REVIEW: THE LIGHT & DARK REACTIONS OF PHOTOSYNTHESIS
Use your notes on photosynthesis and/or pages 111 – 116 in PH Biology to complete the following. This will be used as a study guide later on so you should correct any wrong answers when we go over this.
Part 1: Fill in the Blank
Photosynthesis is a process using ______(1) energy to make ______(2), a simple carbohydrate molecule with a lot of stored chemical energy. The energy is stored in the ______(3) of the molecule.
The ______(4) is the cellular organelle that photosynthesis takes place in. Within these structures are tiny stacked membranes called grana. These membranes contain the green pigment ______(5) as well as accessory pigments. Accessory pigments such as ______(6) and ______(7) vary in amount from plant species to plant species, and help to absorb wavelengths of light that are not absorbed by the primary plant pigment, ______(8). The light reactions occur on these membranes. The wavelengths (colors) of light that are absorbed by these membranes are mostly ______(9) and ______(10). During the light reactions, ______(11) is split, yielding ______(12), which is released as a gas to the atmosphere, and ______(13) ions. These ions are highly reactive, so they are picked up by a carrier molecule called ______(14), which hangs on to them until the ______(15) reaction, otherwise known as the ______(16) cycle. The energy released from the light reaction is stored in the universal energy storage molecule, called ______(17). The dark reactions occur in lighter, semifluid areas within the chloroplast called stroma. Enzymes produced in this part of the chloroplast produce enzymes needed in the dark reactions, In the dark reaction, ______(18), which is absorbed from the air, is combined with ______(19) released from NADP to make ______(20), a simple sugar. Energy to complete these reactions comes from ______(21) which was made during the light reaction. Any organisms that can make their own food by the process of photosynthesis are known as ______(22) because they feed themselves. The plant may use some of the food it makes during photosynthesis to sustain itself, and excess sugar gets converted to a more complex molecule, ______(23) for more long term storage. Leaves can store this substance, but large amounts of it can be stored in other plant structures such as the ______(24). Heterotrophs are unable to synthesize food for themselves, so they are indirectly dependent on plants for their survival, not just for the food they eat but for the oxygen they breathe.
Part 2: True or False
_____1. Oxygen is given off by green plants both night and day.
_____2. Just as its name implies, the dark reaction occurs only when there is no
light.
_____3. The ATP produced during the light reaction is used during the dark
reaction to make glucose.
_____4. A plant carries on photosynthesis in order to transform light energy into
chemical energy.
_____5. On a scale of increasing energy, ADP has more stored energy than
ATP.
_____6. The pigment contained by all photosynthetic plants is xanthophylls.
_____7. Plants can use light energy directly to carry on their life functions, such
as growth.
Part 3: Multiple Choice
_____1. Which of the following molecules has the most stored energy?\
A. CH4 B. C6H12O6 C. CO2 D. 12H22O11
_____2. Which of the following molecules is a hydrogen carrier?
A. ATP B. NADP C. CO2 D. H20
_____3. The process that is a link between the living and the non-living world is
______, for without it there would be no energy for living
organisms to feed upon.
A. photosynthesis B. fermentation C. cellular respiration
Part 4: Short Answer
In the space below, write a balanced equation for the process of photosynthesis:
In the space below, write a balanced equation for the process of cellular respiration:
In the biosphere, these processes are interdependent and must be balanced. Explain.
What ecological problem is caused by deforestation around the world? Explain.