Unit 1 Lesson 6 Photosynthesis and Cellular Respiration. Copyright Houghton Mifflin Harcourt Publishing Company

Transcription

1 Unit 1 Lesson 6 Photosynthesis and Cellular Respiration

2 Energize! How do the cells in an organism function? Cells must capture and use energy or they will die. Without energy, living things cannot replace cells, build body parts, or reproduce. Food contains chemical energy that cells need to carry out life processes.

3 How do the cells in an organism function? Producers make their own food. Most use energy from the sun. Some use chemicals to make food. Consumers must eat other living things to get food. They may eat producers or other consumers. Decomposers get energy by breaking down dead organisms or wastes of other organisms.

4 Cooking with Chloroplasts How do plant cells make food? Photosynthesis is a process by which plants use energy from sunlight, carbon dioxide, and water to make sugars. Oxygen is released into the air during photosynthesis.

5 How do plant cells make food? Photosynthesis takes place in organelles called chloroplasts. A green pigment called chlorophyll in chloroplasts captures energy from sunlight. This energy is used to combine carbon dioxide and water to form the sugar glucose and oxygen gas.

6 How do plant cells make food? 6CO 2 + 6H 2 O + light energy C 6 H 12 O 6 + 6O 2 Plants store glucose, which is a sugar that stores chemical energy. When organisms eat plants, they use the stored sugars for energy.

7 How do plant cells make food? What occurs in the organelle shown below?

8 Mighty Mitochondria How do cells get energy from food? Energy in sugars is stored in a molecule called adenosine triphosphate (ATP). Cellular respiration is the process of breaking down food to produce ATP.

9 How do cells get energy from food? Cellular respiration takes place in the cytoplasm and cell membranes of prokaryotic cells. In eukaryotes, cellular respiration takes place in organelles called mitochondria. Glucose is first broken down into two 3-carbon molecules in the cytoplasm, releasing energy.

10 How do cells get energy from food? Oxygen enters the cell and travels to the mitochondria. The 3-carbon molecules are broken down in the mitochondria, where energy is captured and stored as ATP. The products of cellular respiration are chemical energy (ATP), carbon dioxide, and water.

11 How do cells get energy from food? In many animals, carbon dioxide is carried to the lungs to be released during breathing. Some of the energy produced during cellular respiration is released as heat. Much of the energy produced is transferred to ATP. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + chemical energy (ATP)

12 How do cells get energy from food? What is the role of mitochondria during cellular respiration?

13 Merry-Go-Round! How are photosynthesis and cellular respiration connected? Plants need carbon dioxide for photosynthesis, and they release oxygen. During cellular respiration, other organisms use this oxygen and release carbon dioxide. Photosynthesis and respiration are linked, each depending on the products of the other.

14 Out of Air Anaerobic respiration, which is respiration without oxygen, can occur if there is not enough oxygen. Fermentation is a form of anaerobic respiration used by yeasts. The body uses anaerobic respiration during hard exercise. The lactic acid produced makes muscles sore.