Introduction to the Cell Cell theory Cell structure Cell types quiz video lecture lab 1: microscope, onion, cheek draw lab 2: video, make microscope worksheet

Cell Theory The invention of the microscope about 300 years ago led to the discovery of the cell and the formulation of the cell theory : All organisms are made up of one or more cells The cell is the basic unit of all organisms All cells arise from pre-existing cells Microscope Cell theory Cells Basic unit Pre-existing

Cell Structure Part 1 All cells contain these common components: Cell membrane is a double layer of lipid that surrounds the cell, it is used for protection, transportation and communication Cytoplasm is the stuff inside the cell membrane Cytosol is the fluid part of the cytoplasm DNA is the genetic material of a cell Cell membrane Cytoplasm Cytosol DNA

Cell Structure Part 2 Some cells also have components called organelles meaning “little organs” Nucleus stores and replicates the cell’s DNA Endoplasmic reticulum is a larger network of tubes that produces and modifies chemicals Golgi body is a smaller network of tubes that modifies and delivers chemicals Organelles Nucleus Endoplasmic reticulum Golgi complex

Cell Structure Part 3 Ribosome makes proteins Lysosome breaks down chemicals Mitochondria uses respiration to release energy Chloroplast uses photosynthesis to store energy in plants Centrosome directs transport and cell division Vacuole stores chemicals Ribosomes Lysosome Mitochondria respiration Chloroplast photosynthesis Centrosome Vacuole

Cell Types Bacteria Animal Plant Type Prokaryotic Eukaryotic Size Small 1-10 μm 10-100x larger Organelles No Yes Organization Unicellular Multicellular External Structures Flagella and capsule Cilia Cell wall