Contents
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Composition of cellular membranes
- phospholipids
- proteins
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Benefits of compartmentalization for the cell
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Differences between prokaryotes and eukaryotes
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Roles and functions of the parts of the cell
Deep Dive
- phospholipids
- FRAP
Inner workings of cells
Lets focus on this rolling macrophage that sticks to the endothelial cells that line the blood vessels by adhering to proteins. It is almost like molecular velcro. The surface of the cell is remarkably dynamic, with membrane proteins that form connections with other cells, and respond to external signals.
Macrophage: a type of immune cell that plays in important role in the body's defense against infections and other harmful substances. Origin: Macrophages are derived from white blood cells called monocytes, and are found in many tissues throughout the body, including the spleen, liver, lungs, and lymph nodes. Functions: phagocytosis, produce cytokines, and presenting foreign antigens to other immune cells (such as T cells). Macrophages are involved in tissue repair and remodeling, and they can produce growth factors that promote the growth and repair of damaged tissues. Additionally, they play a role regulating inflammation, which is the body's response to injury or infection, and the can help resolve inflammation once is has served its purpose. Phagocytosis: the process of engulfing and destroying foreign particles, such as bacteria and viruses. Cytokine: chemical messengers that help to coordinate the immune response. Monocytes: a type of white blood cell. Pathogen: is a biological agent, such as a virus, bacterium, fungus, parasite, or prion, that causes disease in its host. Pathogens, can infect a wide range of organisms. Types of diseases: viruses and bacteria can invade and multiply within the cells of their host, causing cellular damage and tissue destruction. Others, such as parasites can live within the body of their host, and feed on its nutrients, causing weakness, anemia, and other symptoms. Transmission: direct contact from host-to-host, airborne droplets, contaminated food and water, and through insect bites. Once it enters a host, it can evade the immune system and cause disease by producing toxins, damaging tissues, or hijacking the host's cellular machinery. Microbiology: the study of pathogens and the diseases they cause. Bacteria: unicellular microorganism that is found in virtually every environment on Earth, including soil, water, air, and living organisms. They are prokaryotic cells. Classification: shape, size, and biochemical characteristics. Spherical or rod-shaped, spiral or corkscrew-shaped. Can be categorized based on their ability to survive in different environments, their metabolic pathways, and their response to oxygen. Roles: important in many ecological processes, such as nutrient cycling and decomposition. Used in a variety of industrial and medical applications, such as producing antibiotics, vaccines, and enzymes for use in food production. Prokaryotic cells: cells lacking a true nucleus and other membrane bound organelles. Endothelial cells: Enzyme: a type of protein that acts as a biological catalyst to increase the rate of a chemical reaction. Enzymes are essential for the proper functioning of living organisms, as they allow biochemical reactions to occur quickly and efficiently at body temperature and pressure. Useful in: for example, Vitamin D is activated by two protein enzyme hydroxylation steps, the first in the liver and the second in the kidneys. Proteins: a large, complex molecule that is composed of chains of amino acids. Proteins are essential to the structure and function of all living organisms. Role: catalyzing chemical reactions, transporting molecules, providing structure and support to cells and tissues, and serving as signaling molecules. Membrane proteins: Catalyst: a substance that increases the rate of a chemical reaction without being consumed or permanently altered in the process. Catalysts work by providing an alternative pathway for the reaction to occur, with a lower activation energy, which allows the reaction to occur more easily and quickly. Types: either homogeneous or heterogeneous, depending on whether they are in the same phase as the reactants or in a different phase. They can also be biological or non-biological. In biological systems, enzymes are examples of biological catalysts that catalyze chemical reactions in living organisms. Usages: Used in a variety of industrial processes, such as the production of chemicals, fuels, and polymers. They are also used in automobile exhaust systems to reduce emissions of harmful gases, such as nitrogen oxides and carbon monoxide. Catalysts can be designed and optimized to improve the the efficiency of a reaction, to reduce waste, and minimize the use of energy and resources. The use of catalysts is an important strategy in green chemistry, which seeks to develop chemical processes that are environmentally friendly and sustainable. Chemical reaction: a process in which one or more substances, called reactants, are transformed into one or more different substances, called products. In a chemical reaction, the atoms of the reactants are rearranged to form new bonds and new chemical compounds. Classification: reactions can be categorized based on their type.
- Synthesis reactions, in which two or more substances combine to form a single compound.
- Decomposition reactions, in which a single compound is broken down into two or more simpler substances.
- Single-displacement reactions, in which an element or ion in a compound is replaced by a different element or ion
- Double-displacement reactions, in which two compounds exchange ions to form two new compounds.
- Combustion reactions, in which a substance reacts with oxygen to produce heat, light, and new compounds.
Description: chemical reactions can be described using chemical equations, which represent the reactants and products and the stoichiometry of the reaction. Chemical equations must obey the law of conservations of mass. Relevance: fundamental in many natural and artificial processes, including metabolism, photosynthesis, corrosion, combustion, and many others. Important for the development of new materials, drugs, and technologies, and for addressing challenges in energy, the environment, and human health. Law of conservation of mass: states that the total mass of the reactants and products must be equal. (Lavoisier: "Rien ne se perd rien ne se gagne, tout se transforme") Chemical compound: is a substance composed of two or more different elements, chemically combined in a fixed ratio. Chemical compounds have unique physical and chemical properties that are different from those of the elements that make them up (emergent properties). The atoms in a compound are held together by chemical bonds, which are formed by the sharing or transfer of electrons between atoms. A chemical compound is a substance composed of two or more different elements, while a molecule is the smallest particle of a compound that retains its properties. All compounds are molecules, but not all molecules are compounds. Some molecules, such as diatomic molecules like oxygen (O2) or hydrogen (H2), are not compounds because they are composed of only one element. Other molecules such as water (H2O) or carbon dioxide (CO2) are compounds because they are composed of two or more different elements. Molecule: the smallest particle of a compound that retains its chemical and physical properties. A molecule is formed by the combination of two or more atoms held together by covalent bonds. Molecules can be composed of one or more elements, and they can be either simple or complex, depending on the number and arrangement of atoms. Covalent bond: is a type of chemical bond formed between two atoms that involves the sharing of electrons. In a covalent bond, two atoms come together and share one or more pairs of valence electrons in order to achieve a more stable electron configuration. Covalent bonds can occur between atoms of the same element, as in the case of diatomic molecules like oxygen (O2) and hydrogen (H2) or between atoms of different elements, as in the case of molecules like water (H2O) or methane (CH4). In a covalent bond, the electrons are shared by the atoms in a way that allows both atoms to attain a full outer shell of electrons, which makes them more stable and less reactive. Types: covalent bonds can be polar or non-polar, depending on the electronegativity difference between the two atoms involved in the bond. Role: structure and function of many molecules, including those involved in biological processes such as DNA, proteins, and carbohydrates. Polar covalent bond: the electrons are not shared equally between the two atoms, resulting in a partial positive charge on one atom and a partial negative charge on the other. Non-polar covalent bond: the electrons are shared equally between the two atoms, resulting in a neutral charge distribution.