5A The process of C3 photosynthesis Flashcards
what are Photoautotrophs
organisms that creates their own energy via photosynthesis.
what are mesophyll cells
a plant cell type found in leaves that contain large amounts of chloroplasts.
whats chlorophyll
A chemical found in the thylakoids of chloroplasts. It is responsible for absorbing light energy in photosynthesis.
whats a stoma (pl. stomata):
A small pore on the leaf’s surface that opens and closes to regulate gas exchange
whats the xylem
vascular tissue in plants responsible for transporting water and minerals from the roots to the leaves
whats the thylakoid
a flattened sac-like structure housed inside the chloroplast. Each thylakoid is made up of chlorophyll-containing membrane enclosing a lumen. Thylakoids are the location of the light-dependent stage of photosynthesis.
whats a granum(pl grana)
a stack of thylakoids.
whats photolysis
the process in which molecules are broken down by the action of light (photo = light, lysis = break in two)
whats photosynthesis
Photosynthesis is when light energy is harnessed to produce glucose, the energy source of plants.
Carbon and water are the two inputs needed to produce glucose, oxygen, and water (the outputs). Sunlight is needed to catalyse this reaction.
Glucose is the primary product, and can be used immediately, stored in the form of starch, or to form cellulose.
chemical formula of photosynthesis
6Co2 + 12H2O—sunlight—->C6H12O6 + 602+ 6 H2O
what structures are involved in photsynthesis and what do they do
Leaves are the main site for photosynthesis, and plants maximise their surface area to increase the amount of light hitting it’s surface.
The main leaves that photosynthesise are called mesophyll cells. Chloroplasts, the main organelle where photosynthesis occurs, contain chlorophyll.
Stomata on the leave’s surface open and close to allow for gas exchange and to prevent water loss in a dry environment.
The xylem transports water from the root to photosynthesising cells in the leaves.
whats the light dependent stage?
Only occurs when light is present in the thylakoid membranes that makes up the grana inside a chloroplast.
The purpose of this first stage is to generate the high energy coenzymes NADPH and ATP to power the second stage of photosynthesis.
Inputs in the light-dependent stage are:
12 water (H2O) molecules
12 NADP+
18 ADP + Pi
The outputs of the light-dependent stage are:
6 oxygen (O2) molecules
12 NADPH
18 ATP
whats the light independent stage
The second stage of photosynthesis, glucose is formed from carbon dioxide, NADPH, and ATP through a cycle (Calvin Cycle) of reactions occurring in the stroma of chloroplasts.
Does not require light to occur, and is energised by NADPH and ATP coenzymes produced from the light-dependent stage.
The inputs of the light-independent stage are:
6 carbon dioxide (CO2) molecules
12 NADPH
18 ATP.
The outputs of the light-independent stage are:
glucose (C6H12O6)
6 water (H2O) molecules
12 NADP+
18 ADP + Pi
what are the 4 steps of the light independent stage
- CO2 enter the Calvin cycle and undergoes changes. The carbon from CO2 combines with a five-carbon molecule, then splits into 2 x three-carbon molecules that continue along the cycle.
- NADPH molecules donate their hydrogen ions and electrons, and ATP molecules break into ADP + Pi to release energy for further changes to the carbon molecules.
- Carbon molecules continue to change and rearrange as they move around the cycle. Eventually one specific three-carbon molecule is created and leaves the cycle to contribute to the formation of glucose (six carbons). Overall, 6 CO2 must enter the cycle to produce glucose
- Some oxygens leftover from the breaking of the CO2 combine with hydrogen ions from NADPH to create water (output).
