Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
13 Cards in this Set
- Front
- Back
|
What is an autotroph? |
An organism which obtains its food from light energy |
|
|
What is a heterotroph? |
An organism which only feeds on autotrophs. |
|
|
What is light energy converted into in photosynthesis? |
Chemical energy |
|
|
What is the balanced equation for photosynthesis? |
6CO2 + 6H2O --> 6O2 + C6H12O6 |
|
|
Explain the light dependent reaction: |
1 - light energy absorbed by a light harvesting system called PSII. This causes the electrons to become excited rating them to a higher energy level. The two electrons and then passed down and electron transport chain. As they are passed down the chain they lose energy. 2 - this energy causes Hydrogen ions to be pumped into the thylakoid by a proton pump. This maintains a hydrogen ion concentration gradient however the hydrogen ion concentration gradient is higher in the thylakoid down the stroma. 3 - this causes a hydrogen ions to diffuse through ATP synthase. This combines ADP and inorganic phosphate producing ATP. 4 - at the end of the electron transport chain the electrons are transferred to PSI. Here they are combined with hydrogen ions and NADP to produce reduced NADP |
|
|
how is light harvested in a photosystem? |
The light energy is absorbed by accessory pigments . These accessory pigments are chlorophyll b, xanthrophyll and carotene. The light energy is passed from pigment to pigment until it reaches the reaction centre of the primary pigment chlorophyll a. The electrons become excited and they are raise to a high energy level. accessory pigments allow a range of wavelengths to be absorbed. |
|
|
What is cyclic phosphorylation? |
Cyclic Phosphorylation is when the electrons after being passed down the electron transport chain are returned to photosystemII therefore only ATP is produced. |
|
|
What are the advantages of a chloroplast having thylakoids and DNA? |
The thylakoid have a large surface area to absorb the maximum amount of light energy and to have a greater number of electron carriers and ATP synthase. DNA codes for the enzymes and proteins needed for photosynthesis. |
|
|
Explain the light independent reaction: |
1 - RuBP combines with six molecules of carbon dioxide to form two molecules of GP with the reaction catalysed by RUBISCO. 2 - the two molecules of GP are reduced to TP by the addition of the coenzyme and NADPH using ATP. 3 - TP then combines with ATP to regenerate RuBP. 4 - 1/6 TP molecules form a hexose sugar. |
|
|
What organic products can TP make? |
TP can make carbohydrates, lipids as glycerol is synthesised from TP and the fatty acids our synthesised from GP and some amino acids can also be made from GP. |
|
|
What factors affect photosynthesis? |
Temperature, light intensity, carbon dioxide concentration and temperature with carbon dioxide concentration |
|
|
What are the products produced in the light independent reaction? |
Hexose sugar, NADP and ADP |
|
|
What are the products produced in the light dependent reaction? |
Oxygen, ATP and reduced NADP |
