mee Flashcards
(21 cards)
What is an autotroph?
Organism that makes its own food (producer)
Autotrophs are essential for ecosystems as they form the base of the food chain.
Define photoautotroph.
Organism that uses light energy to make its own food
Photoautotrophs include plants, algae, and some bacteria.
What is carbon fixation?
The building up of organic carbon compounds from inorganic carbon
This process is crucial for converting CO2 into usable forms of carbon.
Where does photosynthesis take place?
In chloroplasts, mostly in the leaves of plants
Chloroplasts contain the necessary pigments and structures for photosynthesis.
What is the role of stomata in photosynthesis?
Carbon dioxide and oxygen diffuse in and out of the leaf through stomata
Stomata are small openings that regulate gas exchange.
What is the function of xylem vessels?
Water is drawn up from the roots through xylem vessels
Xylem transports water and minerals from the roots to the rest of the plant.
What are the main structures of a chloroplast?
Inner and outer membrane, thylakoids, thylakoid membrane, thylakoid space, stroma
Thylakoids are organized into stacks called grana.
Write the balanced equation for photosynthesis.
6CO2 + 6H2O → C6H12O6 + 6O2
This equation summarizes the overall process of photosynthesis.
What happens to carbon dioxide during photosynthesis?
Carbon dioxide is reduced to form sugar (gains hydrogen)
This reduction is part of the Calvin cycle.
What is the main by-product of photolysis of water?
Oxygen
This oxygen is released into the atmosphere.
What is photophosphorylation?
Electron transport chain uses the energy of the electrons to pump H+ ions into the thylakoid space
This process generates ATP through chemiosmosis.
What is the role of NADP+ in photosynthesis?
NADP+ is reduced to NADPH during the light reactions
NADPH carries electrons and H+ ions to the Calvin cycle.
What occurs during the carbon fixation step of the Calvin cycle?
Carbon dioxide is added to RuBP by the enzyme Rubisco
This forms an unstable 6-carbon compound that breaks down to form 3-PGA.
What is G3P in the context of photosynthesis?
The product of photosynthesis, a 3-carbon sugar used to make glucose and other carbohydrates
G3P is crucial for plant metabolism.
What is photorespiration?
A wasteful process whereby rubisco adds oxygen to RuBP instead of carbon dioxide
This occurs when stomata close to conserve water.
What characterizes C3 photosynthesis?
Initial fixation of CO2 in Calvin cycle forms a C3 compound (3-PGA)
It is most efficient in cooler, wetter conditions.
What is the primary advantage of C4 photosynthesis?
Allows photosynthesis to take place without photorespiration even when stomata are partly closed
This adaptation is beneficial in hot environments.
What is unique about CAM photosynthesis?
Initial CO2 fixation occurs at night to form organic acid
This process allows stomata to remain closed during the day.
List the importance of photosynthesis.
- Provides food for the whole food chain
- Source of oxygen gas
- Makes respiration possible
- Source of ozone layer
- Removes CO2 from the atmosphere
- Important for climate change
Photosynthesis is vital for life on Earth.
True or False: CO2 is a greenhouse gas.
True
Greenhouse gases contribute to global warming.
What impact does burning fossil fuels have on photosynthesis?
Releases CO2 that was removed by photosynthesis over many millions of years
This contributes to increasing global temperatures.
