5.6.1-2(Relationship between photosynthesis and respiration and photosynthetic pigments)

Describe how photosynthesis and respiration are related

• They are both important is cycling CO2 and O2 in the atmosphere.

• The products of one process are the raw materials for the other.

• Aerobic respiratio removes O2 from the atmosphere and adds CO2

• Photosynthesis does the opposite

Describe what is meant by the compensation point of a plant

• It is the point in which the rate of respiration and photosynthesis are the same

• There is no net gain or loss of carbohydrate

Describe the structure of the chloroplasts

• Disc shaped membrane bound organelle

• Double membrane with an intermembrane space

• Outer membrane is highly permeable

• Contains a matrix - which contains stroma and grana

Describe the structure of the grana

• It is made of stacks of thylakoids

• Many thylakoids made a granum

  • A granum is connected to another by intergranal lamellae

How many thylakoids could 1 granum contain

• It can contain up to 100 thylakoids

Describe the adaptations which the chloroplasts have to their function

• Many grana

• Photosynthetic pigments

• Proteins imbedded in thylakoid membrane

• Fluid-filled stroma

• Grana surrounded by stroma

• Chloroplast DNA and ribosomes

Explain how many grana is an adaptation to chloroplasts

• Large surface area for absorption of light and photosystems

• Contains many ATP synthase

Explain how photosynthetic pigments are an adaptation to chloroplasts

• They are used to harvest light needed for photophosphorylation

• Funnelled down to the reaction centre

Explain how proteins being embedded in thylakoid membranes is an adaptation to chloroplasts

• Allows and contains photosystems, electron transport chain and ATP synthase

Explain how the fluid filled stroma is an adaptation of chloroplasts

• Contains enzymes for calvin cycle(LIR)

• Conatins starch grains, DNA and ribosomes

Explain how the grana being surrounded by stroma is an adaptation of chloroplasts

• Allows for the movements of products from LDR to move to the LIR

Explain how chloroplast DNA and ribosomes are an adaptation of chloroplasts

• Allows for the production of enzymes used in the LIR by using protein synthesis

Describe what is meant by photosynthetic pigments

• They are pigments located in each thylakoid’s photosystem

• Photosynthetic pigments absorb certain wavelengths of light

• The colours which are reflected are the colours which we see

Describe how different wavelengths are captured by chloroplasts

• Different pigments absorb a particular wavelength of light

• The energy associated with the wavelength of light is captured and funnelled down to the primary pigment reaction centre - consisting of a certain chlorophyll at the base of the photosystem

Name the 2 types of chlorophyll

• Chlorophyll a

• Chlorophyll b

Describe the structure of chlorophylls

• They are a mixture of pigments

• They all have similar molecular structure

  • contain a porphyrin group which is in a magnesium atom and a long hydrocarbon chain

What wave lengths does chlorophyll a absorb

• Absorbs red light a wavelengths 680 - 700nm

• Absorbs some blue light at 440nm

What wave lengths does chlorophyll b absorb

• Absorbs wavelengths 400-500nm

• Absorbs wavelengths at 640nm as well

What is the pigment colour and rf value for each pigment

• Carotene - orange yellow: 0.96

• Phaeophytin - grey: 0.63-0.75

• chlorophyll a - blue green: 0.58

• chlorophyll b - green: 0.48

• Xanthophyll - deep yellow: 0.44