Essential Question: What are Cells Made of? Cells and Life Processes Ms. De Los Rios 6th Grade Cells and Homeostasis ch. 10.3 Essential Question: What are Cells Made of? How Do Cells Maintain Homeostasis? Pg. 378-379

Vocabulary Homeostasis- is the maintenance of internal stable conditions that are necessary for life. Cellular respiration- cells break down glucose molecules in the presence of oxygen, releasing energy. Photosynthesis- cells capture energy in sunlight and convert it to energy stored in food. Cell Membrane- surrounds a cell and separates it from the outside environment. Diffusion- molecules move from an area of higher concentration ( many molecules) to an area of lower concentration (fewer molecules) Cell Division- is the process in which one cell splits into two new cells that are genetically identical to the original cell.

Levels of Organization Levels of Organization REVIEW Levels of Organization Levels of Organization Living things are organized in levels of increasing complexity. Complete the missing terms to show the patterns of organization of organisms from simple to complex.

How Do Cells Have Homeostasis? Pg. 377 Have you ever felt sweaty? The evaporation of sweat from your skin helps cool off your body. Keeping your body temp. about the same in spite of the temp. outside is one example of how your body maintains homeostasis. Entire organisms maintain homeostasis. To maintain homeostasis, materials such as food and oxygen must move into cells. Homeostasis- is the maintenance of internal stable conditions that are necessary for life. In all cells, the processes that help maintain homeostasis include getting and using energy from food and removing waste.

How Do Cells Have Homeostasis? Pg. 377 GETTING AND USING ENERGY Most organisms get energy from cell processes that break down foods. ENERGY FROM FOOD During cellular respiration, cells break down glucose molecules in the presence of oxygen, releasing energy. Waste products of this process include carbon dioxide and water. Animals and some other organisms get food for energy by eating other organisms. MAKING FOOD Unlike animals, plants and some other organisms can make their own food. The process by which cells capture the energy in sunlight and convert it to energy stored in food is called photosynthesis. Often, the foods produced in photosynthesis are glucose or other sugars. The raw materials for photosynthesis are carbon dioxide from the air and water. Oxygen leaves the cell as a waste product.

Cells and Homeostasis pg. 377 FIGURE 1 Energy From Food Florida’s orange crop comes from the energy captured in photosynthesis. The 2008–2009 crop totaled 162 million boxes. 1.)Which process applies to each organism? 2.)How does energy from the sun become energy the boy can use? -__________________________________________________________________________________________________________________________________________________________________________________________

How Do Cells Have Homeostasis? Pg. 377 To maintain homeostasis, materials such as food and oxygen must move into cells. At the same time, waste materials must exit. Materials that move in or out of a cell must cross a structure called the cell membrane. The cell membrane surrounds a cell, separates it from the outside environment, and controls which substances enter and leave. One way materials move across the cell membrane involves collisions of molecules. These collisions push molecules away from one another in a process called diffusion. During diffusion, molecules move from an area of higher concentration to an area of lower concentration. Eventually, the molecules spread evenly throughout a space

Some materials move across the cell membrane by way of diffusion. Fig. 2 Cells and Homeostasis pg. 378 Diffusion Some materials move across the cell membrane by way of diffusion. Draw an arrow to show the overall direction that molecules will travel as a result of diffusion.

All multicellular organisms grow during some part of their lifetimes All multicellular organisms grow during some part of their lifetimes. They also have structures that wear out or become injured and must be replaced. Growth and repair can occur because cells reproduce, or make more cells. Cell division is a process in which one cell splits into two new cells that are genetically identical to the original cell. Through cell division, your body replaces damaged skin cells and worn out blood cells. Reproduction of cells is one of the processes that helps multicellular organisms maintain homeostasis. You grow as your body produces more muscle cells, bone cells, and other kinds of cells. Growth and repair help your body maintain homeostasis.