Reviewer in General Biology.pdf

Reviewer in General Biology Cell Theory - Also known as cell doctrine - States that all organisms are composed of similar units of organization called cells. History Leading up to Cell Theory Zacharias Jansen - Of Middleburg, Holl...

Reviewer in General Biology Cell Theory - Also known as cell doctrine - States that all organisms are composed of similar units of organization called cells. History Leading up to Cell Theory Zacharias Jansen - Of Middleburg, Holland, around the year 1595 - First compound microscope Robert Hooke - English scientist - Observed cells in cork - Approx. 1663 Anton Van Leeuwenhoek - First to observe bacteria and protozoa - Called “animacules” - Approx. 1673 Robert Brown - British botanist - Discovered the nucleus of a cell - 1833 Theodor Schwann - German doctor - Described animal cells with a nucleus - 1838 Matthias Schleiden - German botanist - Described plant cells with nucleus - 1838 Rudolf Virchow - German doctor - Stated “every cell originates from another cell.” - 1855 Tenants of Modern Cell Theory - All known living things are made up of cells. - The cell is structural and functional unit of all living things - All cells come from pre-existing cells by division. - Cells contain hereditary information which is passed from cell to cell during cell division - All cells are basically the same in chemical position - All energy flow (metabolism and biochemistry) of life occurs within cells. ay  Cell Structure and Function Cell - The smallest unit that is capable of performing life functions. - Examples: o Amoeba Proteus o Plant Stem o Bacteria o Red Blood Cell o Nerve Cell Types of Cells 1. Somatic Cell 2. Sex Cell 3. Prokaryotic Cell 4. Eukaryotic Cell Prokaryotic Cell - Do not have structures surrounded by membranes - Few internal structures - One-celled organisms, Bacteria Eukaryotic Cell - Contain organelles surrounded by membranes - Most living organisms Cell Parts Organelles Surrounding the Cell Cell Membrane - Outer membrane of cell that controls movement in and out of the cell - Double layer - It serves as barriers and gatekeepers - Both animal and plant have a cell membrane - Lipid Layers yung nasa loob Cell Wall - Most commonly found in plant cells and bacteria - Supports and protects cells Inside the Cell Nucleus - Directs cell activities - Separated from cytoplasm by nuclear membrane - Contains genetic material – DNA Nuclear Membrane - Surrounds nucleus - Made of two layers - Opening allow - Made of two layers ay Chromosomes - In nucleus - Made of DNA - Contain instructions for traits and characteristics - 24 pairs of chromosomes Cytoplasm - Gel-like mixture - Surrounded by cell membrane - Contains hereditary material Endoplasmic Reticulum - Moves materials around in cell - Smooth type: lacks ribosomes - Rough type: ribosomes embedded in surface Ribosomes - Each cell contains thousands - Make proteins - Found on ribosomes and floating throughout the cell Mitochondria - Produces energy through chemical reactions – breaking down fats and carbohydrates - Controls level of water and other materials in cell - Recycles and decomposes proteins, fats, and carbohydrates - Power house Golgi Bodies - Protein ‘packaging plant’ - Move materials within the cell - Move materials out of the cell Lysosome - Digestive ‘plant’ for proteins, fats and carbohydrates - Transports undigested material to cell membrane for removal - Cell breaks down if lysosome explodes Vacuoles - Membrane-bund sacs for storage, digestion, and waste removal - Contains water solution - Help plants maintain shape - Janitor ng cells Chloroplast - Usually found in plant cells - Contains green chlorophyll - Where photosynthesis takes place. ay