Presentation on theme: "Discovering Cells All living organisms are composed of cells, from just one to many trillions, whose details usually are visible only through a microscope."— Presentation transcript:
Discovering Cells All living organisms are composed of cells, from just one to many trillions, whose details usually are visible only through a microscope
An Overview of Cells Key concept: Cells are the basic units of structure and function in living things. Examples of function: obtaining oxygen, getting rid of waste, obtaining food, growing, and more… Cells function similarly in all organisms, they carry out the basic processes of life similarly Cells are so small they are measured in micrometers One square centimeter of Skin is more than 100,000 cells Cells are visible only through microscope
First Observations of Cells 1590ish invention of the microscope Key concept: The invention of the microscope made it possible for people to discover and learn about cells. Robert Hooke one of first people to observe cells built his own microscope- one of the best of his time observed cork which looked like small rectangular rooms they called cells
First Observations of Cells Anton van Leeuwenhook Dutch businessman Built simple microscopes in his spare time Looked at drops of lake water, scrapings from teeth and gums, water from rain gutters Animalcules- means “little animals,” small organisms that moved that he found in things like lake water
Development of the Cell Theory Schleiden- all plants are made of cells Schwann- all animals are made of cells Virchow- new cells are formed only from cells that already exist Until these men’s time people believed that cells can come from non-living matter
Cell Theory An explanation of the relationship between cells and living things i.All living things are made of cells. ii. Cells are the basic units of structure and function iii. All cells are produced from other cells
Notice the shape of each cell!
Microscopes Light Microscope Magnification: the ability to make things larger The light is bent in a light microscope in order to make the specimen larger (using a concave lens) Resolution: the ability to clearly distinguish the individual parts of a specimen
Microscopes Continued Electron Microscope Electron microscopes use a beam of electrons instead of light to produced a high magnified image Electron is a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids Allows you to see a three dimensional specimen
Microscopes Microscopes allow us to see things we cannot see with the naked eye.
Unicellular and Multicellular Unicellular- single celled Multicellular- many cells Key concept: “In multicellular organisms, cells are often organized into tissues, organs, and organ systems. Tissue- a group of singular cells that work together Organs- is made up of different kinds of tissue Organ system- a group of organs that work together to perform a major function in the body
vacuole Animal Cell
CELL WALL Prokaryotic cells (bacteria )and plant cells both have a rigid cell wall made up of polysaccharides. The cell wall provides and maintains the shape of these cells and serves as a protective barrier. Can be also found in fungi cells.
Cell Membrane Boundary between the inside of the cell and its surroundings. The cell membrane controls the movement of nutrients, water, salts, and other substances into the cell and movement of waste out of the cell. The membrane keeps out harmful bacteria, viruses, and other things that could damage the cell.
Boundaries List five boundaries that you can see around you. For each one, tell what marks the boundary. List what is kept in and what is kept out by the boundary. Example – A fence marks the boundary of the yard. The fence keeps pet dog and young children in. It keeps strange dogs and bicyclists out
Cytoplasm This is a gel-like substance that fills the cell and surround the organelles. It would be in comparison to our environment (air, land, water)
Organelles Small structures inside the cell membrane. Each organelle has a particular job to do to keep the cell working properly. The organelles are found in the cytoplasm that fills the cell.
What do all living things need to stay alive? All living things need nutrients, water, and air. All living things need a suitable place to live.
What are the characteristics of all living things? Respond to their environment, inside and out. Organized to carry out life functions. Grow and develop. Energy. Reproduce.
What do you think a single cell needs to do in order to stay alive?
Nucleus 1. Stores cell hereditary materials, DNA 2. Coordinates the cells activities (Metabolism, growing, protein synthesis, cell division (reproduction)) 3. Brain of the cell 1. Chromosomes/chromatin: codes for the DNA 2. Nucleolus: Membrane-less organism, that manufactures ribosomes. 3. Nuclear Envelope: double-layered membrane that envelopes the contents of the nucleus 4. Nuclear Pore: regulates passage of molecules between nucleus and cytoplasm.
Vacuole Water-filled sack that floats in the cytoplasm. Stores waste, water, and other substances such as food
Mitochondria Provide energy for the cell by breaking down sugar. Known as the power house of the cell In a city this would be compared to power plants Mitochondria burn fuel to provide our cells with energy. A chemical reaction called cellular respiration takes place in the mitochondria. Humans cannot live without mitochondria! Why?
Think about It: No organism can survive without energy. How do you get and use energy? Draw the concept map below, list some things in the center box that are sources of energy for your body. In the other boxes list ways your body uses energy. Sources Of Energy
Where would you expect to find more mitochondria-in very active cells such as those in your heart and liver, or in less active cells such as those in your earlobes? Explain your answer. On a sheet of paper answer the following:
Take in and use Energy Cellular respiration Mitochondria burn fuel to provide our cells with energy. A chemical reaction called cellular respiration takes place in the mitochondria. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + energy Glucose + oxygen carbon + water + energy dioxide
Plant Cell’s Power House Plant cells like animal cells have mitochondria, but they also have another kind of energy-converting organelle called chloroplast a chloroplast.. The process that plants use chloroplast is called photosynthesis. Chlorophyll is the chemical in the chloroplasts that captures sunlight.
Take in and use Energy Photosynthesis The process that plants use chloroplast is called photosynthesis. 6CO 2 + 6H 2 O +light energy C 6 H 12 O 6 + 6O 2 Carbon + water + light energy glucose + oxygen dioxide
Endoplasmic reticulum Carries materials around in the cell. Name some things in a city that would be like the endoplasmic reticulum. Sometimes known as smooth endoplasmic reticulum or rough endoplasmic reticulum if ribosome's are attached.
Ribosome's Ribosomes are the sites of protein synthesis They can be free in the cytoplasm or attached to the surface of ER They would be like factories producing needed products. Protein helps with growth and repair of a body.
Golgi Bodies 1. Final sorting and packaging of proteins and Lipids (fats) 2. How does it do that: Membrane breaks away as vesicles. 3. It is like a packaging and shipping center. (The UPS men) What does it look like? stacks of membrane-covered sacs that package and move proteins to the outside of the cell. Golgi bodies are the packaging and secreting organelles of the cell. Note: Golgi Bodies are sometimes referred to as Golgi Apparatus.
Lysosomes Lysosomes are a special type of vesiclevesicle that contain digestive enzymes. They are round structures surrounded by membranes. Lysosomes recycle materials by breaking down worn- out parts of a cell into smaller units. They deliver these materials to the cytoplasm for use in constructing new proteins. If the membrane of a lysosome breaks, the enzymes released may also destroy the cell itself, giving lysosomes the name "suicide bag".cytoplasm Lysosomes would be like waste processing plants.
Write a Dialogue: A dialogue is a conversation between at least two people. Choose two of the organelles of a plant or animal cell. Then write a dialogue between them in which they argue about which of them is more important to the cell’s survival.
You must know all the parts of an animal and plant cell… Click here to practice with an animal and plant cell