Cell Biology Revision Notes PDF

Okay, here is the converted text from the images and documents you sent, formatted in Markdown. ### Cells * Inter-cellular space - movement of gases and water between cells. * Chloroplast - photosynthesis. * Cell wall - strength and shape. * Rough endoplasmic reticulum - collects and trans...

Okay, here is the converted text from the images and documents you sent, formatted in Markdown. ### Cells * Inter-cellular space - movement of gases and water between cells. * Chloroplast - photosynthesis. * Cell wall - strength and shape. * Rough endoplasmic reticulum - collects and transports proteins. * Ribosomes - make proteins. * Cytoplasm - body of cell where chemical reactions occur. * Vacuole - stores water, metabolic waste products, and pigments. * Smooth endoplasmic reticulum - transports proteins. * Plasmalemma - controls entry of substances into the cell. * Mitochondrion - makes energy through cellular respiration. * Dictyosome - collects and transports proteins. * Nucleus - controls metabolism and holds genes. * Nuclear membrane - forms the Nucleus and protects DNA. * Nucleolus - region where DNA makes RNA for protein manufacture. * Chromatin network and nucleoplasm - chromatin network made of DNA, contains genes (hereditary information); nucleoplasm which surrounds DNA in the nucleus. * Nucleopore - movement of substances in and out of the nucleus. ### Cell Wall (Plants Only) The cell wall is a rigid non-living layer that is found outside the cell membrane, and surrounds the cell. * Plants, bacteria, and fungi all have cell walls. * In plants, the wall is comprised of cellulose. * Cellulose consists of 3 layers that help support the plant. These layers include: * Middle lamella * Primary cell wall * Secondary cell wall Here is a description of the diagram: There are three plant cells pictured, each surrounded by a cell wall. The cell wall is broken down into three parts, starting with the outside of the cell wall as the middle lamella, then the primary wall, followed by the secondary wall, and finally the plasma membrane. ### Functions of a Cell Wall 1. Protection & Support * Protects the inner parts of the plant cell. * Gives the plant a regular shape and supports the plant body. 2. Permeability * Allows water & mineral salts to pass through, distributing nutrients throughout the cells. 3. Plasmodesmata (Opening in cell wall) * Connects neighboring cells, enabling communication and transport of molecules between them. ### Cell Membrane The cell membrane, also called the plasma membrane, physically separates the intracellular space (inside the cell) from the extracellular environment (outside the cell). * The cell membrane surrounds and protects the cytoplasm. Between them is a structure known as Fluid Mosaic Model Each Phospholipid molecule has: * A hydrophilic (water attracting) head. * A hydrophobic (water repelling) tail. The Phospholipid molecules are arranged tail-tail, so that the hydrophilic heads face outwards and the hydrophobic tails are projected. Here is a description of the diagram: The image illustrates the cell membrane which is made up of; carbohydrates, protein, cholesterol, hydrophobic lipid tail, channel protein, integrals protein, peripheral protein, carrier protein, and phospholipid bi-layer and hydrophilic phosphate head. ### Optical Parts * Eyepiece * Objectives They consist of lenses that refract light to magnify the specimen ### Mechanical Parts * Clips: Holds the slide in place * Base: Provides stability * Arm: Used for carrying and support * Focusing knob: Adjust focus * Body tube: Supports the eyepiece and prevents stray light from distorting the image. ### Illuminating Parts * Mirror * Diaphragm * Condenser Their primary function is to focus light on the specimen for clear viewing. * Anton Von Leeuwenhoek (1632-1723) * Made a very powerful single-lense MS. * First to see bacteria, yeast/tiny organisms in water. * Called them "animalcules". * Robert Hooke (1635-1703) * Invented the compound MS with 2 lenses. * First to use the word "cell" after looking at a cork. * Max Knott & Errist Ruska (1931) * Created the electron MS, which uses electrons instead of light. * Can magnify up to 1 million times, but can't look at living things. Two types: * TEM: Shows 2D images of inside structures. * SEM: Shows 3D images of surfaces.