Chapter 8
Light Dependent Reactions ( LDR )
They require the direct involvement of light and light and absorbing pigments, uses energy from sunlight to produce energy rich compounds such as ATP
Electron transport chain
A series of electron carrier proteins that shuttle high energy electrons during ATP generating reactions
Light Independent Reactions ( LIR )
ATP AND NADPH molecules produced in light-dependent reactions are used to produced high-energy sugars from carbon dioxide
Which of the following is NOT a step in the light-dependent reactions?
ATP and NADPH are used to produce high-energy sugars.
Products of light dependent reactions
ATP, NADPH and Oxygen gas
NADP+
Accepts and holds 2 high energy electrons along with a hydrogen ion (H+)
Three parts of ATP molecule
Adenine , ribose and 3 phosphate
Which of the following is NOT a part of an ATP molecule?
Chlorophyll
Thylakoids
Chloroplasts contain an ambulance of saclike photosynthetic membrane
Most plants appear green because chlorophyll
Does not absorb green light
What action contributes to the inside of the thylakoid membrane becoming positively charged during the light-dependent reactions?
H+ ions are released as water splits
Which pathway represents the flow of electrons during photosynthesis?
H2O > NADP+ > Calvin cycle
Calvin cycle takes place
Light independent reaction
If carbon dioxide is completely removed from a plant's environment, what would you expect to happen to the plant's production of high-energy sugars?
No sugars will be produced
Autotrophs
Organisms that make their own food
Heterotrophs
Organisms that obtain food by consuming other living things
A student is collecting the gas given off from a plant in bright sunlight at a temperature of 27°C. The gas being collected is probably
Oxygen
In the overall equation for photosynthesis, six molecules of carbon dioxide and six molecules of water result in a molecule of sugar and six molecules of.
Oxygen
Photosynthesis
Plants absorb sunlight
Pigments
Plants gather the sun's energy with light absorbing molecules
Calvin cycle
Plants use the energy that ATP and NADPH contain to build stable high energy carbohydrate compounds that can be stored for a long time.
ATP synthase
Spans the membrane and allows H+ ions to pass through it.
Grana
Stack of thylakoids
How does the Calvin cycle differ from the light-dependent reactions?
The Calvin cycle uses the ATP and NADPH produced during the light-dependent reactions to produce high-energy sugars.
Where are Photo systems 1 and 2 found
The Thylakoid membrane
ATP
The compounds the cells use to store and release energy like Adenosine and 5-Carbon sugar.
What happens when chlorophyll is struck by sunlight?
The electrons in the chlorophyll molecules become energized.
Stroma
The fluid portion of the chloroplast, outside of the thylakoids
Chlorophyll
The plant's principal pigment
If you continue to increase the intensity of light that a plant receives, what happens?
The rate of photosynthesis increases indefinitely with light intensity.
Where in the chloroplast is chlorophyll found?
Thylakoid
Photosystems
Thylakoids contain clusters of chlorophyll and proteins
Energy is released from ATP when
When a phosphate group is removed
What happens during photosynthesis?
light energy is converted to chemical energy and then stored in the form of bonds of sugar.
Where do the light-dependent reactions take place?
within the thylakoid membranes
