BIO Unit 3 Chp5-6 Flashcards
(21 cards)
what is the phototsynthesis chemical equation
6CO2 + 6H2O > C6H12O6 +6O2
carbon dioxde + water (light energy and chlorophyll)>glucose + oxgyen + water
what is chloroplast
a membrane bound organelle only found in plant/photoautographs cells that are site of photosynthesis
what is chlorophyll
pigments which are found in the thykaloid of chloroplasts responsible for absrobing light energy in photosynthesis
what is stomata
a small pore on the leaf’s surface that opens and closes to regulate gas exchange, allowing carbon dioxide in the atmosphere to diffuse into the leaf
what is xylem
vascular tissue in plants responsible for transporting water and minerals from the roots to the leaves
what is light dependant stage
The first stage of photosynthesis, where light energy splits water molecules into oxygen and hydrogen inside the thylakoid membranes
steps of light dependant stage
- Sunlight excites an electron within chlorophyll.
- Water absorbed by a plant’s root hairs is split into O2 and H+ as it donates one electron to the chlorophyll.
- The excited electron and H+ ion from water lead to the production of the coenzymes NADPH and ATP.
- The oxygen is released out of the chloroplast, and the coenzymes are ready for the second stage of photosynthesis.
where does light dependent stage occur
thykaloid membranes
what are the inputs and outputs of light dependant stage
input:
H2O
NADP+
18ADP + pi
output:
O2
NADPH
18ATP
what is light independent stage
The second stage of photosynthesis where carbon dioxide is used to form glucose in the stroma of a chloroplast (dark stage)
steps of light independant stage
- CO2 collected from the stomata in leaves enters a cyclic reaction.
- The carbon, from CO2, undergoes reactions powered by ATP and NADPH to produce a series of carbon-based molecules.
- Eventually, a specific carbon molecule is reached that goes on to contribute to the formation of glucose, with water also being produced in this stage.
where does light independant stage occur
stroma
what are inputs and output of light independant stage
input:
CO2
NADP+
ATP
output:
glucose (c6h12o6)
NADP+
ADP+pi
H2O
what is rubisco
enzyme involved in light independent stage
-controls first reaction in LI stage
-responsible for initial stages in CO2
-CO2 and O2 substrates for rubisco
CO2 binds to rubisco …
photosynthesis (Calvin cycle) can be completed, glucose is produced and plants can grow/survive
O2 binds to rubisco …
photorespiration occurs
what is photorespiration
a wasteful pathway and is unwanted in plants and energy used in these reactions are wasted. Photosynthesis is also disrupted as rubisco did not bind to CO2 so no glucose is produced. Plants survival and grow may be impacted
what is C3 plants
-Classified as normal plants
-Most common
-Live in colder environment
-No adaptations to resist in photorespiration.
-Photosynthesis occurs in mesophyll cells
-Initial carbon fixation by rubisco occurs in the same cell/location as the rest of the calvin cycle.
what is C4 plants
-Hot
-Photosynthesis occurs in both mesophyll cells and bundle-sheath cells.
-Initial carbon fixation occurs in mesophyll cells by PEP carboxylase into 4-carbon molecule which is then converted into malate
-Malate is transported to bundle sheath cells, where rubisco is
-This increases the carbon dioxide concentration around rubisco, ensuring the calvin cycle is completed, producing glucose
what is CAM plants
-Hot and dry
-Stomata are closed during the day to conserve water
-Stomata opens at night allowing CO2 to enter mesophyll cells
-Initial carbon fixation occurs by PEP carboxylase converting it to 4-carbon and malate
-Malate is stored in vacuoles overnight
-During the day, the light-dependent stage reactions begin. Malate is released and travels to rubisco increasing concentration of CO2 and rubisco. Calvin cycle continues and glucose is produced
