Transcript Cells
+ + Cells Remember… Actual cell with fluorescent dye for studying and learning purposes. Simple organisms such as bacteria, are single cell. Plants and animals are made up of many cells. Each kind of cell has a particular function. Illustration of cell for teaching purposes. + Functions of Cells The cell is like a little town. A town in comprised of citizens and workers—each citizen has a different job in the city. These different jobs are necessary in order for the town to operate efficiently and effectively. The cell works similarly. Its organelles are its workers. Each organelle has a different job that is necessary for the cell to function efficiently and effectively. Cells: Size & Shape • A cell’s size and shape depend upon its function. • Red blood cells are small and disc shaped to fit through the + blood vessel. smallest • Muscle cells are long and thin. When they contract they produce movement. • Nerve cells which carry signals to the brain are very long. Animal Cell (Round Shaped) + Plant Cell (Square Shaped) + Cell Membrane Holds the cell together. Keeps all of the pieces (like the organelles and the cytoplasm) inside the cell. Controls what goes in and out of the cell. Example: Chicken egg with a hard shell that allows air (gas) to move from outside the egg to inside the egg for the chick to breathe. + Cytoplasm Cytoplasm A jellylike substance that is located inside the cell membrane and supports all the cell’s organelles and contains many chemicals to keep the cell functioning. + Nucleus The “brain” of the cell. Controls all of the cellular activities—including cell reproduction. Nucleus The nucleus is guided by the cell’s DNA that are located on thread-like structures called chromosomes. The chromosomes carry the information that determines what traits a living organism will have. + Nucleus 1. Chromatin 2. Nucleolus Chromatin—Thin strands of genetic material and proteins that direct the cell’s functions, with respect to cell reproduction. Nucleolus—Small round structure in the nucleus. Ribosomes are made here—but pass through nucleus membrane to be in the cytoplasm. + Mitochondria Mito = Might/Power A rod-shaped structure that floats in the cytoplasm. Mitochondria are the powerhouses of the cell. It converts energy stored in food to energy the cell can use to live and function. If a cell needs a lot of energy then it will have more mitochondria. + Endoplasmic Reticulum A network of membranes consisting of folded sacs and tunnels in the cytoplasm. It is “ribbony” looking. Ribosomes dot some parts of the ER, while other ribosomes float freely in the cytoplasm. The ER helps the attached ribosomes make proteins. Once the proteins are made, they leave the ribosome to another organelle. + Ribosomes The sites of protein synthesis in a cell (make protein). Protein provides the energy the cell needs to do everything. These small, spherical structures are the most numerous organelles in almost all cells. They may number in the millions. + Golgi Apparatus As proteins leave the ER, they move to a structure that looks like flattened sacs--Golgi apparatus. The Golgi apparatus receives the proteins and other newly formed material from the ER and packages them and distributes them to other parts of the cell or to the outside of the cell. + Vacuoles Vacuoles and vesicles are storage organelles that hang onto water, waste, and food until it is needed. Some vacuoles store waste products until the waste is removed from the cell. All plant cells have vacuoles. Some animal cells have vacuoles; while others do not. + Lysosomes Lysosomes break down food, cell waste, and all worn out cell organelles. Lysosomes are the cell’s recycling center. + Plant Cells vs. Animal Cells Plant cells basically have two additional organelles that animal cells do not have. Cell wall. The shape of the plant cell is primarily determined by the cell wall which surrounds the cell membrane. The cell wall can be compared to the skeleton of the human body, thus, it is the main supporting structure of the cell and is the skeleton of the cell. Chloroplast. These organelles capture sunlight do drive photosynthesis--a process that makes food for the cell. Chloroplast is responsible for the green color of plants. + Seven Life Processes All living organisms exhibit the following seven life processes. M Movement Animals move to find food and away from predators. Plants move towards light. R Reproduction Both animals and plants reproduce to make their species carry on. S Sensitivity Animals and plants are sensitive to light. G Growth Animals grow larger and stronger which helps them hunt better. R Respiration Animals and plants must turn their food into energy. E Excretion Waste products must be excreted from plants and animals. N Nutrition Animals need food for respiration and plants need miner.