Photosynthesis Flashcards
Anabolism
when small molecues are converted into larger molecules - resquires energy in the form of ATP
Is ATP high or low energy
High energy
light dependent
light must be present
What does NADP+ stand for
nicotinamide adnine dinucleotide phosphate
photolysis
splitting of water by light into 2H+, 2e- and 1/2 O2
Autotroph
a living organism that has the ability to make its own food
what is photosynthsis
the process in which co2 and water is being turned into glucose and oxygen
Balanced equation for photosynthesis
6CO2 + 6H2O –( sunlight)– C6H12O6 + 6O2
Where do plants get their source of CO2
animal and plant respiration, burning of fossil fuels
where do plants get their water
soil(enters root via osmosis)
where is chlorophyll found
in chloroplast
what is the glucose used for in photosynthesus
energy for chemica reactions
What is the fate of the oxygen produced
released into atomsphere via stomata/lenticles or used in internal respiration by plant
What is the role of phtotsynthesis
plants form basis of our food chain- primary producers.
take CO2 out of atomsphere
O2 produced needed for respiration.
the remains of plants, and the animals they supported, are the main componets of fossil fules
How can photosynthesis be artificially enhanced
burning gas in greenhouse, produce carbon dioxie
artificial light sources
Increasing the temperture
What are the two stages of phtotsynthesis
Light Stage
Dark Stage
Where does the light stage occour
Granum of chloroplast
Where does the dark stage occour
Stroma of chloroplast
What are the two pathways that the light stage is divided into
Cyclic and Non-Cyclic
Describe cyclic phosphorylation
Light shines on electrons in granum. The electrons gain energy and become excited. The electrons are passed though acceptors which cause the electron to lose energy. This energy is used to turn ADP + P into ATP. The low energy electrons return to original Granum
Describe non cyclic phosphorylation
Light shines on electrons in granum. Electrons gain energy and become excited.
The electrons are passed though acceptors which cause the electron to lose energy. This energy is used to turn ADP + P into ATP. Water is split when light hits it (Photolysis) into 2e- and 2H+. NADP+ joins with the two low energy electrons and two H+ ions to form NADPH (to dark stage) The newly formed electrons return to a different granum
What are the products of the light stage and what are they used for?
O2 (waste, released into atomsphere or used in internal respiration)
ATP ( supplies energy to dark stage)
NADPH (supplies 2H+ ions and 2e- to dark stage)
What is the dark stage controlled by?
Enzymes
Describe the dark stage
CO2 (from atomsphere or respiration) enters stroma of chloroplast.
ATP supplies energy (from light stage)
NADPH supplies 2H+ and 2e- (from light stage)
CO2 combined with electrons and Hydrogen Ions to form glucose
ADP + P and NADP+ return to light stage
Factors that affect the rate of photosynthesis
Light intensity
CO2 concentration
Temperture
Describe how you invetigated the effect of light intensity on the rate of photosynthesis
Used Elodea pond weed (photosynthesis under water, we can count the O2 bubbles produced.
Cut stem underwater at an angle
Controlled other factors by:
-temperture (placing thermometer in temperture controlled water bath @25 optimun)
-CO2 conc (kept in excess by adding sodium bocarbonate)
vary light intensity by moving lamp
Allow to rest before counting bubbles to Allow it to start photosynthesis at these conditions ensure accuracy
Measure rate of photosynthesis by counting the no. of O2 bubbles produced per min
What is Saturation point
as light intensity increases, the rate of photosynthesis increased up to a certain point. at this point, an increase in light intensity will not prompt an increase in the rate of phtotsynthesis. This point is called the saturation point
