1. A2 PHOTOSYNTHESIS L1 Introduction, Chloroplasts and Light Spectra Pp299-300

2. A2 PHOTOSYNTHESIS PHS1 Intro, chloroplasts, spectra PHS2 Chromatography of pigments PHS3 The light dependent reactions PHS4 The Dark Reactions / Calvin Cycle PHS 5 and 6 Hill Reaction Practical PHS 7 Products of photosynthesis, chemiosmosis, Mineral nutrients

3. L1 Introduction, Chloroplasts and light Spectra 1.Define the term ‘photosynthesis’. 2.The main site of photosynthesis in the leaf is palisade tissue. 3.The ultra-structure of chloroplasts: Label the structures 4.Interpret Englemanns experiments in terms of ‘absorption spectra’ and ‘action spectra’

4. Key Words PHS1 & 2 Chlorophylls a & b Absorption spectrum / spectra Action spectrum Carotenoids Xanthophylls Primary and accessory pigments Granum/ grana Thylakoid Stroma Rf value Solvent front

5. Photosynth https://www.youtube.com/watch?v=g78utc LQrJ4https://www.youtube.com/watch?v=g78utc LQrJ4 Respiration https://www.youtube.com/watch?v=0IJMR sTcwcghttps://www.youtube.com/watch?v=0IJMR sTcwcg

6. Photosynthesis Two-stage process Light-dependent reaction –Occurs only during daylight Light-independent reaction –May continue in the dark

7. Evidence for two stages Temperature has a clear effect on the rate of photosynthesis –This suggests that although light levels initially limit the rate, there is a second stage controlled by temperature-sensitive enzymes A plant given alternating periods of dark and light forms more carbohydrate than one in continuous light –Period of darkness ensures that all the product from first stage is converted into carbohydrate before it builds up

8. 1. Define photosynthesis “Photosynthesis uses light energy to synthesize organic molecules.” What are organic molecules? “Chloroplasts are transducers, converting the energy of light photons into the chemical energy of ATP.” What are transducers? What are photons?

9. 2. The main site of photosynthesis in the leaf is palisade tissue. Find a page reference for this in your text book

12. 3. The ultra-structure of chloroplasts: Label the structures 1.Copy this diagram quickly 2.What re the underlined bits for? 3.Complete: ____ are stacked _____ linked by _______. They contain _______ 4.Measure the length of your picture. Chloroplasts are 5µm long. What is your drawings’ magnification?

14. For the magnification – remember I AM in the triangle: I A M

16. Photosynthesis Two-stage process Light-dependent reaction –Occurs only during daylight

17. Excitation of electrons Photon of light hits chlorophyll molecule Energy transferred to the electrons in the molecule Electrons raised to higher energy levels If they are raised to a high enough level they will dissociate Electrons picked up by an electron acceptor ATP formed as the electron is passed along an electron transport chain

18. Basic Physics of light Electromagnetic spectrum Wavelength and frequency Red, green & blue are _____ colours White objects reflect R,G and B. Wavelength of red light = 620-720 nm Wavelength of green light = 495-570 nm Wavelength of blue light = 450-495 nm Which wavelengths do green leaves absorb and reflect?

19. hannah.taylor@lansdownecollege.com

24. Homework Q 6 p 309 Use p300 to help you