Photosynthesis Flashcards
What is the structure of the chloroplast?
Has three membranes. The inner, outer and thylakoid membrane. The thylakoids are in stacks called granum in the stroma.
Where do light reactions occurs?
On the thylakoid membrane
Where does carbon fixation/ Calvins cycle occur?
In the stroma.
What are photosystems?
Protein complexes that contain chlorophyll
How do photosystems capture light energy?
Chlorophyll absorbs light energy, Light energy absorbed by colour produces high energy electrons. High energy electrons travel through the photosynthetic electron transport chain.
What do photosystem 1 and 2 do?
The protein complexes gather high energy electrons from light energy absorbed through chlorophyll. These electrons are then used to make NADPH.
What is the photosynthetic electrons transport chain?
First stage of photosynthesis. A series of molecules that accept or donate electrons easily. By moving in a step by step movement, the electrons are moved in a specific direction across the membrane. The movement of hydrogen ions is coupled with this, as electrons are moved, hydrogen ions are moved as well.
How is ATP made in the photosynthetic electron transfer chain?
When the hydrogen ions that have formed a concentration gradient are pumped into the lumen of the thylakoid membrane through ATP synthase. By moving through ATP synthase they give power to the reaction ADP + Pi = ATP.
What is the path the electrons move through in the photosynthetic electron transport chain?
Photosystem 2 - Cytochrome complex - Photosystem 1 - converted into NADPH (for use later in the Calvin cycle)
Where does water get split into 1/2 O2 and 2H+?
In photosystem 2
What does electron transport help to establish?
A concentration gradients of hydrogen ions.
What happens in the Calvin cycle?
Takes 3CO2 and produces a 3 carbon sugar which then goes on to make glucose and other compounds. The reactions of ATP to ADP and NADPH to NADP+ provides energy from the bonds to drive this process.
Where is glucose made in photosynthesis used?
Plant cells break down glucose from photosynthesis in the mitochondria using cellular respiration. Don’t use ATP and NADPH directly in the cell as a source of energy, this is only used to power the Calvin cycle.
What are the similarities and difference in animals and plants when it comes to respiration/ photosynthesis?
Both animals and plants breakdown glucose in cellular respiration. Animals get glucose from an outside source (eating) whereas plants get glucose from converting light energy in photosynthesis.
What is theory of the origin of chloroplasts and mitochondria?
Both contain DNA and ribosomes and are able to make some proteins, so was thought to be independant at some time. If cells have a decent cytoskeleton they can engulf other organisms. One cell engulfed a much small cell (prokaryotic) that was able to break down sugars using oxygen. Instead of being digested it was stable and it stayed in the cell, forming a symbiotic relationship.
