Photosynthesis

Photo + Synthesis Photo = ? Synthesis = ? Works-LightDependent-Reactions-amp-Calvin-Cycle_620.jpg From its name, what do you think mean?

_web.gif _Photosynthesis-How-it-Works- LightDependent-Reactions-amp-Calvin- Cycle_620.jpg Guess the message of this slide

Are plants the only organisms that can carry out photosynthesis?

Science Golden Rule Law of Conservation of Energy – energy can neither be created nor destroyed, it can only be transformed from one state to another Q: Describe the energy transformation that takes place in photosynthesis.

Cellular Respiration vs Photosynthesis Oxygen, Carbon dioxide, Glucose, Water, ATP, Light 1. Choose words from the above list to write the word equation for cellular respiration. 2. Choose words from the above list to write the word equation for photosynthesis. 3. What do you notice?

Cellular Respiration vs Photosynthesis Cellular respiration Oxygen + Glucose  Carbon dioxide + Water + ATP Photosynthesis Carbon dioxide + Water + Light  Oxygen + Glucose (Chemical energy in organic compound) (Chemical energy ) (Chemical energy in organic compound) (Light energy)

Cellular Respiration vs Photosynthesis Cellular respiration 6 O 2 + C 6 H 12 O 6  6 CO H 2 O + ATP Photosynthesis 6 CO H 2 O + Light  6 O 2 + C 6 H 12 O 6

Light boa/Massama/photo htm What colour would you describe this light?

ow-too.jpg content/uploads/2007/12/cd-spinner-3.jpg A Spectrum of Colour

All come from white light

Light detectable by human eyes

Lightwaves, wavelength

How do we see colours?

How do we see colours? Red apple reflects red light and absorbs other colours

Light enters the eye, signals are sent to the brain, colours are interpreted

Visible light is only the waves the human eyes can see Infrared Ultraviolet X-ray Microwave

images/electromagnetic-spectrum.jpg

What colour does a leaf reflect? What colours does it absorb? Red apple reflects red light and absorbs other colours

3.8.3, Absorption Spectrum Chlorophyll

3.8.3 Chlorophyll as pigment

Absorption Spectrum Light absorbed by plants Action Spectrum Light used for photosynthesis

Details of Photosynthesis Many similarities to cellular respiration! Familiar terms: – H + (protons), electrons, NADP +, NADPH, electron transport chain, ATP, ADP, phosphates, ATP synthase, proton gradient, chemiosmosis – (Go revise cellular respiration first! You’ll feel more confident.)

synthesis.gif Q: How does plant obtain water?

Identify in this diagram Assessment Statements and Inside the chloroplast

Identify in this diagram Assessment Statements and Inside the chloroplast

8.2.1, organelles/organelles/chloroplast-b.gif

8.2.5 Light-independent Reaction/ Calvin Cycle 1.Carbon dioxide is "fixed" or attached to a 5-carbon sugar called ribulose biphosphate (RuBP) – by the enzyme ribulose biphosphate carboxylase (RuBisCo) 2.Produce a 6-carbon sugar similar to the sugar glucose. Each (unstable) 6 carbon molecules splits into 2 (3 Carbon compounds) known as Glycerate 3-phosphate (GP) which is an acid. 3.ATP and NADPH used to convert GP to sugar Triose Phosphate (TP, a.k.a. Glyceraldehyde 3-phosphate, G3P) 4.TP can be removed from the cycle and used for the formation of larger carbohydrates such as glucose, sucrose and starch. 5.3 RuBP is regenerated from the every 5 remaining TP. (3 x 5C = 5 x 3C)

(GP) = Triose Phosphate (TP)

Factors affecting rate of photosynthesis

3.8.8, Where have you seen a similar graph before?

3.8.8, Where have you seen a similar graph before?