Photo Synthesis

Question 1

What is the Chemical Equation for Photosynthesis

Answer 1

6(H2O)+6(CO2)–>(C6)(H12)(O6)+6(O2)

Question 2

What does the organelle chloroplast look like and where are the Ganum and Stroma?

Answer 2

The organelle looks like a leaf, with the Granum being the darker bits within the stem while the stroma is the space between the stems.

Question 3

What are the inputs of the light-dependent reaction?

Answer 3

H20, ADP+Pi, NADP

Question 4

What are the outputs of the light-dependent reaction?

Answer 4

O2 (released to the atmosphere), ATP and NADPH (used in the light-independent reaction)

Question 5

What is the site for photosynthesis?

Answer 5

Thylakoids

Question 6

Why is Carbon dioxide a factor that will affect the rate of photosynthesis?

Answer 6

It increases the reaction rate because carbon is incorporated into the carbohydrate in the light-dependent reaction. Though it is limited by atmospheric concentration therefore limiting the maximum rate or reaction.

Question 7

What is the purpose of photosynthesis?

Answer 7

Photosynthesis is an anabolic chemical reaction in which the Sun’s light energy is used to convert inorganic compounds carbon dioxide and water into organic compound glucose. Therefore light energy is converted to chemical energy and stored in the bonds of glucose.

Question 8

What is the Stroma?

Answer 8

This is the site of the light-independent (Calvin cycle) reaction, a fluid-filled space that surrounds the grana.

Question 9

What is Granum?

Answer 9

This is a stack of thylakoid membranes inside the stroma inside the chloroplast of the plant and algae cells. This is where the LDR takes place.

Question 10

What is a thylakoid membrane?

Answer 10

The site of the light-dependent reaction contains chlorophyll. Chlorophyll sits on the surface of each thylakoid.

Question 11

What is the light-dependent reaction?

Answer 11

This occurs in the thylakoid membranes of the GRANA in chloroplasts usually in mesophyll cells. It is when light is absorbed by the chlorophyll, thus this causes water to split into oxygen and hydrogen ions as a results of this electrons will also be released. Then the coenzyme NADP+ pick up a hydrogen ion and transfers it to the LIR. During the process the ADP+ inorganic phosphate are abeing converted to ATP vix electrons and oxygen is diffused out of grana and released via the open stomata.

Question 12

What does glucose do?

Answer 12

The glucose produced can be used as a source of energy by cells, enabling growth and reproduction.

Question 13

What is chlorophyll?

Answer 13

The green pigment in the thylakoid membranes of the chloroplasts of green plants, the chlorophyll absorbs light energy for photosynthesis.

Question 14

What are the inputs and outputs of LIR.

Answer 14

CO2, NADPH and ATP, the outputs are glucose NADP+ and ATP+Pi

Question 15

Which colours are best absorbed?

Answer 15

Red and blue wavelengths of light are absorbed the most green is absorbed the least.

Question 16

What coenzymes are involved in photosynthesis?

Answer 16

ATP carries energy between LDR and LIR and NADPH which moves electrons and protons between LDR and LIR.

Question 17

What is Rubisco?

Answer 17

The role of Rubisco within photosynthesis is to maximise the efficiency of photosynthesis, Rubisco is in the stroma and is used to catalyse the carbon fixation in the LIR.

Question 18

What are the enzymes for photosynthesis?

Answer 18

For photosynthesis the enzyme is Rubicso.

Question 19

What do pyruvate do?

Answer 19

This is when you split glucose, essentially glucose is 6 carbon molecules and then during cellular respiration it gets split up into 3 carbon molecules called pyruvate, this happens in both anerobic and aerobic , this is part of a process called glycolysis.

Question 20

What is the light-dependent process?

Answer 20

The LDR process happens within the stroma of the chloroplast, the carbon dioxide enters the Calvin cycle for C3 plants whereas for C4 and CAM plants they are converted to malate first, then converted back to CO2 for use in the Calvin cycle, then the unloaded carriers (NADP+ and ADP+Pi) return to the LDR to pick up more hydrogen and electrons, RuBisco is needed to catalyse the first reaction.

Question 21

Why would water affect the rate of photosynthesis?

Answer 21

This is limited by water avaliability in soil therefore this limits the maximum rate of reaction as an input in the LDR.

Question 22

Why does temperature affect photosynthesis?

Answer 22

This affects the enzymes that facilitate the reaction, if the temperature is too low this will slow the reaction rate and if its too high the enzyme will denature.

Question 23

How does light avaliabiltiy affect photosynthesis?

Answer 23

This affects the rate of LDR and is linked to temperature and water avaliability.Increasing the light intensity also increases the rate of photosynthesis untill all the active sites are full thus causing it to go into a state of plateu.

Question 24

What is the light independent reaction?

Answer 24

C3 basic bitches they do nothing, they take the laoded carries from the LDR and move it from the Garnum to the stroma, they immediately undergo the process of calvin cycle to produce glucose. They happen simoutaniously when light is avaliable. The major flaw is it relys on amtpsphere c02 concentration, therefore in high temeprature C3 plants undergo a lot of photorespirition. C4 the loaded carries happen in the mesophyll, the first stage of carbon fixation occurs in the mesophyll cell this invovles turning C02 in malate, then the malte and loaded carries are moved in the bundle sheath cells, then they undego calvin cycle as normal. Even in low C02 concentration enviroments they can still undergo photosythesis. CAM carbon fixation happens as night when stomata is open, during the morning when it is cool stored malate is used in the light independent stage because of this CAM plants grow slowely but the rate of photosyntehsis is not as affected by C02 concentration levels or water concentration. CAM plants are most suited to hot and arid conditions. Limits photorespiration and water loss.

Question 25

What are some limiting factors of photosynthesis?

Answer 25

Light intensity, water avaliability, atmosphere C02 concentration. The limiting factor is required to undergo photosynthesis and an increase in a limiting factor collraltes in the increase of photosynthesis up untill a certain point then it plateus because something else become a limiting factor.