5A

Question 1

What is photosynthesis

Answer 1

a series of chemical reactions that occurs in producers

Question 2

What is the equation of photosynthesis

Answer 2

6CO2+ 6H2O= C6H12O6 + 6O2

Question 3

Where is the energy stored

Answer 3

Within the bonds in glucose molecules

Question 4

Where does the energy required to form ATP comes from

Answer 4

By electron transport chain which is the passage of electrons in a series of Redox reactions

Question 5

Where does photosynthesis (light-dependent reaction) occur in the plants cell

Answer 5

in thylakoid membrane

Question 6

What is coenzyme

Answer 6

A non-protein molecule that helps an enzyme carry out its function but is not used in the reaction itself

Question 7

What is NADP

Answer 7

It’s a coenzyme that transfers hydrogen from one molecule to another

Question 8

State the name and color of chlorophyll molecules pigment

Answer 8

Chlorophyll a (blue-green)
Chlorophyll b (yellow-green)
Chlorophyll carotenoids ( orange carotene and yellow xanthophyll)
Grey pigment phaeophytin

Question 9

what are the two types of photophosphorylation

Answer 9

-Non-cyclic: produces both ATP and NADPH
-cyclic : produces ATP only

Question 10

what is common between cyclic and non-cyclic

Answer 10

-A series of membrane proteins which together make up the electron transport chain
-Chemiosmosis
The energy released as electrons pass down the electron transport chain is used to produce ATP

Question 11

what are photosystem I and photosystem II

Answer 11

a combination of chlorophyll pigments which absorbs light of wavelength (for I 700nm II 680) and is involved in cyclic and non-cyclic photophosphorylation

Question 12

State the steps in non-cyclic photophosphorylation

Answer 12

-light energy hits photosystem II in thylakoid membrane
-Two electrons gain energy and get excited to a higher levels of energy
-they lose energy as they leave photosystem II and are replaced by electrons from the photolysis of water
- energy is released when electrons pass down electron transport chain and is used by chemiosmosis
- electrons leave photosystem II and pass through photosystem I
- light energy hits photosystem I to excite electrons and leave then pass through ETC
- these electrons combine with hydrogen ions from photolysis of water and NADP to produce NADPH

Question 13

What does light-independent reaction require

Answer 13

ATP and NADPH

Question 14

State the steps of cyclic photophosphrylation

Answer 14

1. Light hits photosystem l
2. electrons are excited to a higher energy level and leave the photosystem
3. The excited electron pass along the ETC releasing energy as they do so
4. The energy released as electrons pass down is used to drive the process chemiosmosis
5. The electrons rejoin photosystem 1
6. The ATP produced enters the light-independent reaction

Question 15

Describe the events of chemiosmosis

Answer 15

Hydrogen ions are actively pumped to a higher concentration inside the thylakoid membrane generating a concentration gradient across the thylakoid membrane,
Hydrogen ions diffuse back to stroma through ATP synthase
The movement of hydrogen ions causes ATP synthase to catalyse the production of ATP

Question 16

what are the complex compounds that independent-reaction allows to be produced

Answer 16

Starch for storage
Sucrose for transport
Cellulose for making cell walls

Question 17

what are the three main steps for independent reaction

Answer 17

1. Carbon dioxide is combined with ribulose bisphosphate (RuBP) by rubisco ; this yields two molecules of glycerate 3-phosphate (GP)
2. GP is reduced to glyceraldehyde 3-phosphate (GALP) in a reaction involving reduced NADP and ATP
3. RuBP is regenerated from GALP in reactions that use ATP

Question 18

what happens when carbon dioxide and RuBP combine

Answer 18

carbon dioxide and RuBP combine by enzyme rubisco
The resulting 6-carbon (6C) compound is unstable and splits in two
This results in two molecules of a 3C compound known as glycerate 3-
phosphate (GP)
the carbon dioxide is fixed which mean that it is removed form external enviroment and turned into a molecule inside the plant

Question 19

reducing GALP

Answer 19

ATP and reduced NADP are used to reduce GP into GALP
some of carbon in GALP are used to produce useful molecules while the rest is used for regenration of RuBP

Question 20

how is GALP used to produce hexose sugars

Answer 20

-by making glucose which is involved in respiration to produce ATP
- converting hexose sugars to different hexose sugars
-hexose sugars can be joined to make polysaccharides

Question 21

what is the function of the structure of chloroplast

Answer 21

• chloroplast envelope: it encloses the chloroplast so the structure are close to each other and its inner membrane controls the flow of molecules
  -stroma: the fluid that contains the enzymes
  -DNA : contains genes that code for some proteins
  -ribosomes: they enable the translation of proteins coded by DNA
  -thylakoid membrane: contains the thylakoid space that establishes the concentration gradient of protons
• grana: creates a large surface area and allows a maximum light absropion
• photosystem : contain different pigement which allow maximum light absorption