Cell Structure and Functioning Part 1 PDF

# Cells ## Cell Definition - The smallest unit that shows properties of life - Organelles are structures that carry out special metabolic functions inside a cell. - Tasks such as building, modifying, and storing substances. ## Simple Animal Cell - Cytoplasm - DNA - Nucleus - Nucleoid - Cel...

# Cells ## Cell Definition - The smallest unit that shows properties of life - Organelles are structures that carry out special metabolic functions inside a cell. - Tasks such as building, modifying, and storing substances. ## Simple Animal Cell - Cytoplasm - DNA - Nucleus - Nucleoid - Cell Membrane ## Types of Cells ### Eukaryotic Cells - **Definition:** Cell interior is divided into functional compartments including a nucleus. ### Prokaryotic Cells - **Definition:** Small, simple cells without a nucleus. ## Modern Microscopes - **Light microscopes** - Phase-contrast microscopes - Reflected light microscopes - Fluorescence microscopes - **Electron microscopes** - Transmission electron microscope - Scanning electron microscopes ## Prokaryotes - **Definition:** **Bacteria** and **Archaea** are prokaryotes (before the nucleus). - **Facts:** The smallest and most metabolically diverse forms of life. - **Note:** Prokaryotes are single-celled. ## Biofilm - **Definition:** Single-celled organisms sharing a secreted layer of polysaccharides and glycoproteins. - **Examples:** bacteria, algae, fungi, protists and archaeans ## Eukaryotic Cells - **Definition:** All protists, fungi, plants and animals. - **Fact:** All eukaryotic cells' DNA is in the nucleus - **Organelles:** - Cell wall - Vacuole - Plasma membrane - Mitochondrion - Nucleus - Central Vacuole - Chloroplast - Cytoskeleton - Microtubules - Microfilaments - Intermediate filaments - Plasmodesma - Plasma Membrane - Ribosomes - Rough ER - Smooth ER - Golgi Body - Lysosome-Like Vesicle ## Human White Blood Cell - **Organelles:** - Rough ER - Modifies proteins made by ribosomes attached to it. - Smooth ER - Makes lipids, breaks down carbohydrates and fats, inactivates toxins. - Golgi Body - Finishes, sorts, ships lipids, enzymes, and proteins. - Lysosome - Digests, recycles materials. - Nuclear pore ## Structure of the Nucleon Envelope - The nuclear envelope is a double lipid bilayer. - Proteins embedded in it control the passage of molecules between the nucleus and the cytoplasm. - Nuclear envelope (two lipid bilayers) ## Structure of the Nucleus - **Nucleoplasm:** Viscous fluid inside the nuclear envelope, similar to cytoplasm. - **Nucleolus:** A dense region in the nucleus where subunits of ribosomes are assembled from proteins and RNA. This protects and controls access to eukaryotic cells' DNA. - **Chromatin:** All DNA and its associated proteins in the nucleus - **Chromosome:** - A single DNA molecule with its attached proteins. - During cell division, chromosomes condense and become visible in micrographs. - Human body cells have 46 chromosomes.