plants
Which of the following are autotrophs?
ATP
One of the principal chemical compounds that living things use to store energy is…
van Helmont
Which scientist concluded that most of a growing plant’s mass comes from water?
Water and carbon dioxide
In addition to light and chlorophyll, photosynthesis requires…
Reflects green light
The leaves of a plant appear green because chlorophyll…
Sugars and oxygen
The products of photosynthesis are…
Light absorption
The first process in the light-dependent reactions of photosynthesis is…
NADPH
Which substance from the light-dependent reactions of photosynthesis is a source of energy for the Calvin cycle?
Calvin cycle
The light-independent reactions of photosynthesis are also known as the …
-Autotrophs are able to obtain energy by making their own food.
-Heterotrophs obtain their energy by consuming food.
-Heterotrophs obtain their energy by consuming food.
How do heterotrophs and autotrophs differ in the way they obtain energy?
1. Nitrogen-containing compound called adenine
2. Sugar called ribose
3. Three phosphate groups
2. Sugar called ribose
3. Three phosphate groups
Describe the three parts of the ATP molecule.
-ATP resembles a fully charged battery because it can yield energy when the third phosphate is removed, also forming ADP.
-ADP is like a partially charged battery that can be recharged when energy is added to link a third phosphate group, reforming ATP.
-ADP is like a partially charged battery that can be recharged when energy is added to link a third phosphate group, reforming ATP.
Use the analogy of a battery to explain how energy is stored in and released from ATP
A single molecule of glucose stores more than 90 times the energy stored by ATP. However, ATP, which transfers energy quickly, is used by the cell as an immediate source of energy.
Compare the amounts of energy stored by ATP and glucose. Which compound is used by the cell as an immediate source of energy?
-Priestly discovered that plants produce a substance needed to burn candles, now known to be oxygen.
-Ingenhousz found that plants produce oxygen only when exposed to light.
-Ingenhousz found that plants produce oxygen only when exposed to light.
How were Priestly’s and Ingenhousz’s discoveries about photosynthesis related?
Carbon dioxide + water -> sugars and oxygen
Write the basic equation for photosynthesis using the names of the starting and final substances of the process.
Plant pigments absorb energy from light and transfer it to electrons involved in photosynthesis.
What role do plant pigments play in the process of photosynthesis?
A: chloroplast
B: stroma
C: granum
D: thylakoid
– The light-dependent reactions take place in the thylakoids.
-The Calvin cycle takes place in the stroma
B: stroma
C: granum
D: thylakoid
– The light-dependent reactions take place in the thylakoids.
-The Calvin cycle takes place in the stroma
Identify the structures labeled A, B, C, and D. In which structures(s) do the light-dependent reactions occur? In which structure(s) does the Calvin cycle take place?
(picture)
(picture)
NADP+ carries energy by holding two electrons and a hydrogen ion. It carries the stored energy to other reactions that help build sugar molecules.
Explain the role of NADP+ as an energy carrier in photosynthesis.
ATP synthase is a protein found in the thylakoid membrane that allows H+ ions to pass through it. As H+ ions pass through this protein, it rotates and binds ADP and a phosphate group together to produce ATP.
What is the role of ATP synthase? How does it work?
During the Calvin cycle, plants use the energy that ATP and NADPH contain to build high-energy compounds that can be stored for a long time. The Calvin cycle uses six molecules of carbon dioxide to produce a single 6-carbon sugar molecule.
Summarize what happens during the Calvin cycle.
The Calvin cycle uses the ATP and NADPH produced during the light-dependent reactions to produce high-energy sugars.
How do the events in the Calvin cycle depend on the light-dependent reactions?
1. Temperature
2. Amount of available water
3. Intensity of light
2. Amount of available water
3. Intensity of light
Describe three factors that affect the rate at which photosynthesis occurs.
The chlorophyll may be broken down by the cooling temperatures or the changing light, so the green color disappears. The leaf then shows the color of its remaining pigment(s).
Some plant leaves contain yellow and red pigments as well as chlorophyll. In the fall, these leaves may become red or yellow. Suggest an explanation for those color changes.
ADP is like a ball at the bottom of the hill. Moving the ball to the top of the hill is like adding a phosphate group and making ATP. The ball now has the energy to roll downhill and move other objects in its path. ATP has energy to help change molecules.
Develop an analogy to explain ATP and energy transfer to a classmate who does not understand the concept.
No step in the Calvin cycle depends directly on light. Instead, it uses energy stored in the molecules ATP and NADPH.
The Calvin cycle is sometimes described as the light-independent reactions. Give evidence to support the idea that the Calvin cycle does not depend on light.
Start with two samples of the same amount and type of pond algae in water. Put one sample in the dark and the other in a location that receives daylight, keeping the temperatures the same. After two weeks, compare the two samples to determine the amount and health of the algae.
Design an experiment that uses pond water and algae to demonstrate the importance of light energy to pond life. Be sure to indentify the variables you will control and the variable you will change.
The closer the plant is to the light, the more oxygen is produced. This occurs because more light energy is reaching the algae cells and thus is available for photosynthesis.
NOTE: Would getting any closer necessarily make more oxygen bubbles?
NO! At some point, the enzymes will be maxed out!
NOTE: Would getting any closer necessarily make more oxygen bubbles?
NO! At some point, the enzymes will be maxed out!
What relationship exists between the distance from the plant to the light and the number of bubbles produced? Explain your answer.
At first, photosynthesis would take place during daylight, but it would stop when the water was used up. If no more water was added, the plant might die.
Suppose you water a potted plant and place it by a window in an airtight jar. Predict when photosynthesis might occur over the next few days. Would you expect the pattern to change if the plant were left there for several weeks?
Because the Indian pipe plant has no chlorophyll or other pigment involved in photosynthesis, it probably can not make its own food. Therefore, it must obtain food from other sources the way a heterotroph does. Perhaps it absorbs partly decayed food from the soil like mushrooms (fungi) do.
Examine the photograph of the Indian pipe plant shown below. What can you conclude about the ability of the Indian pipe plant to make its own food?
(picture)
(picture)
chlorophyll
The principal pigment in plants that captures sunlight energy is…
sugars
Which of the following is NOT produced in the light-dependent reactions of photosynthesis?
water + carbon dioxide -> sugars + oxygen
Which equation best summarizes the process of photosynthesis?
green
The color of light that is LEAST useful to a plant during photosynthesis is…
absorption of light energy
The first step in photosynthesis is the…
oxygen
In a typical plant, all of the following factors are necessary for photosynthesis EXCEPT:
contain several pigments
A valid conclusion that can be drawn from this information is that spinach leaves…
chloroplasts
In which organelles would most of the pigments be found?
