Report Text: Photosynthesis

Photosynthesis is the process of converting solar energy to chemical energy and storing it inbonds of sugar. This process occurs in plants and some algae (Kingdom Protista). Plants needonly solar energy, CO2and H2O to make sugar. The process of photosynthesis takes in thechloroplasts, specifically using chlorophyll, the green pigment involved in photosynthesis.

Photosynthesis takes place primarily in plant leaves, and little to none occurs in stems, etc.

The parts of a typical leaf include the upper and lower epidermis, the mesophyll, the vascular bundle(s) (veins), and the stomates. The upper and lower epidermal cells do not havechloroplasts, thus photosynthesis does not occur there. They serve primarily as protection forthe rest of the leaf. The stomates are holes which occur primarily in the lower epidermis andare for air exchange: they let CO2in and O2out. The vascular bundles or veins in a leaf are part of the plant's transportation system, moving water and nutrients around the plant as needed. The mesophyll cells have chloroplasts and this is where photosynthesis occurs.

As you hopefully recall, the parts of a chloroplast include the outer and inner membranes,inter membrane space, stroma, and  thylakoids stacked in grana. The chlorophyll is built into the membranes of the thylakoids.

Chlorophyll looks green because it absorbs the red and blue light, making these colors unavailable to be seen by our eyes. It is the green light which is not absorbed that finally reaches our eyes, making chlorophyll appear green. However, it is the energy from the red and blue light that are absorbed that is, thereby, able to be used to do photosynthesis. The green light we can see is not/cannot be absorbed by the plant, and thus can not be used to do photosynthesis

1.    What is the function of the upper and lower epidermis?

A.   to let CO2 in and O2 out.                                             D. to enable photosynthesis.

B.   to absorb leaf green lights.                                           E. to protect the rest of the leaf.

C.   to transport the nutrient.

2.    What is the main idea of paragraph 4?

A.   the plans can be colorful in absorbing the photosynthesis process.

B.   photosynthesis needs absorption of colors.

C.   the energy to do photosynthesis is provided not by the green light.

D.   chlorophyll enables photosynthesis to absorb colors.

E.    photosynthesis process gives colors to the plans.

3.    The passage indicates that photosynthesis takes place in ....

A.   the veins                                                                      D. the stomates

B.   the membranes                                                            E. he epidermis

C.   the mesophyl