Light Dependant Phase Flashcards
(24 cards)
What is the first step in the light dependent phase?
Water molecule absorbed into chloroplast.
What happens to the water molecule in the light dependent phase?
Sunlight cuts water molecule into hydrogen and oxygen.
Why is hydrogen important in the light dependent phase?
So there is access to the high energy hydrogen atoms.
What is released as a byproduct of the light dependent phase?
Oxygen is given off.
What is created by fusing a phosphate to ADP?
ATP is created.
This is an energy investment for the light independent phase.
What happens to the remaining hydrogen in the light dependent phase?
It is picked up by a co-enzyme (NADP).
This allows hydrogen to be transported into the light independent phase.
What are the products of the light dependent phase?
ATP and NADPH.
Where does the light dependent phase occur?
In the thylakoids.
What is the light dependent phase often referred to as?
The ‘charging’ phase.
When must the light dependent phase occur?
Before the light independent phase.
What is the most important substance harvested in the light dependent phase?
Hydrogen.
What is absorbed from the atmosphere during photosynthesis?
Carbon dioxide is absorbed from the atmosphere.
What is combined to form carbohydrates during photosynthesis?
Carbon dioxide and energy rich Hydrogen (H*) atoms are combined using ATP to form carbohydrates (glucose).
Where is excess glucose stored?
Excess glucose is stored as starch in starch granules.
Can the phase of photosynthesis that involves glucose formation occur in the absence of light?
Yes, this phase can take place in the presence or absence of light because light is not required during this phase.
What does Table 3 provide an overview of?
Table 3 provides a short overview of the different phases of photosynthesis.
What is the starch test used for?
The starch test is used to see if photosynthesis has actually occurred.
How does light intensity affect photosynthesis?
As light intensity increases, so does the rate of photosynthesis. Light intensity can increase photosynthesis even when temperature is not at optimum.
What is a method to measure the rate of photosynthesis?
We measure the rate of photosynthesis by how many oxygen bubbles are produced during a time interval. More bubbles indicate faster photosynthesis.
What is the optimum temperature for photosynthesis?
The optimum temperature for photosynthesis is 25 degrees.
What happens to photosynthesis if the temperature exceeds the optimum?
If the temperature continues to increase beyond optimum, the enzymes will denature and photosynthesis will decrease.
How can temperature be tested in an experiment?
A plant is placed in various temperatures and the rate of photosynthesis is measured.
How does carbon dioxide concentration affect photosynthesis?
As carbon dioxide increases, so does the rate of photosynthesis. However, if it increases beyond the optimum, it will decrease photosynthesis.
What is a method to measure carbon dioxide’s effect on photosynthesis?
A plant is exposed to various levels of carbon dioxide and the rate of photosynthesis is recorded.
