Like cellular respiration, you need to apply your knowledge of chemistry.
You will need to know the names of important molecules, describe their sequence in the process of metabolism, and describe how the processes accomplish their objectives.
Photosynthesis is the process of capturing free energy in the sun and storing it in chemical bonds.
The general chemical equation describing photosynthesis is 6 CO2 + 6 H2O + light - C6H12O6 + 6 O2 The processes are connected because the energy stored in chemical bonds by respiration is used to make adenosine triphosphate.
A pigment molecule can only absorb light in a narrow range of wavelength.
They complement each other to maximize energy absorption.
The energy from the light is incorporated into the electrons within the atoms that make up the molecule.
The energy is absorbed by a nearby molecule.
The process of energy absorption, followed by energy re-emission, continues with the energy bouncing from one molecule to another.
The two chlorophyll molecules named with numbers that represent the wavelengths at which they absorb their maximum amounts of light are different from the rest of the chlorophyll molecule because of their association with nearby pigments.
The photosystem I is made up of chlorophyll P700 and the other pigments.
The photosystem II is formed by chlorophyll P680.
Refer to the figure as you read the descriptions.
Electrons trapped in photosystem II are powered by light.
Two electrons are passed to a molecule.
The first in a chain of electron acceptors is called the "primary" electron acceptor.
The electrons from one carrier to the next are passed through this chain.
The electron transport chains in photosynthesis are similar to those in the inner mitochondria.
The two electrons lose energy when they move down the electron transport chain.
The energy lost by the electrons as they pass along the electron transport chain is phosphorylate.
The electron transport chain ends with PS I.
The electrons are passed to a primary electron acceptor, which is different from the one associated with PS II.
Two electrons are moving through a transport chain.
At the end of the chain, the two electrons combine with the other two.
Like NADH in respiration, NADPH forms an energy-rich molecule.
The two electrons that came from PS II are now in NADPH.
When H2O is split into two electrons, 2 H+ and 1/2 O2, the loss of these two electrons is replaced.
The two electrons from H2O replace the lost electrons from PS II, one of the H+ provides the H in NADPH, and the 1/2 O2 contributes to the oxygen gas that is released.
Photophosphorylation takes the energy in light and the electrons in H2O to make energy-rich molecules.
In this sequence, electrons from PS I join with carriers from the electron transport chain.
In contrast to noncyclic photophosphorylation, the electrons return to PS I.
They can participate in photophosphorylation here.
Cyclic photophosphorylation and noncyclic photophosphorylation occur at the same time.
The two electrons passing through the photophosphorylation generate a small amount of energy.
That is, it takes CO2 that is unreactive and puts it into an organic molecule that can be used in biological systems.
A single molecule of sugar is produced by the biosynthetic pathway.
The Calvin cycle has to repeat six times in order to accomplish this.
G3P is a very energy-rich molecule because the energy in the ATP and NADPH molecule is incorporated into it.
The conversion of 10 G3P to 6 RuBP is done with 6 ATP.
The cycle can be repeated if the 6 RuBP is re-generated.
Only 10 of the 12 G3P were used in step 3.
The two remaining G3P are used to build sugar.
Fructose and maltose can also be formed.
Disaccharides, like sucrose, and polysaccharides, can be formed by combining the glucose molecule with another molecule.
No light is used in the Calvin cycle.
The Calvin cycle occurs in the presence of light.
The two energy-rich molecule can be created only during photophosphorylation, which can occur only in light.
The Calvin cycle takes CO2 from the atmosphere and the energy in ATP and NADPH to create a molecule.
The sun's energy is represented by the energy in ATP and NADPH.
Both light dependent and light independent reactions of photosynthesis occur in Chloroplasts.
There is a double layer oflipids in this membrane.
There is a narrow area between the inner and outer membranes.
A doublelipid bilayer is also found in this second membrane.
The stroma is the fluid that fills the inside.
The Calvin cycle involves fixing carbon from CO2 to make G3P.
There are stacks of pancake-like membranes suspended in the stroma.
The photosystems PS I and PS II and other electron carriers of the light-dependent reactions are contained in the membranes of the thylakoids.
The inside of the thylakoid is where H+ ion accumulate.
The spatial arrangement of the respiratory processes is similar to that of the photosynthetic processes.
The process in chloroplasts is similar to the process in mitochondria.
The electron transport chain between PS II and PS I (1B) carries H+ from the stroma into the lumen.
There are differences in the concentration of H+ between the stroma pH 8 and the thylakoid pH 5.
The electric gradient is created by the H+ ion accumulating on the inside of the thylakoid.
ATP is generated.
The energy generated by the passage of the H+ turbine is similar to the energy generated by the water through a dam.
The passage of 3 H+ is needed to generate 1 ATP.
The Calvin cycle uses a number of substances to produce G3P.
At the end of the electron transport chain, electrons combine with H and NADP.
Because of its function in catalyzing the fixation of CO2 in all photosynthesizing plants, rubisco is the most common protein on Earth.
It is not very efficient.
It is also able to fix oxygen.
The CO2 fixing efficiency is reduced because rubisco fixes O2 as well.
The second problem is that the products formed when O2 is combined with RuBP do not lead to the production of useful, energyrich molecules.
Plants make a lot of effort to rid the cell of the products of photorespiration.
It is believed that the early evolution of rubisco was not influenced by its O2 fixing handicap.
There are giant tube worms growing in the deep ocean.
A review of the material presented in this chapter is provided by the questions that follow.
They can be used to evaluate how well you understand the concepts.
AP multiple-choice questions are often more general, covering a broad range of concepts.
The two practice exams in this book are for these types of questions.
Four possible answers or sentence completions are followed by each of the following questions or statements.
The one best answer or sentence is what you choose.
There is only one form of the plant.
Green light is absorbed by chlorophyll.
The chlorophyll is found in the thylakoids.
P700 is a bright color.
In the fall, the leaves on the trees turn to various shades of red, orange, and yellow.
The electron transport chain has electrons moving along it.
The electrons are excited.
The molecule is produced.
NADPH is produced.
Each answer can be used more than once.
The Calvin cycle happens in the dark.
The majority of light reactions take place on the stroma membranes.
Light energy is stored.
The questions that follow are typical of an entire AP exam question or just that part of a question that is related to this chapter.
There are two types of questions on the AP exam.
It takes about 20 minutes to answer a long free-response question.
Sometimes they offer you a choice of questions to answer.
6 minutes is the time it takes to answer a short free-response question.
diagrams can be used to supplement your answers, but a diagram alone is not adequate.
There are different types of light absorbers in the chloroplasts.
Explain in two or three sentences the purpose of having a variety of light-absorbing pigments.
There are particles inside the thylakoids.
Explain the purpose in two or three sentences.
The light-absorbing pigments and most of the light reactions are found in the thylakoid membranes.
The green light reflects the light we see.
Carotenoids look orange or yellow because they reflect those colors.
The leaves turn to these colors because the tree begins to break down the chlorophyll in the leaves.
Carotenoids are visible in the absence of chlorophyll.
Other colors can be seen from carotenoids that are still intact.
The products of noncyclic photophosphorylation are NADPH, ATP, and O2.
In order to decrease potential energy, the molecule mentioned in the question are starch, glucose, NADPH, and ATP.
There is a substance called stear.
A single NADPH can provide about 3 ATP molecules, while a single glucose molecule can provide about 30.
Noncyclic photophosphorylation is how NADPH is produced.
During the Calvin cycle, CO2 and RuBP combine to cause the first step of carbon fixation.
When CO2 and O2 combine, photorespiration occurs.
H2O2 is generated and subsequently broken down when the product of this reaction is transported to a peroxisome.
The products of noncyclic photophosphorylation are energy-rich.
An electron transport chain is formed during photophosphorylation.
As long as there is sunlight, this process can repeat.
H2O and CO2 are not needed for photophosphorylation.
The photophosphorylation process takes place in the thylakoid membranes.
The splitting of water takes place on the inner side of the thylakoid membrane, because of the embedded manganese-containingProtein complex.
The splitting of H2O gives electrons.
During the Calvin cycle, the electrons are incorporated in NADPH.
It is not an answer choice if it is light.
The Calvin cycle and noncyclic photophosphorylation are part of the diagram.
The first two arrows are H2O and light and the third is ADP.
The ADP is recycled.
In photophosphorylation,ADP is used.
NADP+ is already shown in the figure, so the choice is not given.
That is not an answer choice.
The Calvin cycle requires CO2, which is represented by Arrow 7.
The Calvin cycle fixes CO2 and produces G3P.
The Calvin cycle requires photophosphorylation in light.
Calvin cycle activity is measured by CO2 absorption.
The end product of photosynthesis is generated by the Calvin cycle.
The factors that influence the rate are provided in the other answer choices.
CO2 is only indicative of the amount of photosynthetic activity, not the rate at which it is occurring.
When there is more CO2 in the growth chamber and less O2 in the left side of the graph, CO2 is taken up more.
Lower concentrations of O2 reduce photorespiration.
If there were only one light absorbing pigment, the cell would absorb less light energy.
The formation of NADPH is made possible by the electrons.
The Calvin cycle is where the electrons are passed to, so that they can contribute to the regeneration and formation of carbohydrates.
A pH and electrical gradient can be created by theAccumulation of protons in the thylakoid lumen.
The movement of protons is driven by the gradient and the movement of ADP is driven by the gradient.
Photosynthesis is the process by which water and light energy are used.
The total equation is 6 H2O + 6 CO2 + light - C6H12O6 + 6 O2 The purpose of a variety of pigments is to absorb light energy.
The absorption spectrums of the pigments overlap.
The light energy is absorbed by the pigment.
Thepigment systems I and II are separate photosystems.
Cyclic photophosphorylation involves photosystem I.
The P700 captures the energy absorbed by the pigment system.
Two electrons are excited to a higher energy level, where they are absorbed by a primary electron acceptor.
The electrons are passed through an electron transport chain from the electron acceptor to the electron acceptor.
The energy loss of electrons is used to bond a group to another group.
The energy from the two electrons is trapped in an ATP molecule, which is the result of the process called Phosphory.
When the two electrons return to the photo system, the cycle is complete.
Both photosystems I and II are involved in noncyclic photophosphorylation.
When photon energy is trapped by chlorophyll P680 in photosystem II, it begins.
The two electrons are passed to a primary electron acceptor, and then through an electron transport chain, producing 1.5 ATP and being returned to photosystem I.
The electrons are received by another electron acceptor.
The two electrons combine with 2 H+ to form NADPH.
The water molecule is split into two parts, producing 2 electrons, 2 H+, and 1/2 O2.
The electrons are replaced by 2 electrons.
Oxygen is released.
Two electrons from noncyclic photophosphorylation are combined with one of the H+ to produce NADPH.
The Calvin cycle uses NADPH to supply energy.
The Calvin cycle combines CO2, NADPH, and ATP to form G3P.
It takes 6 CO2 to create 2 G3P, so the cycle repeats six times.
It can be broken down to release its store of energy in the form of ATP, which can be used to make other sugars.
This answer is thorough.
To discuss these processes as they occur in the chloroplast is another way to answer this question.
You would get points for illustrations such as those in thischapter.