Photosynthesis & Respiration

Cells need Energy  Cells need a constant supply of energy.  Animal cells get energy from food, while plant cells get energy from the sunlight.  All cells use chemical energy  is the energy stored in the bonds between atoms of every molecule.  Major source for most cells is stored in a sugar molecule called glucose.

What is Photosynthesis? The process of photosynthesis is a chemical reaction. It is the most important chemical reaction on our planet.

What is the equation for the chemical reaction of photosynthesis? Six molecules of carbon dioxide react with six molecules of water to form 1 molecule of glucose and six molecules of oxygen.

Describe Photosynthesis

 The process of changing light energy to chemical energy  Energy stored as sugar  Occurs in plants and some algae  Plants need light energy, CO 2, and H 2 O  Takes place in the chloroplasts, using chlorophyll, the green pigment in plants chloroplasts chlorophyll

What happens during photosynthesis?  Plants capture light energy and use that energy to make glucose. Plants also need to take in carbon dioxide from the air and water from the soil.  Sunlight provides the energy needed by chlorophyll to change molecules of carbon dioxide and water into glucose  Main goal of photosynthesis is to make sugar for the plant to use as energy.  Oxygen is also released in this reaction as a biproduct.

What happens with the sugar?  The plant will use the sugar (glucose) for energy.  Extra glucose will be linked together in long linked carbohydrates called starch.  They are stored in the cell and later break the starch back down to glucose to use as energy.

Why is this important to us? We cannot make our own food (glucose, energy), we must get our food from plants. Plants are the first step in the food chain. The oxygen released during photosynthesis is necessary for all living things.

What is Cellular Respiration? The release of chemical energy for use by cells.

What is Cellular Respiration? Once the energy that was in sunlight is changed into chemical energy by photosynthesis, an organism has to transform the chemical energy into a a form that can be used by the organism. photosynthesis This process is cellular respiration.

Describe Cellular Respiration  The breakdown of glucose molecules to release energy  Takes place in all living things  Is a step by step process, takes place in mitochondria.

What is the chemical equation for cellular respiration?