Summary

This document provides a general overview of cell theory and the components of cells. It covers the basic building blocks of all living things and details crucial contributions from key scientists like Robert Hooke and Anton van Leeuwenhoek. It also delves into the structure and function of various components of cells such as the plasma membrane, cytoskeleton, cytoplasm, and cell wall.

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GEN BIO 1 (General Biology 1) Lesson 1: Cell Theory What is cell? Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. Scientists who have contributed to the development of Cell Theory Zacharias Janssen (1585-1632) - was a Dutch...

GEN BIO 1 (General Biology 1) Lesson 1: Cell Theory What is cell? Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. Scientists who have contributed to the development of Cell Theory Zacharias Janssen (1585-1632) - was a Dutch spectacle-maker who is often credited with inventing the compound microscope. Robert Hooke (1635-1703) - was an English scientist, natural philosopher, and polymath known for his significant contributions to various fields of science. - He observed cork cells under a microscope. - Examined very thin slices of cork and saw a multitude of tiny pores that he remarked looked like the walled compartments a monk would live in. Because of this association, Hooke called them cells. Francesco Redi (1626-1697) - was an Italian physician and biologist who is renowned for his pioneering work in the field of. experimental biology. - He disproved the spontaneous generation theory. Antonie van Leeuwenhoek (1632-1723) - was a Dutch merchant and scientist who is widely regarded as the father of microbiology. - He observed microorganisms by using his own practical microscope. Matthias Jacob Schleiden (1804-1881) - was a German botanist who played a crucial role in the development of cell theory, a fundamental concept in biology. - He proposed that all plants are composed of cells. Theodor Schwann (1810-1882) - was a German physiologist who founded modern histology by defining the cell as the basic unit of animal structure. Rudolf Virchow (1821-1902) - was a prominent German physician, pathologist, and reformer who made significant contributions to medical science and public health. - He proposed that all cells come from pre-existing cells. - Formulated the principle, "Omnis cellula e cellula" translates to "all cells come from cells" or "every cell originates from a cell." The three principles of cell theory 1. All living organisms are composed of cells. They may be unicellular or multicellular. Unicellular organism - composed of one cell for all of its function. Multicellular organism - composed of more than one cell that has a specialized function. Their functions: uptake and processing of nutrients excretion of wastes response to environmental stimuli and reproduction among others. 2. The Cell is the basic unit of life. It is the smallest structural and functional unit in all organisms. 3. Cell comes from pre-existing cells. Cell contain hereditary material, which they pass to their daughter cells when they divide. GEN BIO 1 (General Biology 1) Recycling center of the wall Lesson 2: Structures and Functions of Cell Vacuoles The cell is the lowest level of structure capable of Sac-like structure that store different material performing all the activities of life. Like storage bag (proteins and liquids) The first cells were observed and named by Robert Stores energy Hooke in 1665 from slice of cork. Components of the cell: Major parts of the cell Mitochondria Plasma Membrane This is known as the “powerhouse of the cell” The plasma membrane, also called the cell membrane, is Their main function is to generate the energy necessary the membrane found in all cells that separates the interior to power cells of the cell from the outside environment. The plasma membrane is the cell's primary barrier. Chloroplast Controls what goes in and out (good and bad cells) A chloroplast is a structure in a plant cell that contains Cytoskeleton large amounts of chlorophyll. The cytoskeleton is a structure that helps cells maintain It is where photosynthesis happens. their shape and internal organization. Capture sunlight and/to convert into foods and/or serve It also provides mechanical support that enables cells to as a medicine to plants carry out essential functions like division and Constant large amount of chlorophyll movement. Chlorophyll means green pigment of the plants Internal support system Frameworks (buildings) Helps reshape cells Allow cells to organize Cytoplasm Cytoplasm is the gelatinous liquid that fills the inside of a cell. It is composed of water, salts, and various organic molecules. Cytosis - liquid inside the cell Cell wall Cell wall is a rigid structure that surrounds the cell membrane. It helps maintain the shape of cells and prevent them from bursting. Components of the cell: Subcellular Organelles Genetic control of the cell nucleus and ribosomes Endomembrane system endoplasmic reticulum Golgi bodies lysosomes and vacuoles Energy houses mitochondria chloroplast Nucleus This is a prominent, usually oval structure in a eukaryotic cell. It is located in the middle of the cell If nucleus is non-existent, a cell won’t work Ribosomes Ribosomes are the organelles that use instructions from the nucleus, written in mRNA, to build proteins. (creates proteins) Ribosomes can be compared to protein making factories Tiny structures that create proteins Building blocks of ammino acids and of proteins Endoplasmic Reticulum Rough ER have thousands of ribosomes attached to the outer surface which give this organelle a “rough” appearance. Their main role is to produce proteins. Smooth ER does not have attached ribosomes. This organelle produces lipids. (no ribosomes) Golgi Body A Golgi body, also known as a Golgi apparatus, is a cell organelle that helps process and package proteins and lipid molecules, especially proteins destined to be exported from the cell Packaging and sorting center of the cell Lysosome Garbage collector that taken damage to a worn out cell parts. GEN BIO 1 (General Biology 1) Endomembrane system Lesson 3: Prokaryotes and Eukaryotes It includes the rough and smooth endoplasmic reticulum, Golgi apparatus, lysosome, endosome, and Two types of cells vacuole. Prokaryotic cell are single-celled microorganisms It is present in eukaryotic cells, but not in prokaryotic known to be the earliest on earth. cells Prokaryotic organisms are metabolically diverse because they can utilize different nutrients and energy sources and they can inhabit all types of environment Ribosome of eukaryotes Ribosome of prokaryotes on Earth All bacteria that include the organisms of domains Archaea and Bacteria are considered as prokaryotes. Ribosomes can be found in the cytoplasm, outer Archaea nuclear membrane, rough All ribosomes are found Archaea belong to the domain Archaea and are single- celled, prokaryotic organisms that do not have endoplasmic reticulum, in the cytoplasm. membrane-bound organelles and are distinct from both mitochondrion, and bacteria and eukaryotes chloroplast. Two types of Archaea Methanobrevibacter smithii - is an archaea, a type of single-celled organism that Eukaryotes have 80S doesn't have a distinct nucleus. It's one of the most common microbes living in our guts ribosomes Prokaryotes have 70S Pyrococcus furiosus (mitochondria, and - is an aquatic anaerobic hyperthermophiles archaeon ribosomes. chloroplast contain 70S first isolated in a hydrothermal vent near Vulcano Island, Italy ribosomes) Bacteria Bacteria are microscopic living organisms that have only one cell. The word for just one is “bacterium.” Millions (if not billions) of different types of bacteria Chrosomone number of Chrosome number of can be found all over the world, including in your body. eukaryotes prokaryotes They're on your skin and in your airways and mouth Two types of bacteria Escherichia coli (E. coli) - is a type of bacteria that normally lives inside our intestines, where it helps the body break down and more than one linear one covalent, closed, digest food DNA with histone circular DNA Lactobacilli - is a type of bacterium that makes lactic acid (a substance that is made from sugars found in milk and is also made in the body). They are normally found in Eukaryotes have more the mouth, gastrointestinal tract, and vagina. than one chromosome so Most prokaryotes have Two types of cell histones are essential in only one chromosome Eukaryotic cells packaging DNA into and an - are defined as cells containing organized nucleus and organelles which are enveloped by membrane-bound nucleosomes and helping extrachromosomal DNA organelles it to condense into called a plasmid. - Domain Eukarya, which includes protists, fungi, chromatin. plants, and animals, is eukaryotic Examples of protist Green algae - refer to a diverse group that predominantly inhabit freshwater environments Mushroom - is the fleshy, spore-bearing fruiting body of a fungus. It grows above ground, on soil, or on any source of food. It is considered a fungus because it contains no chlorophyll and is a saprophyte Distinguishing Feature of Prokaryotic and Eukaryotic Cells Ribosome of eukaryotes Ribosome of prokaryotes present in most eukaryotic cells (these are present in almost all not found in animals and prokaryotic cells most protists) Cell wall is either made Cell wall is made up of up of cellulose as in peptidoglycan. plants and chitin in fungi.

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