The_Chemistry_of_Life - The Chemistry of Life The Elements...

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Unformatted text preview: The Chemistry of Life The Elements An element the simplest form of matter Atomic numbers 91 natural elements 24 elements play a physiological role in the human body 6 elements make-up 98.5% of a human's body weight ~ Oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus ~Calcium and Phosphorous make up our bones~ *Trace elements needed in only tiny amounts* Minerals contribute to the body structure; inorganic elements passed up the food chain What is an atom? "Invisible particles" (nickname) Nucleus the center of an atom Protons and neutrons compose the nucleus Electrons surround the nucleus The outermost electrons are called valence electrons and determine the chemical behavior of an element Ions Ions "charged particles with unequal numbers of protons and electrons" (p. 59). Ionization process of transferring electrons Anion acquiring a negative charge ~gaining an electron Cation loses an electron and acquires an excess of protons Why are anions and cations important? Their attraction to each other maintains muscle and nerve cell excitability Electrolytes and Free Radicals Why do you drink Gatorade (an electrolyte)? Free radicals particles with odd numbers of electrons What have you heard about free radicals? Antioxidants a way to neutralize free radicals Antioxidant deficiency associated with heart attacks, sterility, muscular dystrophy Molecules and Compounds Molecules "chemical particles composed of two or more atoms" Compounds "molecules composed of two or more different elements" What makes water important to the body? WATER Constitutes 50-75% of our body weight Universal solvent dissolves more substances than other liquids Hydrophilic a substance that dissolves in water Hydrophobic a substance that does not dissolve in water i.e., fat Biological functions adhesion vs. cohesion *Adhesion a substance clings to another *Cohesion molecules of the same substance cling to each other Thermal stability assists in stabilizing the body's internal temperature Energy and Work What is the difference between energy and work? Energy "capacity to do work" Work "to move something" What does the body do that is work? Energy is classified as potential and kinetic Potential energy the amount of energy an object contains Chemical energy potential stored in the bonds of molecules When chemical reactions occur they release energy and make it available for physiological work Electrical energy potential and kinetic Kinetic energy energy of motion Heat from molecular motion Electromagnetic Electrical energy potential and kinetic Organic Compounds What is the versatile atom that serves as the basis of a variety of structures? What are the 4 categories of organic molecules? Carbon bonds with other atoms and form long chains of molecules Breakout groups Carbohydrate group what are carbohydrates; what are the different types of carbohydrates; give examples of each type; what important functions do carbs have; how do we get energy from carbohydrates? Lipid group what are lipids; what are the different types of lipids; give examples of the types; what important functions do lipids have; what is cholesterol and how does it relate to lipids? Protein group what are proteins; what is an amino acid; what are the different chains of amino acids; what is the basic structure of proteins; what are the functions of protein? Carbohydrates A hydrophilic organic molecule Likes water Types: monosaccharides (glucose, fructose, galactose) Dissaccharides (sucrose) Polysaccharides Carbs ~ glucose + O2 = ATP = energy Lipids Hydrophobic organic molecule Types: fatty acids, cholesterol (sterol), triglyceride Functions: help with regulating energy, digestion, form of energy, chemical messengers Proteins Long chain of molecules (amino acids) Amino acids are group of molecules with Carbon and Amino Basic structure of proteins are a primary structure, secondary structure, terchiary structure, and quandary structure Provides structure to the cell ATP Adenosine Triphosphate A nucleotide organic compound with three components nitrogenous base, a monosaccharide, and one or more phosphate groups Body's most important energy-transfer molecule Briefly stores energy and then releases it for physiological work ATP is short-lived (roughly 60 seconds) Continually replenished Important when understanding muscle How Does ATP Work? The energy for ATP synthesis comes from *glycolysis* "splitting the sugar" some ATP produced, but mostly pyruvic acid If oxygen is not available anaerobic fermentation occurs the pyruvic acid turns into lactic acid If oxygen is available aerobic respiration occurs breaks pyruvic acid down to carbon dioxide and water and generates ATP occurs in the mitochondria Nucleic Acids 19th century cytologists and biochemists looked for biochemical keys to heredity in the nucleus led to the discovery of DNA (deoxyribonucleic acid) Johann Miescher guessed that DNA was the herditary matter but did not have strong evidence for his belief DNA regulates cell form and function DNA vs RNA DNA deoxyribonucleic acid 100 million to 1 billion nucleotides long Constitutes our genes Transfers hereditary information from cell to cell when they divide Gives instructions for synthesizing the body's proteins RNA ribonucleic acid 70-10,000 nucleotides long Carry out the instructions and synthesize proteins Assemble amino acids in the right order to produce proteins DNA Structure and Function Approximately 46 molecules of DNA in a human cell The structure resembles a ladder that can be twisted like a spiral staircase DNA is a nucleic acid which is a nucleotide (consists of a sugar, a phosphate group, and a single or double-ringed nitrogenous base Function is to serve as a code for synthesis of RNA and polypeptides (a chain of more than 10-15 amino acids) Works in the nucleus RNA Ribonucelic acid Three types Messenger RNA, ribosomal RNA, and transfer RNA RNA is smaller than DNA contain one nucleotide chain, not a double helix like DNA Function to interpret the DNA code and direct protein synthesis Mainly works in the cytoplasm ...
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This note was uploaded on 04/07/2008 for the course HLTH 128 taught by Professor Preische during the Spring '08 term at Lock Haven.

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