Photosynthesis Flashcards
Inputs to light dependent reaction (LDR)
Water
ADP + Pi
NADP+
Light* not a chemical if asked for chemical inputs
Outputs to LDR
Oxygen
ATP
NADPH
Inputs to light independent reaction (LIR)
Carbon dioxide
ATP
NADPH
Outputs to LIR
Glucose
ADP + Pi
NADP+
State the the role of the co-enzyme NADPH in photosynthesis
NADP+ carries hydrogen ions and electrons by forming NADPH and moves from the light dependent reaction to the light independent reaction in a cyclical manner.
State the the role of the co-enzyme ATP in photosynthesis
ADP carries energy by forming ATP and moves from the light dependent reaction to the light independent reaction in a cyclical manner.
State the role of Rubisco in all plants
Catalyse reducing carbon dioxide to form glucose in the light independent reaction in the stroma of a chloroplast.
State the name of the process when Rubisco is competitively inhibited by oxygen
Photorespiration
State where C4 plants evolved and how their reactions of the light indendendent reaction differs from C3 plants
Hot dry conditions.
They separate parts of the LIR in different places and also use PepCase. Part of the LIR occurs in the mesophyll then part occurs in the bundle sheath.
State where CAM plants evolved and how their reactions of the light indendendent reaction differs from C3 plants
Very hot dry conditions.
Separate based on time, LIR in day and night.
Role of the chloroplast
Site of photosynthesis
Location of Light dependent reaction within the chloroplast
Grana
Location of light independent reaction within the chloroplast
Stroma
Coenzymes are …
Molecules that are used as loaded or unloaded forms tomove energy (ATP), protons and electrons (NADPH and NAD) between reactions inthe cell in a cyclical manner
Endosymbiotic theory is a theory that ….
Chloroplast and mitochondria originated when a prokaryote engulfed another prokaryote cell speciliased in photosynthesis or energy conversion from glucose to ATP
Evidence to support the endosymbiotic theory of chloroplast origin is ..
Double membrane, Bacterial ribosomal material (70s ribosomes), own DNA (single circular)
Stroma is the …
Fluid, enzyme dense, part of chloroplast where light independent reactions take place.
Granum is the …
Stack of folded thylakoid membranes where the light dependent reactions occur.
Photolysis is when…
Water is split by light energy to make oxygen, hydrogen ions and electrons in the light dependent reaction.
The light independent reaction is also known as …
The Calvin Cycle (memory cue CalvIN, CO2 IN)
List the three main factors that affect the rate of photosynthesis
light intensity, carbon dioxide concentration and temperature
Adaptations of chloroplast structure to perform it’s function are …
Membrane - different internal environment
Folded membrane - increased SA:V increasing reaction rate
Fluids - for movement and reactions
Chlorophyll-light trapping pigment
What is the net production of ATP in photosynthesis?
Zero. The ATP made in the light dependent phase is used in the light independent phase of photosynthesis to form glucose.
State what is found in the grana.
Chlorophyll ( hence GR for Green)
Explain what type of reaction photosynthesis is overall
Endergonic as requires light energy input. Anabolic as forms glucose. Synthesis as it builds up.
Name the co-enzymes used in photosynthesis.
NADP+, ADP +Pi
State the process of the light dependent stage of photosynthesis
photolysis of water
Decribe the process of the light independent stage of photosynthesis
Reduction of CO2 to form glucose. This means that carbon dioxide is gaining hydrogen ions and electrons from NADPH.
What is the reactant of the Calvin cycle?
Carbon dioxide
Which cells within the leaf contain the most chloroplasts?
Palisade Mesophyll
Which colour light is best absorbed by chloroplasts to drive photosynthesis?
Red
How would you measure the rate of photosynthesis?
Measure the products (with a time limit).
E.g. Bubbles (of Oxygen) produced per minute, Volume of oxygen produced after 10 min, Change in oxygen concentration (measured using a probe) after 10 min
What is photorespiration?
Photorespiration is when oxygen binds to Rubisco in place of carbon dioxide (competitive inhibition).
What acts as a competitive inhibitor in photorespiration?
Oxygen
What is the main enzyme used in carbon fixation?
Rubisco
In a C3 plant in what cells does the Light Dependent reaction occur?
Mesophyll cells
In a C3 plant in what cells does the Light Independent reaction occur?
Mesophyll cells
In a C4 plant in what cells does the Light Dependent reaction occur?
Mesophyll cells
In a C4 plant in what cells does the Light Independent reaction occur?
Mesophyll and bundle sheath cells
How is the Light dependent and independent reaction separated in C4 plants?
By location, LDR in the mesophyll, LIR in the Mesophyll and Bundle Sheath
How is the Light dependent and independent reaction separated in CAM plants?
By time, the LDR occurs in the day and the LIR fixation at night (the rest of the LIR occurs during the day but this isn’t when glucose is formed)
In what type of climate do C3 plants exist and flourish?
Cool, wet climate
In what type of climate do C4 plants exist and flourish?
Hot dry climate
In what type of climate do CAM plants exist and flourish?
Very hot and dry climate
What extra enzyme is used in carbon fixation of C4 and CAM plants?
PEPCase
Where does the light dependent reaction occur
In the grana within the chloroplast organelle, within the mesophyll cells/tissue of the leaf.
Explain why a higher temperature increases the rate of photosynthesis.
Because enzymes catalayse all reactions in photosynthesis
Then increasing the temperature will lead to more kinetic energy and more successful collisions between enzymes and substrates and more enzyme substrate complexes
Therefore more product formed and a higher rate of photosynthesis.
