Cellular Respiration s2

Cellular Respiration

Mitochondria are known as the powerhouse of the cell. They are organelles that act like a digestive system that takes in nutrients, breaks them down, and creates energy for the cell. The process of creating cell energy is known as cellular respiration. Most of the chemical reactions involved in cellular respiration happen in the mitochondria. A mitochondrion is shaped perfectly to maximize its efforts.

The chemical equation for the cellular respiration process is: C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (as ATP)

The word equation for this is: Glucose + Oxygen → Carbon dioxide + Water + Energy (as ATP)

1. Why are mitochondria known as the powerhouse of the cell? 2. What is cellular respiration? 3. Where does cellular respiration occur in the cell? 4. What is meant by “maximize its efforts?” 5. What is the chemical equation for the cellular respiration process? 6. What is the word equation for the cellular respiration process? 7. What is taken in by the mitochondria during this process? 8. What is produced by the mitochondria during this process?

Mitochondria

Mitochondria are very small organelles. You might find cells with several thousand mitochondria. The number depends on what the cell needs to do. If the purpose of the cell is to transmit nerve impulses, there will be fewer mitochondria than in a muscle cell that needs loads of energy. If the cell feels it is not getting enough energy to survive, more mitochondria can be created. Sometimes they can even grow, move, and combine with other mitochondria, depending on the cell's needs.

9. Why might some cells contain more mitochondria than others? 10. What is an example of a cell that might have many mitochondria? 11. What occurs in the cell if not enough energy is being created?

Mitochondria Structure

Mitochondria have two membranes (not one as in other organelles). The outer membrane covers the organelle and contains it. The inner membrane folds over many times (cristae). That folding increases the surface area inside the organelle. Many of the chemical reactions happen on the inner membrane of the mitochondria. The increased surface area allows the small organelle to do as much work as possible. If you have more room to work, you can get more work done. Similar surface area strategies are used by microvilli in your intestinal cells. The fluid inside of the mitochondria is called the matrix.

12. How many membranes does a mitochondrion have? 13. What is the function of the mitochondria’s outer membrane? 14. Why does the inner membrane of the mitochondria fold over many times? 15. Why is increased surface area beneficial to the organelle? 16. What is another example of how increased surface area is used in humans? 17. What do you call the fluid found in the inside of mitochondria? Photosynthesis Worksheet

Chloroplasts Photosynthesis is a process in which sunlight energy is used to make glucose. The site of photosynthesis is in the chloroplast – a organelle found in the leaves of green plants. The main functions of chloroplasts are to produce food (glucose) during photosynthesis, and to store food energy. Chloroplasts contain the pigment, chlorophyll. Chlorophyll absorbs most of the colors in the color spectrum, and reflects only green and yellow wavelengths of light. This is why we see leaves as green or yellow – because these colors are reflected into our eyes.

1. What is photosynthesis? 2. Where does photosynthesis occur? 3. What are chloroplasts and where are they found? 4. What are the two main functions of chloroplasts? 5. Why doe most leaves appear green? 6. What is the primary pigment found in the chloroplast?

Photosynthesis

Glucose is another name for sugar. The molecular formula for glucose in C6H12O6. Plants make sugar by using the energy from sunlight to transform CO2 from the air with water from the ground into glucose. This process, called photosynthesis, occurs in the chloroplast of the plant cell. During this process, oxygen (O2) is created as a waste product and is released into the air for us to breath. The formula for photosynthesis is:

CO2 + H2O + sunlight ---- C6H12O6 + O2

This formula says that carbon dioxide and water molecules are combined with the energy from sunlight to produce sugar and oxygen. The reactants in photosynthesis (what is used) are CO2, water and sun. The plant gets water from the ground through its roots. The plant collects carbon dioxide from the air. Much of the carbon dioxide comes from living organisms that exhale it, but some also comes from factory smokestacks and car fumes.

7. What is the formula for photosynthesis? 8. What three things are used to make glucose in photosynthesis? 9. Where does the water come from? 10. Where does the water enter the plant? 11. What are some sources of CO2? 12. What type of energy does the plant use to convert CO2 and H2O into sugar?

The products (what is made) are glucose and oxygen. The glucose produced is used by the plant for energy and growth. We also use this glucose by eating plants. The oxygen produced is released into the air for us to breath. Photosynthesis is essential for all life on earth, because it provides food and oxygen.

13. What is produced in photosynthesis? 14. What is the glucose used for? 15. What is the oxygen used for?