Transcript Chapter 8
Structure and Function of Plant and Animal Cells Anton van Leeuwenhoek: 1600s, experimented with glass and diamond and was able to magnify bacteria Two lenses which magnify objects Illuminate specimens between 400 and 1000 times Invented in Germany in 1932, refined in 1938 in Canada Magnifies objects up to 600,000 times Transmission electron microscope Focuses electrons at the object being studied Specimen must be dead and is covered in chemicals when it is observed Scanning electron microscope Beam of electrons is passed over specimen A 3D image is focused on a screen Living organisms can be examined http://www.pbrc.hawaii.edu/microangela/ The cell is the smallest unit of life Cells are made up of organelles which each carry out a certain function Organelles are made up of atoms Atoms are the smallest unit of matter Cells combine together to form tissues, muscle is a tissue Tissues combine together to form organs, can you think of examples of organs in the human body? Organs work together in systems, examples include the digestive, respiratory and circulatory systems Robert Hooke was the first person to use the term cell He looked at samples of cork in the 1600s The cell theory contains 3 key points ◦ All living things are made up of cells ◦ Cells are responsible for structure and function in living organisms ◦ Cells come from pre-existing cells, they reproduce Plant Animal Nucleus: the control center or brain of the cell, holds the DNA which contains the genetic information Cytoplasm: surrounds the nucleus, holds the organelles in place Mitochondria: the powerhouse of the cell, makes energy using food and oxygen Vacuole: stores, water, food and waste until the cell needs it, looks like an empty sac Endoplasmic reticulum (ER): transports materials such as food, water and waste in and out of the cell Golgi body: packages and transports protein, holds waste until the cell can get rid of them, part of the ER Cell membrane: a semi permeable layer that separates the cell from it’s environment, allows some things in and out while not allowing other things in and out Cell wall: found only in plant cells, non-living, provides protection and strength for the cell Chloroplast: contains chlorophyll which gives plants their green color, where photosynthesis occurs, located in plant cells only Cytoplasm = whole area of the cell Cell membrane = city gates Nucleus = city hall Mitochondria = power plant Vacuole = sewage treatment plant and water storage plant Golgi = dump Chloroplast = gardens ER = roads Contains chlorophyll which gives plants their green color. Located in plant cells only. Provides a large surface area to collect sunlight for photosynthesis. Short form ER Responsible for transporting materials such as food, water and waste through the cell. The Golgi body packages and transports proteins through the cell and holds the cells waste products until its ready to get rid of them. This is a specialized part of the ER. The nucleus is circular shaped, found close to the middle of the cell. It is known as the “brain” of the cell. The nucleus is basically the control center of the cell. The cell wouldn’t survive without the nucleus. This contains the DNA DNA holds the hereditary instructions.