Photosynthesis Flashcards
What is photosynthesis
The process in which CO2 and water is being turned into Glucose and Oxygen
Word equation for photosynthesis
CO2 + water –(sunlight)– Oxygen + Glucose
Balanced equation for photosynthesis
6CO2 + 6H2O –( sunlight)– C6H12O6 + 6O2
What are factors affecting the rate of photosynthesis
Light Intensity ( Can use artificial light sources in greenhouses)
Carbon dioxide cencentration (Burning natrual gasses in greenhouses)
Temperature ( emzymes in chorophyll)
Water
What is the importance of photosynthesis
Plants form the basis for our food chains and are primary producers.
One of the by-products of photosynthesis is oxygen, needed for respriation.
takes CO2 out of our atomsphere
The remains of plants, and the animals they supported are main components of fossil fuel
What are the two phases of photosynthsis
Light stage and dark stage
Describe the light stage breifly (and how its different for dark stage)
Not the process that take place, the stage itself
Light-dependent.Takes place during day. The presence of light is required for the reaction to proceed.
Describe the Dark stage breifly (and how different from light stage)
Not the process that take place, the stage itself
Reactions do not need light (occour independtly of the presence of light) Reactions are powered by ATP from the light stage. Needs electrons from light stage. Emzymes control the reactions,as a result, they are temperature dependent. Finally glucose is formed
What happends after choroplast is first absorbed in the leaves
(desribe what happends in the lightstage before either of the pathways)
Light shines on electrons in granum,electrons gain energy and become excited,electrons picked up by electrons acceptors
Explain pathway 1:cyclic
Electrons picked up by acceptors in the chlorophyll(high energy electrons).Electrons pass through evergy reactions (like electron transport system)Electrons therefore lose energy ( forms ATP from ADP + P, goes to dark stage) Electrons return to the chorophyll again)
Explain Pathway 2: Non-Cyclic
Electrons do not return to the chorophyll.
1.Water is split ( Photolysis)
-O2 is released ( atomsphere or internal respiration)
-H+ (or protons) go to proton pool.
-Electrons got to chlorophyll
2.Electrons picked up by acceptors and passed through energy reactions ( like Electron transport system)
3.Electrons then lose energy ( Forms ATP from ADP + P)
4.Electrons trapped by NADP+ to form NADP-. NADP- attracts protons forming NADPH (carries electrons and H+ to dark stage)
What are the products of the light stage and what are they used for
ATP supplies energy for dark stage reactions
NADPH supplies protons and electrons for dark stage reactions
Oxygen is used for respiration or released into the atomsphere
Explain Dark stage/Calvin Cycle
CO2 ( from atompherer or respiration) enters stroma of chloroplast.
ATP (from light stage) supplies energy
NADPH ( from light stage) supplies electrons and proton.
CO2 combines with( is reduced by) electrons and protons to form Glucose
ADP and NADP+ return to the light stage.
Investigate the influence of light intensity (or carbon dioxide) on the rate of photosynthesis.
Use pond weed (Elodea)
photosynthesise under water
Control other factors
Temperature- Monitered with Termometer (25 degrees)
CO2 - Add sodium bicarbonate (kept as excess)
H2o - Just there
Allow to rest beforecounting bubbles
to allow it to start photosynthesis at these conditions
How did you measure the rate of photosynthesis
Counting the number of O2 bubbles produces per min
The results of the influence of light intensity (or carbon dioxide) on the rate of photosynthesis.
As the light intensity is increased the rate of oxygen production increases. At a certain point an increase in light will not prompt an increase in the rate of photosynthesis. The plant is said to be saturated with light.
