Photosynthesis+Reading+Assignment

The mesophyll tissue has cells containing the most chloroplasts.
 * Leaves** contain a **mesophyll** tissue layer where photosynthesis occurs.

Chloroplasts contain stacks of **thylakoids** called **grana** (stack). The filling is called **stroma**.



Pigments are embedded in the membrane of each thylakoid.

Plants need Sunlight, Water and Carbon dioxide to carry out photosynthesis Plants produce Glucose (sugar) and Oxygen as products. The sugars are stored.

Photosynthesis Equation: H2O + CO2 (with sunlight) à C6H12O6 + O2

The **light-dependent reactions** occur in the thylakoid. The **light-independent reactions** occur in the stroma.

Photosynthesis occurs in a series of events: 1. Water is absorbed from the roots (capillary action from adhesion and cohesion) and transported out to the leaves. 2. Water splits and the electrons get excited from the Sun (light energy). (**Electron transport chain** in the pigments of the thylakoid) 3. The excited electrons transfer their energy to ATP molecules. 4. Carbon dioxide is absorbed through the stoma. 5. The ATPs are used to convert Carbon dioxide into Glucose. (The **Calvin Cycle** in the stroma) 6. Oxygen, a by-product from water splitting, is released out the stoma. Energy conversions for photosynthesis:

Light Energy à Chemical Energy à Chemical Energy Sunlight à ATP à Glucose


 * Plants use solar energy to convert water and carbon dioxide into organic compounds and oxygen.**

Retrieval Questions Answer the following questions without going back to the reading. Then after you have written out your answers, go back to the reading and check yourself. Indicate that you have corrected your own answers by correcting them in a different color pen. 1. Which plant tissue (layer) contains the most chloroplasts? 2. There are two main parts of a chloroplast where the two stages of photosynthesis occur. Identify these parts. 3. Why are pigments like chlorophyll necessary for photosynthesis? 4. Does a plant make ATP molecules during photosynthesis? If so, for what purpose? 5. Write the equation for photosynthesis. Include Sunlight and ATP. Illustrate which parts of the equation are Light Energy, the first Chemical Energy made and the second Chemical Energy made.