5A Flashcards
(21 cards)
What is photosynthesis
a series of chemical reactions that occurs in producers
What is the equation of photosynthesis
6CO2+ 6H2O= C6H12O6 + 6O2
Where is the energy stored
Within the bonds in glucose molecules
Where does the energy required to form ATP comes from
By electron transport chain which is the passage of electrons in a series of Redox reactions
Where does photosynthesis (light-dependent reaction) occur in the plants cell
in thylakoid membrane
What is coenzyme
A non-protein molecule that helps an enzyme carry out its function but is not used in the reaction itself
What is NADP
It’s a coenzyme that transfers hydrogen from one molecule to another
State the name and color of chlorophyll molecules pigment
Chlorophyll a (blue-green)
Chlorophyll b (yellow-green)
Chlorophyll carotenoids ( orange carotene and yellow xanthophyll)
Grey pigment phaeophytin
what are the two types of photophosphorylation
-Non-cyclic: produces both ATP and NADPH
-cyclic : produces ATP only
what is common between cyclic and non-cyclic
-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
what are photosystem I and photosystem II
a combination of chlorophyll pigments which absorbs light of wavelength (for I 700nm II 680) and is involved in cyclic and non-cyclic photophosphorylation
State the steps in non-cyclic photophosphorylation
-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
What does light-independent reaction require
ATP and NADPH
State the steps of cyclic photophosphrylation
- Light hits photosystem l
- electrons are excited to a higher energy level and leave the photosystem
- The excited electron pass along the ETC releasing energy as they do so
- The energy released as electrons pass down is used to drive the process chemiosmosis
- The electrons rejoin photosystem 1
- The ATP produced enters the light-independent reaction
Describe the events of chemiosmosis
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
what are the complex compounds that independent-reaction allows to be produced
Starch for storage
Sucrose for transport
Cellulose for making cell walls
what are the three main steps for independent reaction
- Carbon dioxide is combined with ribulose bisphosphate (RuBP) by rubisco ; this yields two molecules of glycerate 3-phosphate (GP)
- GP is reduced to glyceraldehyde 3-phosphate (GALP) in a reaction involving reduced NADP and ATP
- RuBP is regenerated from GALP in reactions that use ATP
what happens when carbon dioxide and RuBP combine
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
reducing GALP
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
how is GALP used to produce hexose sugars
-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
what is the function of the structure of chloroplast
- 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
