Using Energy

Metabolism The chemical energy stored in food is changed in cells into forms needed to perform all the activities necessary for life. The total of all chemical reactions in an organism is called metabolism.

Living things are divided into 2 groups: Producers Organisms that make their own food, such as plants Also called AUTOTROPHS Consumers Organisms that cannot make their own food, such as insects Also called HETEROTROPHS

Photosynthesis Plants and many other producers convert sunlight energy into chemical energy, which is used to make sugars, which can be used as food.

Producing Carbohydrates Producers that use photosynthesis are usually green because they contain a green pigment called chlorophyll, which is used to capture sunlight energy, and can be found in chloroplasts.

Captured sunlight energy is used to drive chemical reactions, where raw materials, carbon dioxide (CO2), and water (H2O) are used to produce sugar and oxygen.

Carbon Dioxide + Water + Light Energy Photosynthesis Equation: 6CO2 + 6H2O + Light Energy C6H12O6 + 6O2 Carbon Dioxide + Water + Light Energy → Glucose + Oxygen

Storing Carbohydrates Plants make more sugar during photosynthesis than they need, so excess sugar is changed and stored as starches or other carbohydrates, which are used for growth, maintenance, and reproduction.

Respiration Chemical reactions occur that break down food molecules into simpler substances and release their stored energy.

Breaking Down Carbohydrates Respiration of carbohydrates begins in the cytoplasm. Carbs are broken down into glucose molecules, then into 2 simpler molecules in the mitochondria. This uses O2 & releases energy, and produces CO2 & H2O as waste.

Photosynthesis Vocab Review Worksheet Water, carbon dioxide, and sunlight are the three ingredients needed for photosynthesis to occur. Through photosynthesis, plants convert these ingredients into glucose, a food used by the plant. Chlorophyll is the material in green plant cells that traps energy from the sun. The plant takes in a gas called carbon dioxide from the air. Chlorophyll is found in the chloroplasts, structures within the cell where photosynthesis will take place.

Water is a material the plant takes up through its roots and stems. During photosynthesis, oxygen is a waste product released by the plant into the air. Plants produce more glucose than they need. The excess glucose is stored by the plant as carbohydrates or starches. Plants also change glucose into cellulose, the structural material used in their cell walls. While chlorophyll is found in most aboveground parts of green plants, most photosynthesis takes place in a plant’s leaves.

In many regions, there is not enough sunlight or water during winter for photosynthesis to occur. Most plants are also called autotrophs/producers because they are able to produce their own food. Most animals are called heterotrophs/consumers because they obtain energy from other plants or animals.

Workbook pages 47-49 #’s 1-11 What happens during respiration? Cells break down simple food molecules such as sugar and release the energy they contain. Cells store energy in the form of carbohydrates How do cells “withdraw” energy? Cells break down carbohydrates to make energy Respiration that takes place inside of cells is the same as breathing air in and out of the lungs. False

5. Respiration Raw materials Products Event in respiration Sugar Oxygen Products Carbon dioxide Water Energy Event in respiration B – 6. takes place in the mitochondria A – 7. takes place in the cytoplasm B – 8. Oxygen is involved C – 9. Energy is released A – 10. Glucose molecules are broken down Stage of process A) first stage B) second stage C) both first and second stages

Fermentation When cells don’t have enough oxygen for respiration, they use a process called fermentation to release some of the energy stored in glucose molecules.

More Fermentation Begins in the cytoplasm, but the simple molecules from the breakdown of glucose don’t move into the mitochondria; rather, more chemical reactions occur in the cytoplasm that release energy and produce wastes (lactic acid, alcohol, CO2).

Fermentation creates… Cheese Lactic Acid Yogurt Alcohol Bread

- Photosynthesis

- Photosynthesis

- Respiration

- Respiration