1 Flashcards
What type of membrane does the chloroplast have
Double membrane
What structure links the grana
Lamellae
What is found within the stroma
Starch and enzymes
Where does the light dependant stage of photosynthesis take place
In the thylakoid membrane
Where does the light independent stage take place
Stroma
What structural features of thylakoids increase rate of photosynthesis
Arranged in stacks called grana which increase surface area to maximise absorption of light
What is found within the inner chloroplast
Many membrane bound electron transport proteins to control the passage of substances in and out
Describe outer chloroplast membrane
Permeable to small molecules such as water and oxygen
What is a thylakoids disc
A system of interconnected, flatted fluid filled sac with proteins embedded in the membrane
What is the function of the starch grain
Stores the product of photosynthesis
Describe the stroma
Gel like fluid outside the thylakoids and contains enzymes and sugar and other molecules needed for the light independent stage
Why do thylakoids have large surface area
To absorb as much light energy as possible
What is the function of the stroma
Fluid filled matrix in the chloroplast which contains enzymes used for the light independent stage
What is the function of the thylakoids space
Contains photosynthetic pigments and enzymes needed for light dependant reaction
Why are lots of ATP Synthase enzymes present in the thylakoids membranes
To produce ATP in the light dependant reaction
What is a photosynthetic pigment
Molecules that absorb light energy needed for photosynthesis
Where are photosynthetic pigments found
In the thylakoids membrane
How are photosynthetic pigments arranged
Into photosystems
What is the main photosynthetic pigments
Chlorophyll A
Why do photosystems contain accessory pigments
To absorb different wavelengths of light and maximise the amount of light captured
Why does chlorophyll appear green
Because it absorbs light at two wavelengths 430nm and 662nm and reflects green light
Why is it important to use an organic solvent and not a polar one
A polar solvent could compete with the dissolved molecules for space on the stationary phase and could cause them to move further away resulting in an inaccurate Rf value
Why is it important to mark in pencil rather than pen
Ink can dissolve in the solvent and move up the stationary phase and the colours could affect the results, furthermore there would be no start line to measure the Rf value
Why is it important that the spit of plant extract is above the surface of the solvent when the chromatography plate is placed in the vial
To ensure the pigments are carried up by the solvent and don’t dissolve into the solvent
Why is repeated application of the plant extract onto the same spot required
To increase the concentration of the pigment
Why is it important that the chromatogram is stopped before the solvent reaches the top
So the distance travelled can be identified and drawn which are needed to calculate Rf value
Why is it important to mark the solvent front quickly
The solvent is volatile and will evaporate quickly, once it is dry it cannot be seen
Why is it useful to mark the postitions of the pigment spots or take photograph of the chromatogram zoom after the run
Light can cause them to fade
