Download Section 3.3 - Photosynthesis

Section 3.3 - Photosynthesis

Photosynthesis uses __________________________________ from the sun to fix
________________________ into _______________________________ (namely glucose).

The captured radiant energy is stored within the _______________ of the carbohydrate as chemical energy

Photosynthesis is used by many autotrophs to make their own food
o egs. vascular plants, algae, cyanobacteria
Write the net equation for photosynthesis below in words and in chemical formulas (pg. 83 of your text)
Photosynthesis and Cellular Respiration appear to be ___________________________________ , but they use
very different ______________________________.
The processes are similar in that both use:
1. _______________________________________________
2. _______________________________________________
3. _______________________________________________



Plants are made of various types of tissues
o egs. Stem, leaves, roots, reproductive organs
The main site of photosynthesis is the ____________, although chloroplasts are found in all green plant parts
Stamata (singular =stomate) are pores on the underside of leaves which allow for gas exchange. To conserve
water, these can be opened and closed
Opening the Stomata
Closing the Stomata
The Structure of the Chloroplasts
Zoomed in on Granna:
Stages of Photosynthesis
Photosynthesis is divided into two stages:
1. Light dependent reactions (light reactions)
Uses sun’s energy to produce:
Don’t be fooled!!!
2.
Light independent reactions (dark reactions)
Uses stored chemical energy to produce
The Electromagnetic Spectrum
The full range of wavelengths of light emitted from
the sun is known as the electromagnetic spectrum
Visible light is between ______________________.
Light has properties of both waves and particles
Light travels in bundles of energy called ___________.
The energy from photons is used to initiate
photosynthesis.
Photosynthetic pigments absorb light
 Each pigment can absorb light (photons) within a specific range of _________________________
 Wavelengths that are not absorbed are said to be ____________________ or reflected
◦ This is the light we see determines what colour we see
 The most common pigments in plants are ________________________ and _________________________
◦ What colours are absorbed?
______________________ (optimal @ 400-450nm)
What colours are reflected?
______________________ (optimal @650-700nm)
_________________________________
Photosystems
Where do the light dependent reactions take place?
____________________________________________________________________________________________
 Groups of molecules responsible for the light dependent reactions are called photosystems
 Each photosystem has:
1. _______________________________________
•
200-400 _________________________ molecules, accessory pigments (ex. carotenoids)
2. _______________________________________
•
a specialized _______________________ molecule with associated proteins
3. _______________________________________

There are 2 photosystems in plants:
o Photosystem I (PS I) & Photosystem II (PS II)
o Other names (used by text)
 PS I absorbs best at ________________; called _______________
 PS II absorbs best at ________________; called _______________
How Photosystems Capture Light Energy:
1. ______________ of light are absorbed by antenna pigments causing them to move from
_________________________ to an __________________________.
2. “Excitation” energy is passed along chlorophyll molecules until it reaches the __________________________.
3.
_______________________________ in the reaction centre absorbs the energy.
4. The high-energy state of chlorophyll a causes it to ______________________________.
5. The __________________________________________________ takes the electrons from chlorophyll a
 this process is called ___________________________________.
Howework
Read Section 3.3 up to “The Calvin Cycle”
1) Do section review 1-4 on pg. 94
2) Explain the difference between the cyclic and non-cyclic pathway