Photosyntheis Flashcards
(13 cards)
Describe the structure of a chloroplast
Double membrane
Filled with stroma
Stroma contains stacks of Thylakoids with each stack being called a Granum
Where do the light-dependent reactions of photosynthesis take place
Thylakoids membrane
Where do the light - independent reactions of photosynthesis take place
In the stroma
What are the products of light dependent reactions in photosynthesis
Reduced NADP
ATP
What are the products of the light independent reactions in photosynthesis
6C sugars (hexose)
Describe the process of light dependent photosynthesis
1) light absorbed by PS 1 and PS 2 in the chlorophyll
2) electrons are boosted to a higher energy level
3) electrons emitted and passed to electron carriers
4) loss of electrons from PS 2 cause photolysis of water
5) water gives up electrons to PS 2, leaving oxygen (given off as waste) and H+ ions
6) electrons passed down electron carriers at successively lower energy
7) releasing energy to form ATP from ADP and Pi
8) electrons from PS 1 combine wit H+ and reduce NADP to NADPH
Describe the process of light independent photosynthesis
1) CO2 combines with RuBP (5C) to form a 6C
2) this is carbon fixation and it catalysed by RuBISCO
3) 6C breaks down into two GP (3C)
4) these are converted into GALP (3C) using energy from ATP and H+ ions from NADPH
5) majority of this is used to regenerate RuBP (5C)
6) some is used to produce 6C sugars such as glucose, amino acids, lipids etc.
How does climate change affect cause the balance in a community to shift
Some species may benefit from new conditions becoming dominant
Others will have to compete with existing or invading species
Species may migrate to an areas wth a more favourable climate
Higher temps in early part of the year may lead to longer growing periods
What are ‘alien invaders’
New species from different parts of the world
Include pests and disease which may reduce crop yields
Why would crop yields both increase and decrease with increasing temp
A few degrees of warming will lead to an increase in crop yield
But crop yields may be reduced due to lower rate of photosynthesis but also the rate at which enzymes work
What does temperature act as
An environmental trigger for changes in development or behaviour
How does egg incubation temp affect development in leatherback turtles
It influences the sex of the hatchlings, resulting in an uneven sex ratio
Define phenology
The study of seasonal events in the lives of animals and plants
