Transcript CELLS
CELLS 7-2.1 Summarize the structures and functions of the major components of plant and animal cells (including the cell wall, the cell membrane, the nucleus, chloroplasts, mitochondria, and vacuoles). Taxonomy level: 2.4-B Understand Conceptual Knowledge Cells It is essential for students to know that a cell is the smallest unit of life that conducts all life functions. In comparison to a cell an atom is the smallest unit of matter. It has properties but is not alive. Cells Our bodies have things that perform life functions like breathing, pumping blood and filtering out toxins? What are some examples of things that complete these functions? Lungs, Heart and Liver What are these called?? Organs Each cell has major structures (organelles) within it that perform these life functions. Cell Size Many organelles are too small to be seen without the aid of a microscope visual comparison of organ vs. organelles Some structures and their functions include: The Cell membrane The thin, flexible outer covering of a cell. It controls what enters and leaves a cell. What do you think this would look like? Cell membrane Diffusion is one way in which materials (for example molecules*** of sugar or water) move across the cell membrane. It occurs as materials are moved from an area of higher concentration to an area of lower concentration. Differences between Osmosis & Diffusion Osmosis is the diffusion of water across a membrane. Cytoplasm The gel-like fluid inside of a cell made of mostly water. What do you think this would look like?? The other organelles are embedded in the cytoplasm. Nucleus Contains the genetic material (DNA) and is the control center of the cell. What do you think this would look like? Vacuole Act as temporary storage centers. Some store water; others store waste products until they can be eliminated from the cell. What do you think this would look like?? Chloroplasts Are the sites where photosynthesis takes place in a plant cell. They contain the chlorophyll used to make food. What do you think this would look like? Mitochondria Are the energy producing sites in the cell where respiration takes place. It is sometimes called the “powerhouse” of the cell. What do you think these look like? Cell wall Provides support and shape for plant cells. It is made mostly of cellulose. What do you think these look like? Animal Cells & Plant Cells Compare the major components of plant and animal cells. Taxonomy level: 2.6-B Understand Conceptual Knowledge It is essential for students to know that even though all living organisms are made of cells that contain similar structures, there are differences between the structures of the cells of plants and animals. Common Structures Structures that are common to plant and animal cells are the cell membrane, nucleus, mitochondria, and vacuoles. Uncommon Structures Structures that are specific to plants : The cell wall The chloroplasts. Structural differences There are Major structural differences between a plant and an animal cell. Structural Differences Plant cells have a cell wall, but animal cells do not. Cell walls provide support and give shape to plants. Structural Differences Plant cells have chloroplasts, but animal cells do not. - Chloroplasts enable plants to perform photosynthesis to make food. Structural Differences Plant cells usually have one or more large vacuole(s), while animal cells have smaller vacuoles, if any are present. Structural Differences Large vacuoles help provide shape and allow the plant to store water and food for future use. The storage function plays a lesser role in animal cells, therefore the vacuoles are smaller. Bacteria – Shape & Structures, protists & viruses Compare the body shapes of bacteria (spiral, coccus, and bacillus) and the body structures that protists (euglena, paramecium, amoeba) use for food gathering and locomotion. Taxonomy level: 2.6-B Understand Conceptual Knowledge Bacteria & Protists It is essential for students to know bacteria by their shape It is essential for students to know protists (euglena, paramecium, amoeba), by the way they move and gather food. http://classic.sidwell.edu/us/science/vl Protists Protists are organisms that are classified into the Kingdom Protista. Protists What do the three Protists you just viewed have in common? Protists Although there is a lot of variety within the protists, they do share some common characteristics. Protists are usually one-celled organisms that live in all moist environments. They vary in the way they obtain food and move. Protists Euglena- A Protist with a Flagella------------------------------------------------------ Protists These protists move by pulling themselves with long whip like structure called flagella. These protists can have one or more flagella that help them move. The euglena is unique in that it has characteristics of both a plant and an animal, it contains chloroplasts that photosynthesize and also can consume other organisms as well. Paramecium These protists move by beating tiny hairlike structures called cilia. The cilia act as tiny oars that allow the protist to move through its watery environment. The cilia also move and help to capture food directing in toward a groove that functions like a mouth. Paramecium Paramecium—Protist with Cilia---------------------------------------------- Amoeba Amoeba—Protist with Pseudopods------------------------------------------ Amoeba These protists move by extending their bodies forward and then pulling the rest of their bodies forward as well. The finger-like structures that they project forward are called pseudopods (false foot). The pseudopods are also used to trap food. Bacteria Bacteria are organisms that are classified into the Moneran Kingdom. They are all single-celled organisms. They are classified by their body shapes. Bacteria Draw what you think of when you hear single celled organism Three types of bacteria- Classified by shapes Bacteria Spirillia ( Spirillium) - Spiral-shaped bacteria are corkscrew shaped Bacteria - Bacillus Rod-shaped bacteria Bacillus Anthreas (Anthrax) Bacteria Infection Bacteria - Coccus Spherical-shaped bacteria Example: Staphylococcus Bacteria What is something that you notice about all three types of bacteria? Viruses Viruses are tiny particles much smaller than bacteria and can only be seen with a very powerful microscope VIRUSES In isolation, viruses show none of the expected signs of life. They do not respond to stimuli, they do not grow; they do not do any of the things we normally associate with life. Therefore, they should not be considered as living organisms at all. VIRUSES However, viruses do show one of the most important signs of life: the ability to reproduce. VIRUSES Viruses are considered to be nonliving until they infect the cells of a host plant or animal and reproduce within those cells. VIRUSES Viruses are responsible for causing many diseases in living organisms (for example chickem pox, AIDS, colds, and flu in humans).