220 likes | 369 Vues
Photosynthesis. Why does a leaf look green ?. How much of the light absorbed is used ? . Absorption spectrum of chlorophyll. Structure of a chloroplast. thylakoid. ( thylakoids stacked like pancakes ). Light- dependent reactions : First stage of photosynthesis.
E N D
Structure of a chloroplast thylakoid (thylakoidsstackedlikepancakes)
Light-dependentreactions: Firststage of photosynthesis • Photolysis of water: energy absorbed bychlorophyllisusedtosplitwatermoleculesintohydrogen and oxygen. • Oxygenisreleased as a wasteproduct. • ATP isproducedduetophotolysis.
Light-independentreactionsSecondstage of photosynthesis • Alsoknown as Calvin cycle • Carbondioxideis absorbed to produce glucose. • Theconvertionfrom gas toorganicmoleculesiscalledcarbonfixation. • Hydrogenrelease in photolysis and ATP are used in thissecondstageto produce glucose.
Tosum up • Whatdoesphotolysis mean? • When and wheredoesitoccur? • Whatisconsidered a wasteproduct in light-dependentreactions? • Forwhatproductiscarbondioxide absorbed? • Whatiscarbonfixation?
plateau CO2 is a substrate in an enyme-catalysed light-dependent reaction. At low CO2 concentration, rate is positively correlated with concentration
plateau At low light intensity, rate of photosynthesis is proportional to light intensity.
Optimum temperature Above the optimum temp., enzymes are denatured and rate drops steeply. Increased temp. gives increased energy and increased rate of photosynthesis Which enzymes are used in respiration?
What are the conditions of each of these trials? Rate of photosynthesis Light intensity
What is the importance (for all living organisms) the process of photosynthesis? What is the most convenient method to measure photosynthesis? What factors must be consider when you measure photosynthesis? When a process is influenced by several factors which one determines the rate at which the process proceeds? What organic molecule is produce and what gas is given off during photosynthesis? What are the two main groups of photosynthesis pigments? What is the best wavelength for absorption? Photosynthesis