Part 4: Photosynthesis Flashcards
Upper epidermis
Produces the cuticle
Cuticle
Waxy covering on a leaf; protects from water loss due to evaporation
Palisade parenchyma
Primary sites of photosynthesis (cells have many chloroplasts), below upper epidermis
Stroma
Fluid-filled region of the chloroplast
Grana
Stacks of thylakoids, inside stroma
Thylakoids
Disk-like structures, contain chlorophyll and enzymes involved in photosynthesis
Spongy parenchyma
Irregular-shaped cells, allow for diffusion of gasses, especially CO2, w/in plant, below palisade parenchyma
Vascular bundles
Vein, contain xylem and phloem
Xylem
Transport water up the plant
Phloem
Transport food and nutrients up or down the plant (source to sink)
Lower epidermis
Bottom part of the plant leaf
Stomata
Holes on the lower epidermis that allow for gas exchange and transpiration
Guard cells
Regulate the opening and closing of stomata
Light reaction
First part of photosynthesis, requires light, results on ATP and NADPH; in thylakoid
Dark reaction
Second part of photosynthesis, does not require light, makes glucose; in stroma
Photons
Light, energy units of sunlight
Chlorophyll a, chlorophyll b, carotenoids
Light-absorbing pigments, aka antenna pigments (gather and bounce light to the reaction center)
Reaction center
Location of the special molecule that can transform light energy into chemical energy
Photosystems 1 and 2
The two types of reaction centers
Ps1 absorbs light best at 700 nanometers
Ps2 absorbs light best at 680 nanometers
Photophosphorylation
When light is used to make ATP
Photolysis
The splitting of water into oxygen, hydrogen ions, and electrons in ps 2
NADPH
The final electron acceptor in photosynthesis
Noncyclic phosphorylation
P680 captures light and pass electrons down the ETC to produce ATP
P700 captures light and pass electrons down the ETC to produce NADPH
A molecule of water is split by sunlight, releasing O, H, and e-s
Cyclic phosphorylation
P700 captures light and passes excited electrons down the ETC to produce ATP
No NADPH produced
No water split
Not as efficient
Carbon fixation
CO2 is converted into a carbohydrate (glucose)
Calvin cycle
Cycle in which CO2 enters the pathway and bonds with RuBP to form a 6 C molecule which then undergoes changes to create ATP and NADP+, and the G3P that will be made into glucose
C3 pathway
G3P is made into glucose at the end of photosynthesis
Photorespiration
Pathway that leads to the fixation of oxygen
C4 pathway
Uses PEP carboxylase fix PEP and CO2; then Co2 continues on the Calvin Cycle
Used by plants in hot dry climates
CAM photosynthesis
A way for plants in danger of loosing excessive water (meaning they have their stomata closed during the entire day) to photosynthesize even without their stomata open
