Presentation on theme: "Cells Structure and Function. Cell Vocabulary Make a flashcard for these terms: 1.Cell 2.Cell theory 3.Cell membrane 4.Cell wall 5.Nucleus 6.Cytoplasm."— Presentation transcript:
Nucleus Cells carry coded information in the form of DNA. In some cells DNA floats freely inside the cell In other cells the DNA is found in a membrane- bound organelle: the NUCLEUS Most functions of a cell are controlled by the nucleus. The NUCLEOLUS is a small structure within the nucleus where ribosomes are assembled.
Endoplasmic Reticulum System of tubes and sacs Moves materials around in cell Smooth type: lacks ribosomes Rough type (pictured): ribosomes embedded in surface http://library.thinkquest.org/12413/structures.html
Smooth Endoplasmic Reticulum Transports materials throughout the cell. Digests lipids. Produces proteins.
Rough Endoplasmic Reticulum Covered with ribosomes. Produces proteins. Transports materials throughout the cell.
Mitochondria, aka “Mighty-Chondria” This organelle processes energy for a cell. It makes ATP by breaking down glucose to Carbon dioxide. (ATP = energy) Involved in cellular respiration Controls level of water and other materials in cell Recycles and decomposes proteins, fats, and carbohydrates Mitochondria even have their own DNA!
Cell Coloring! Quiz on Eukaryotic cell at next meeting!! Plant and Animal Cell Coloring sheet
Movement through the Membrane Cell’s outer boundary Covers a cell’s surface and acts as a barrier between the inside and outside of the cell All materials enter and exit through the plasma membrane Membrane is SEMIPERMEABLE: allows only certain materials in and out.
Cell Homeostasis Cell membranes help organisms maintain homeostasis by controlling what substances may enter or leave cells. There are two main ways of transporting materials into and out of a cell: Passive Transport and Active Transport
Passive Transport Passive transport without any energy Passive transport occurs when substances cross the cell membrane without any energy by the cell Transport with NO Energy—riding a bike downhill Diffusion and Osmosis are the primary methods of Passive Transport
Diffusion Simplest form of passive transport Movement of molecules from an area of higher concentration to lower concentration The difference in the concentration of molecules across a distance is called a CONCENTRATION GRADIENT Molecules will move from one area to another until it reaches EQUILIBRIUM, or a balance.
Osmosis Osmosis is the passive (no energy required) transport of water across a cell membrane Water moves from areas of high concentration to low concentration When the concentration of solute molecules outside the cell is lower than inside the cell, the solution outside the cell is HYPOTONIC to the cell. In this situation water diffuses INTO the cell until equilibrium is established.
Osmosis If the solution outside the cell is higher than the inside the cell the solution is HYPERTONIC and the water diffuses out of the cell to reach equilibrium When the concentrations are equal=ISOTONIC
Active Transport When cells need to transport materials from an area of low concentration to high concentration (the opposite of what would naturally happen) it is called ACTIVE TRANSPORT, the cell needs to use ENERGY.
Endocytosis The process by which cells ingest external fluid, macromolecules, and large particles.
Exocytosis Process by which a substance is released from a cell