Video Transcript
How are the thylakoids adapted for
their function? (A) Thylakoids contain
photosynthetic pigments within their membrane to absorb light. (B) Thylakoids have a small
surface-area-to-volume ratio, so reactions can occur more quickly. (C) Thylakoids contain specialized
enzymes that carry out the process of respiration. Or (D) thylakoids have a double
membrane that allows them to control what enters and leaves the chloroplast.
Thylakoids are disklike structures
contained within the chloroplasts of some plant cells. The thylakoids form stacks called
grana or a singular granum, and their function is to assist the chloroplast with
carrying out photosynthesis. The primary way that thylakoids are
adapted to help the chloroplast with this function is by containing photosynthetic
pigments within their membranes. These photosynthetic pigments,
which are most commonly chlorophyll A in most vascular land plants, absorb available
sunlight and transfer it to reaction centers, where the energy is used to carry out
photosynthetic reactions.
Looking at our options, it seems
that option (A) is the correct answer. But let’s double-check this by
discussing the other choices. Option (B) is not correct as the
disklike structures of the thylakoids actually provides them with a large
surface-area-to-volume ratio. It also allows them to contain more
pigments and so increase the rate of photosynthetic reactions. Option (C) is also incorrect, as
although thylakoids may contain specialized enzymes, it is to aid the process of
photosynthesis and not to aid respiration. Respiration is carried out by
different organelles, the mitochondria. Option (D) is also incorrect as the
thylakoids do not have a double membrane, and they also do not control what enters
or leaves the chloroplast. Instead, this is the role of the
double membrane that surrounds the chloroplast itself and not the membrane of the
thylakoids.
So the correct answer is option
(A). Thylakoids contain photosynthetic
pigments within their membrane to absorb light.
