Photosynthesis Flashcards:
Q: Describe the structure of a chloroplast:
Chloroplasts are surrounded by a double membrane.
The inner membrane folds inwards to form thylakoid lamellae, which combine to
form stacks called grana.
Grana is where the photosynthetic pigments are located and where the reactions of
the light-independent stage take place.
The stroma is the fluid filled interior, bathing the thylakoids and grana, where the
light-independent reactions take place.
Q: Define photophosphorylation:
An endergonic reaction bonding a phosphate ion to a molecule of ADP using energy
from light, making ATP.
Q: Describe some adaptations in the structure of leaves, cells and chloroplasts that make it
efficient for trapping light:
1. Leaf’s:
Large surface area
Thin
Stomatal pores = allow carbon dioxide to diffuse into the leaf
Air spaces in the spongy mesophyll = allow carbon dioxide to diffuse to the
photosynthesising cells
Spaces between palisade cells = allow carbon dioxide to diffuse to the
photosynthesising cells
2. Cells:
Cuticle and epidermis are transparent; cellulose cell wall is thin = light penetrates
through to the mesophyll.
palisade cells are cylindrical, elongated at right angles to the surface of the leaf = to
fit a large number of cells.
3. Chloroplasts:
Large surface area
Move within palisade cells.
Rotate within palisade cells.
Pigment in the thylakoids are in a single layer at the surface of the thylakoid
membrane = pigments maximise their absorption of light
Q: How to chloroplasts act as transducers?
Chloroplasts turn energy in the photons of light into chemical energy, made available
as ATP and incorporated into molecules such as glucose.
Q: What are photosynthetic pigments?
Q: Describe the structure of a chloroplast:
Chloroplasts are surrounded by a double membrane.
The inner membrane folds inwards to form thylakoid lamellae, which combine to
form stacks called grana.
Grana is where the photosynthetic pigments are located and where the reactions of
the light-independent stage take place.
The stroma is the fluid filled interior, bathing the thylakoids and grana, where the
light-independent reactions take place.
Q: Define photophosphorylation:
An endergonic reaction bonding a phosphate ion to a molecule of ADP using energy
from light, making ATP.
Q: Describe some adaptations in the structure of leaves, cells and chloroplasts that make it
efficient for trapping light:
1. Leaf’s:
Large surface area
Thin
Stomatal pores = allow carbon dioxide to diffuse into the leaf
Air spaces in the spongy mesophyll = allow carbon dioxide to diffuse to the
photosynthesising cells
Spaces between palisade cells = allow carbon dioxide to diffuse to the
photosynthesising cells
2. Cells:
Cuticle and epidermis are transparent; cellulose cell wall is thin = light penetrates
through to the mesophyll.
palisade cells are cylindrical, elongated at right angles to the surface of the leaf = to
fit a large number of cells.
3. Chloroplasts:
Large surface area
Move within palisade cells.
Rotate within palisade cells.
Pigment in the thylakoids are in a single layer at the surface of the thylakoid
membrane = pigments maximise their absorption of light
Q: How to chloroplasts act as transducers?
Chloroplasts turn energy in the photons of light into chemical energy, made available
as ATP and incorporated into molecules such as glucose.
Q: What are photosynthetic pigments?
