Photosynthesis Flashcards
1
Q
What is an autotrophic and heterotrophic organism?
A
- Autotrophic
- organism that photosynthesise
- use sunlight to build complex organic molecules
- heterotropic
- obtain complex organic molc by eating other organisms
2
Q
Why do chloroplasts contain a netowrk of membranes?
A
- provide a large SA to maximise the absorbtion of light
- essential in the first step of photosyntheises
3
Q
What features do the membranes form?
A
- membrane form flattened sacs called thylakoids
- thylakoids are stacked to form grana
- the grana are joined by membranous channels called lamellae
4
Q
Where is light absorbed?
A
- complexes of pigments
- such as chlorophull
- embedded within thylakoid membranes
5
Q
What is the fluid enclosed in the chloroplast and what is its function?
A
- site of many chemical reactions
- resulting in the formation of complex organic molecules
6
Q
What do pigment molecules do?
A
- absorb specific wavelengths of light and reflect other
- different pigments absorb and reflect different wavelength
- why they have differences in colour
7
Q
What is the primary pigment in photosynthesis and what does it absorb and reflect?
A
- chlorophyll a
- absorbs
- red
- blue
- reflects
- green
- reason for green plants
8
Q
What are the accessory pigments and what is their function?
A
- chlorophyll b
- xanthophylls
- cartenoids
- absorbs different wavelengths of light than those absorbed by chlorophyll a
- causes different shades of leaves
9
Q
What is the antennae complex
A
- accessory pigments embeeded in thylakoid membrane of the chlorplast
- these and other proteins and pigments form a light harvesting system
- aka antennae complex
10
Q
What is the role of the antennae complex?
A
- role of the system is to absorb light energy of different wavelengths and transfer this energy quickly and efficiently to the reaction centre
11
Q
What is the reaction centre?
A
- chlorophull a is located in the reaction centre
- which is where the reaction involved in photosynthesis takes place
- contains the primary pigment only
12
Q
How are photosynthetic pigments investigated?
A
- chromotography
- seperate pigments in a plant extract
- mobile phase would be the soln containing the mixture of pigments
- stationary phase a thin layer of silica of gel applied to glass
- different interaction with the stationary phase and different solubilities in mobile phase lead to moving at different rates
13
Q
What is the retention value?
A
- Rf value cna be calculated using the formula
- distance travalled by component / distance travelled by solvents
14
Q
Explain shape of both curves
A
- photosynthwaia
- increased photosynthetic activity during the day
- increase activity of LDR
- respiration
- slihg increase during day because enzyme controlled reaction are temp dependant
15
Q
What is the chlroplast envelope
A
double membrane of the chloroplast
