Section 7.1 Summary – pages 171-174 The Cell Theory Before microscopes were invented, people believed that diseases were caused by curses and supernatural spirits. As scientists began using microscopes, they quickly realized they were entering a new world–one of microorganisms. Microscopes enabled scientists to view and study cells, the basic units of living organisms. Section 7.1 Summary – pages 171-174

Section 7.1 Summary – pages 171-174 The Cell Theory Robert Hooke was an English scientist who lived at the same time as van Leeuwenhock (the first person to use a microscope). Hooke used a compound light microscope to study cork, the dead part of oak tree bark. Hooke named the compartments he saw in the cork “cells.” He and some other scientists concluded that cells are the basic building blocks of all living things. Section 7.1 Summary – pages 171-174

Section 7.1 Summary – pages 171-174 The Cell Theory 1. All organisms are composed of one or more cells. 2. The cell is the basic unit of organization of organisms. 3. All cells come from preexisting cells. Remember, no spontaneous generation! Section 7.1 Summary – pages 171-174

Section 7.1 Summary – pages 171-174 Two Basic Cell Types Cells that do not contain internal membrane-bound structures are called prokaryotic cells. The cells of most unicellular organisms such as bacteria do not have membrane bound structures and are therefore called prokaryotes. Section 7.1 Summary – pages 171-174

Section 7.1 Summary – pages 171-174 Two Basic Cell Types Cells containing membrane-bound structures are called eukaryotic cells. Most of the multi-cellular plants and animals we know are made up of cells containing membrane-bound structures and are therefore called eukaryotes. Section 7.1 Summary – pages 171-174

Section 7.1 Summary – pages 171-174 Two Basic Cell Types The membrane-bound structures within eukaryotic cells are called organelles. Each organelle has a specific function that contributes to cell survival. Section 7.1 Summary – pages 171-174

Summary Section 2 – pages 175-178 Plasma Membrane : aka “The Cell Membrane” All living cells must maintain a balance regardless of internal and external conditions. This balance is Homeostasis. Survival depends on the cell’s ability to maintain the proper conditions within itself. Summary Section 2 – pages 175-178

Summary Section 2 – pages 175-178 Plasma Membrane The plasma membrane is the boundary between the cell and its environment. Summary Section 2 – pages 175-178

Summary Section 2 – pages 175-178 Plasma Membrane allows a steady supply of glucose, amino acids, and lipids to come into the cell no matter what the external conditions are. removes excess amounts of these nutrients when levels get so high that they are harmful. allows waste and other products to leave the cell. Summary Section 2 – pages 175-178

Summary Section 2 – pages 175-178 Plasma Membrane By controlling what goes in and out of the cell, the plasma membrane maintains homeostasis. The plasma membrane is able to maintain homeostasis because it is selectively permeable, it only allows specific molecules in and out. Summary Section 2 – pages 175-178

Summary Section 2 – pages 175-178 Plasma Membrane Nutrients Nutrients Water Nutrients OOPS! Can’t go in! Waste Waste Summary Section 2 – pages 175-178

Summary Section 2 – pages 175-178 Plasma Membrane The plasma membrane is composed of two layers of phospholipids back-to-back (or lipid-to-lipid). Phospholipids are lipids with a phosphate attached to them. Summary Section 2 – pages 175-178

Summary Section 2 – pages 175-178 Plasma Membrane The fluid mosaic model describes the plasma membrane as a flexible boundary of a cell. The phospholipids move within the membrane. Summary Section 2 – pages 175-178

Summary Section 2 – pages 175-178 Plasma Membrane Transport proteins allow needed substances or waste materials to move through the plasma membrane. Summary Section 2 – pages 175-178

Section 3 Summary – page 179-187 The Cell Wall: Aka “The Cell Wall” The cell wall is a fairly rigid structure located outside the plasma membrane that provides additional support and protection. Section 3 Summary – page 179-187

Section 3 Summary – page 179-187 The Nucleus: Aka “The Boss” Nucleolus Chromatin Nuclear Envelope Section 3 Summary – page 179-187

Section 3 Summary – page 179-187 Endoplasmic Reticulum The endoplasmic reticulum (ER) is an organelle that is suspended in the cytoplasm and is the site of cellular chemical reactions. Ribosomes ER + Ribosomes = Rough ER Section 3 Summary – page 179-187

Section 3 Summary – page 179-187 The Golgi Apparatus: aka “The Golgi Body” The Golgi packages cellular products into a vesicle and sends them out of the cell. Golgi Apparatus Section 3 Summary – page 179-187

Section 3 Summary – page 179-187 Vacuoles Vacuoles are membrane-bound spaces used for temporary storage of materials. Notice the difference between vacuoles in plant and animal cells. Vacuole Animal Cell Plant Cell Regular closet Garage Section 3 Summary – page 179-187

Section 3 Summary – page 179-187 Lysosomes Lysosomes are organelles that contain digestive enzymes. They digest excess or worn out organelles, food particles, and engulfed viruses or bacteria. Lyse = to break apart Section 3 Summary – page 179-187

Section 3 Summary – page 179-187 Chloroplasts Chloroplasts are cell organelles that capture light energy and produce food to store for a later time. The chloroplasts belongs to a group of plant organelles called plastids, which are used for storage. Chloroplasts contain a green pigment called chlorophyll. Chlorophyll traps light energy and gives leaves and stems their green color. Chloroplasts Section 3 Summary – page 179-187

Section 3 Summary – page 179-187 Mitochondria Mitochondria are membrane-bound organelles in plant and animal cells that transform energy for the cell. A mitochondria has a highly folded inner membrane. Energy storing molecules (ATP) are produced on inner folds. Inner membrane Section 3 Summary – page 179-187

Section 3 Summary – page 179-187 Cytoskeleton Cells have a support structure called the cytoskeleton within the cytoplasm. The cytoskeleton is composed of microtubules and microfilaments. Microtubules are thin, hollow cylinders made of protein and microfilaments are thin solid protein fibers. Section 3 Summary – page 179-187

Section 3 Summary – page 179-187 Cilia and Flagella Some cell surfaces have cilia and flagella, which are structures that aid in locomotion or feeding. Cilia and flagella can be distinguished by their structure and by the nature of their action. Section 3 Summary – page 179-187

Section 3 Summary – page 179-187 Cilia and Flagella Cilia Cilia are short, numerous, hair-like projections that move in a wavelike motion. Flagella are long projections that move in a whip-like motion. Flagella and cilia are the major means of locomotion in unicellular organisms. Flagella Section 3 Summary – page 179-187

Summary The Cell Theory (this is important): 1.All living things are composed of at least one cell 2. Cells are the basic unit of organization. 3. All cells come from other living cells.

Summary Cells work like little factories: they are full of membrane-bound structures, called organelles that do a variety of different jobs. Each organelle has a specific job to do, just like little factory workers…or machines. THE END…Almost

Cell Membrane Ribosomes Nuclear Envelope Nucleolus Chromatin Smooth ER Rough ER Golgi Vacuole Mitochondria Cytoplasm

Cell Membrane Cell Wall Ribosomes Nuclear Envelope Nucleolus Chromatin Smooth ER Rough ER Golgi Vacuole Chloroplast Mitochondria Cytoplasm