food; they live on compounds produced by other organisms. ________________ sustain themselves without eating anything derived from other living beings.
Click card to see definition 👆
Heterotrophs (Consumer)
Autotrophs (Producer)
Click again to see term 👆
Some heterotrophs consume the remains of other organisms and organic litter such as feces, and fallen leaves; these types of heterotrophs are known as _________________. Most fungi and many types of prokaryotes get their nourishment this way.
Click card to see definition 👆
decomposers
Click again to see term 👆
1/31 Created by Doworkson32PLUS
Terms in this set (31)
_________________ are unable to make their own food; they live on compounds produced by other organisms. ________________ sustain themselves without eating anything derived from other living beings.
Heterotrophs (Consumer)
Autotrophs (Producer)
Some heterotrophs consume the remains of other organisms and organic litter such as feces, and fallen leaves; these types of heterotrophs are known as _________________. Most fungi and many types of prokaryotes get their nourishment this way.
decomposers
Two metabolic processes occur in plant cells, what are they?
1. Photosynthesis
2. Cellular respiration
During photosynthesis what is reduced and what is oxidized?
Explain/Teach the two processes/stages of photosynthesis:
1. Light reactions 2. Calvin cycle
Which of the following processes is most directly driven by light energy?
A. carbon fixation in the stroma
B. reduction of NADP+ molecules
C. creation of a pH gradient by pumping protons across the thylakoid membrane
D. oxidation of chlorophyll molecules
D
Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. Which of the following statements best describes a related function they serve in plants?
A. They serve as accessory pigments to increase light absorption.
B. They protect against oxidative damage from excessive light energy.
C. They shield the sensitive chromosomes of the plant from harmful ultraviolet radiation.
D. They reflect orange light and enhance red light absorption by chlorophyll.
B
Which of these equations best summarizes photosynthesis?
A. 6 CO2 + 6 H2O → C6H12O6 + 6 O2
B. 6 CO2 + 6 O2 → C6H12O6 + 6 H2O
C. C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy
D. H2O → 2 H+ + 1/2 O2 + 2e-
E. C6H12O6 + 6 O2 → 6 CO2 + 12 H2O
A
Where does the Calvin cycle occur?
Stroma of the chloroplast in a mesophyll cell
The light reactions of photosynthesis use _____ and produce _____.
A. water ... NADPH B. NADPH ... NADP+ C. NADPH ... oxygen
D. carbon dioxide ... sugar
E. carbon dioxide ... oxygen
A
Sign up and see the remaining cards. It’s free!
Boost your grades with unlimited access to millions of flashcards, games and more.
Continue with Google
Continue with Facebook
Already have an account?
Recommended textbook explanations
Campbell Biology 11th Edition
Lisa A. Urry, Michael L. Cain, Peter V Minorsky, Steven A. Wasserman
1,679 explanations
Essentials Of Human Anatomy Physiology Books A La Carte Plus Mastering A P With Pearson Etext -- Access Card Package ( Edition)
12th Edition
Elaine Nicpon Marieb, Suzanne M. Keller
642 explanations
Connect 1-Semester Online Access for Concepts in Biology
14th Edition
Eldon D. Enger, Frederick C. Ross
934 explanations
Elevate Middle Grade Science 2019 Physical Student Edition Digital Couseware 4 Year
Prentice Hall 403 explanations
Sets with similar terms
Chapter 10
53 terms lasernapaige
Chapter 8 Life 120
71 terms dmorrell6
Photosynthesis coursenotes multiple choice
81 terms kimadele
Sets found in the same folder
Biology Chapter 10
65 terms TestQueen3
Mastering Chapter 8: Intro to Metabolism
79 terms ellielauren88PLUS
Mastering Biology Chapter 2 Practice Test
36 terms zoetaylor0525
Biology 1 (Biology 1610) CH.13 - "Meiosi…
14 terms Doworkson32PLUS
Other sets by this creator
Biology 1620 (EXAM 3)
36 terms Doworkson32PLUS
MCAT Question(s) of the Day
5 terms Doworkson32PLUS
HEP 3200 - Exam 2 (CH. 8, 14, 10, 22, 11, 13)
64 terms Doworkson32PLUS
Biology 1620 - CH. 50: Sensory Systems
17 terms Doworkson32PLUS
Verified questions
BIOLOGY
With respect to energy, how are ATP and glucose similar? How are they different?
5.3: The Calvin Cycle – Concepts of Biology – 1st Canadian Edition
5.3: THE CALVIN CYCLE
Learning Objectives
By the end of this section, you will be able to:
Describe the Calvin cycle
Define carbon fixation
Explain how photosynthesis works in the energy cycle of all living organisms
After the energy from the sun is converted and packaged into ATP and NADPH, the cell has the fuel needed to build food in the form of carbohydrate molecules. The carbohydrate molecules made will have a backbone of carbon atoms. Where does the carbon come from? The carbon atoms used to build carbohydrate molecules comes from carbon dioxide, the gas that animals exhale with each breath. The Calvin cycle is the term used for the reactions of photosynthesis that use the energy stored by the light-dependent reactions to form glucose and other carbohydrate molecules.
THE INTERWORKINGS OF THE CALVIN CYCLE
In plants, carbon dioxide (CO2) enters the chloroplast through the stomata and diffuses into the stroma of the chloroplast—the site of the Calvin cycle reactions where sugar is synthesized. The reactions are named after the scientist who discovered them, and reference the fact that the reactions function as a cycle. Others call it the Calvin-Benson cycle to include the name of another scientist involved in its discovery (Figure 5.14).
Figure 5.14 Light-dependent reactions harness energy from the sun to produce ATP and NADPH. These energy-carrying molecules travel into the stroma where the Calvin cycle reactions take place.
The Calvin cycle reactions (Figure 5.15) can be organized into three basic stages: fixation, reduction, and regeneration. In the stroma, in addition to CO2, two other chemicals are present to initiate the Calvin cycle: an enzyme abbreviated RuBisCO, and the molecule ribulose bisphosphate (RuBP). RuBP has five atoms of carbon and a phosphate group on each end.
RuBisCO catalyzes a reaction between CO2 and RuBP, which forms a six-carbon compound that is immediately converted into two three-carbon compounds. This process is called carbon fixation, because CO2 is “fixed” from its inorganic form into organic molecules.
ATP and NADPH use their stored energy to convert the three-carbon compound, 3-PGA, into another three-carbon compound called G3P. This type of reaction is called a reduction reaction, because it involves the gain of electrons. A reduction is the gain of an electron by an atom or molecule. The molecules of ADP and NAD+, resulting from the reduction reaction, return to the light-dependent reactions to be re-energized.
One of the G3P molecules leaves the Calvin cycle to contribute to the formation of the carbohydrate molecule, which is commonly glucose (C6H12O6). Because the carbohydrate molecule has six carbon atoms, it takes six turns of the Calvin cycle to make one carbohydrate molecule (one for each carbon dioxide molecule fixed). The remaining G3P molecules regenerate RuBP, which enables the system to prepare for the carbon-fixation step. ATP is also used in the regeneration of RuBP.
Figure 5.15 The Calvin cycle has three stages. In stage 1, the enzyme RuBisCO incorporates carbon dioxide into an organic molecule. In stage 2, the organic molecule is reduced. In stage 3, RuBP, the molecule that starts the cycle, is regenerated so that the cycle can continue.
In summary, it takes six turns of the Calvin cycle to fix six carbon atoms from CO2. These six turns require energy input from 12 ATP molecules and 12 NADPH molecules in the reduction step and 6 ATP molecules in the regeneration step.
CONCEPT IN ACTION
The following is a link to an animation of the Calvin cycle. Click Stage 1, Stage 2, and then Stage 3 to see G3P and ATP regenerate to form RuBP.
PHOTOSYNTHESIS
The shared evolutionary history of all photosynthetic organisms is conspicuous, as the basic process has changed little over eras of time. Even between the giant tropical leaves in the rainforest and tiny cyanobacteria, the process and components of photosynthesis that use water as an electron donor remain largely the same. Photosystems function to absorb light and use electron transport chains to convert energy. The Calvin cycle reactions assemble carbohydrate molecules with this energy.
However, as with all biochemical pathways, a variety of conditions leads to varied adaptations that affect the basic pattern. Photosynthesis in dry-climate plants (Figure 5.16) has evolved with adaptations that conserve water. In the harsh dry heat, every drop of water and precious energy must be used to survive. Two adaptations have evolved in such plants. In one form, a more efficient use of CO2 allows plants to photosynthesize even when CO2 is in short supply, as when the stomata are closed on hot days. The other adaptation performs preliminary reactions of the Calvin cycle at night, because opening the stomata at this time conserves water due to cooler temperatures. In addition, this adaptation has allowed plants to carry out low levels of photosynthesis without opening stomata at all, an extreme mechanism to face extremely dry periods.
The Calvin cycle (article)
How the products of the light reactions, ATP and NADPH, are used to fix carbon into sugars in the second stage of photosynthesis.
Photosynthesis
The Calvin cycle
How the products of the light reactions, ATP and NADPH, are used to fix carbon into sugars in the second stage of photosynthesis.
Google ClassroomFacebookTwitter
Introduction
You, like all organisms on Earth, are a carbon-based life form. In other words, the complex molecules of your amazing body are built on carbon backbones. You might already know that you’re carbon-based, but have you ever wondered where all of that carbon comes from?
As it turns out, the atoms of carbon in your body were once part of carbon dioxide (
\text {CO}_2 CO 2
start text, C, O, end text, start subscript, 2, end subscript
) molecules in the air. Carbon atoms end up in you, and in other life forms, thanks to the second stage of photosynthesis, known as the Calvin cycle (or the light-independent reactions).
Overview of the Calvin cycle
In plants, carbon dioxide (
\text{CO}_2 CO 2
start text, C, O, end text, start subscript, 2, end subscript
) enters the interior of a leaf via pores called stomata and diffuses into the stroma of the chloroplast—the site of the Calvin cycle reactions, where sugar is synthesized. These reactions are also called the light-independent reactions because they are not directly driven by light.
In the Calvin cycle, carbon atoms from
\text {CO}_2 CO 2
start text, C, O, end text, start subscript, 2, end subscript
are fixed (incorporated into organic molecules) and used to build three-carbon sugars. This process is fueled by, and dependent on, ATP and NADPH from the light reactions. Unlike the light reactions, which take place in the thylakoid membrane, the reactions of the Calvin cycle take place in the stroma (the inner space of chloroplasts).
This illustration shows that ATP and NADPH produced in the light reactions are used in the Calvin cycle to make sugar.
Image credit: "The Calvin cycle: Figure 1," by OpenStax College, Concepts of Biology CC BY 4.0
Reactions of the Calvin cycle
The Calvin cycle reactions can be divided into three main stages: carbon fixation, reduction, and regeneration of the starting molecule.
Here is a general diagram of the cycle:
Diagram of the Calvin cycle, illustrating how the fixation of three carbon dioxide molecules allows one net G3P molecule to be produced (that is, allows one G3P molecule to leave the cycle).
3 \text {CO}_2 CO 2
start text, C, O, end text, start subscript, 2, end subscript
molecules combine with three molecules of the five-carbon acceptor molecule (RuBP), yielding three molecules of an unstable six-carbon compound that splits to form six molecules of a three-carbon compound (3-PGA). This reaction is catalyzed by the enzyme rubisco.
In the second stage, six ATP and six NADPH are used to convert the six 3-PGA molecules into six molecules of a three-carbon sugar (G3P). This reaction is considered a reduction because NADPH must donate its electrons to a three-carbon intermediate to make G3P.
Regeneration. One G3P molecule leaves the cycle and will go towards making glucose, while five G3Ps must be recycled to regenerate the RuBP acceptor. Regeneration involves a complex series of reactions and requires ATP.[See a diagram that shows the molecular structures]
Carbon fixation. A\text {CO}_2 CO 2
start text, C, O, end text, start subscript, 2, end subscript
molecule combines with a five-carbon acceptor molecule, ribulose-1,5-bisphosphate (RuBP). This step makes a six-carbon compound that splits into two molecules of a three-carbon compound, 3-phosphoglyceric acid (3-PGA). This reaction is catalyzed by the enzyme RuBP carboxylase/oxygenase, or rubisco. [Details of this step]
Reduction. In the second stage, ATP and NADPH are used to convert the 3-PGA molecules into molecules of a three-carbon sugar, glyceraldehyde-3-phosphate (G3P). This stage gets its name because NADPH donates electrons to, or reduces, a three-carbon intermediate to make G3P. [Details of this step]Regeneration. Some G3P molecules go to make glucose, while others must be recycled to regenerate the RuBP acceptor. Regeneration requires ATP and involves a complex network of reactions, which my college bio professor liked to call the "carbohydrate scramble."^1 1
start superscript, 1, end superscript
In order for one G3P to exit the cycle (and go towards glucose synthesis), three
\text {CO}_2 CO 2
start text, C, O, end text, start subscript, 2, end subscript
molecules must enter the cycle, providing three new atoms of fixed carbon. When three
\text {CO}_2 CO 2
start text, C, O, end text, start subscript, 2, end subscript
molecules enter the cycle, six G3P molecules are made. One exits the cycle and is used to make glucose, while the other five must be recycled to regenerate three molecules of the RuBP acceptor.
Guys, does anyone know the answer?