Photosynthesis Flashcards
What exits the leaf?
Gaseous water and oxygen
What enters the leaf?
Sunlight, liquid water, and carbon dioxide
List the layers of the vein of a leaf
Cuticle Upper Epidermis Palisade mesophyll Spongy mesophyll Lower epidermis Stoma Cuticle
What is xylem? What is phloem?
Xylem carries water and minerals up from the roots
Phloem carries the sugars away from the leaf
What is the purpose of a cuticle?
It prevents excess water loss, a waxy coating
Purpose of the upper epidermis?
Protection
Purpose of the palisade mesophyll?
Where photosynthesis occurs, where chloroplasts are
Purpose of the spongy mesophyll?
Exchange of gas
Purpose of lower epidermis?
Allows gas to come in and out of the lead with the guard cell
Purpose of the stoma/stomata?
Opens to let water in
How do the reactants enter the leaf?
CO2- stoma
Water- veins
Sunlight-
What is thylakoid?
Site of light dependent reaction, contains chlorophyll and is found in chloroplast
A single disk
What is grannam?
A single stack of thylakoids
What is granna
Multiple stacks of thylakoids
What is stroma?
Sight of Calvin cycle, space throughout the chloroplast
Steps of light dependent reaction
1- photosystem II
2- ETC
3- photosystem I
4- ATP Synthase
What occurs in photosystem II
Excited electrons from oxidation of water moving through the electron transport chain provide the free energy needed to pump hydrogen ions into the inner thylakoid
What occurs in photosystem I
Excited electrons leave chlorophyll and reduce NADP+ into NADPH
What occurs in the ATP Synthase
Hydrogen ions flowing out of the thylakoid via a protein chain provide the free energy needed to concert ADP into ATP
What does the ETC do?
Uses the energy from excited electrons to move hydrogen ions against the concentration gradient across the thylakoid membrane, producing a high concentration of it inside the thylakoid membrane
Three phases of the Calvin Cycle?
Carbon fixation
Reduction
Regeneration
What occurs in cabin fixation?
The 3 RuBP (5 carbon atoms) catch the 3 CO2 and forms 6 PGA
What occurs in reduction?
Energy is used, and the PGA turns into 6 PGAL (3 carbon atoms each)
What occurs in regeneration?
One PGAL is given off, which is half a glucose molecule (2 turns) and 5 continue on to go through the Calvin Cycle again
Energy flow in photosynthesis
Sunlight— electrons — ATP — glucose
Equation
6CO2 + 6H2O +energy — C6H12O6 + 6O2
Cyclic pathways in light dependent reaction
Only makes ATP no NADPH, only utilizing photosystem I, occurs when there is enough NADPH and only ATP is needed
