Organic Chemistry and Biochemistry Essential Concepts
Organic Chemistry and Biochemistry Essential Concepts
Obj 1 Describe organic chemistry and give examples of types of organic molecules.
Organic chemistry is the branch of chemistry that deals with compounds that contain carbon. Such compounds are referred to as organic compounds because these compounds make up the "backbone" of living systems.
Carbon is unique among elements in that it can bond to other carbon atoms to form long chains and rings. Millions of organic compounds exist. Among them are hydrocarbons (which contain only hydrogen and carbon), and polymers (large molecules made up of many smaller, repeating units), including plastics (polymers that can be molded into different shapes).
Obj 2 Describe biochemistry and four types of biomolecules
Biochemistry is the study of the chemistry of living things. Other than water, which can account for 80% or more of the weight of an organism, most of the molecules of life are organic. Biomolecules can be classified as proteins, carbohydrates, lipids and nucleic acids.
Obj 3 Compare and contrast the structures and functions of proteins, carbohydrates, lipids, and nucleic acids.
Proteins
Proteins are complex polymers made of chains of individual units called amino acids joined by bonds called peptide bonds. The many thousands of types of proteins in living systems are made up of different combinations of only twenty amino acids. These amino acids are composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. Muscles and hair are made of protein. Proteins are involved in almost everything that cells do. Enzymes, which speed up chemical reactions, are an important type of protein. Antibodies are proteins that protect against invading disease organisms. Hemoglobin is a protein in blood that transports oxygen throughout the body. Many hormones are proteins produced in one place in the body that regulate and coordinate the activities in other places.
Carbohydrates
Carbohydrates, which include sugars and starches, are molecules composed of carbon, hydrogen, and oxygen atoms. Carbohydrates are used as a main energy source for most organisms, for structure (especially in plants) and for many other functions. Glucose, a simple sugar, is used for energy in most body processes. Polymers of carbohydrates, called polysaccharides, include starch (in plants) and glycogen (in animals) which are molecules organisms use to store energy. Carbohydrates also play a structural role. Cellulose, also a glucose polymer, proves strength and support in plants. Chitin, another carbohydrate polymer, forms the hard exteriors of insects and other arthropods.
Lipids
Lipids, including fats, oils, and waxes, feel greasy and do not dissolve in water. Lipids are molecules composed of carbon, hydrogen, and oxygen (as are carbohydrates). Some, called phospholipids, contain phosphorus as well, and are the main component of cell membranes. Other lipids (fats) function as long-term energy storage molecules. Steroids are another type of lipid. Important steroids include cholesterol, some sex hormones, vitamin D, and the bile salts that are produced in the liver to aid in digestion of fats.
Nucleic Acids
Nucleic acids, including DNA and RNA, are composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus. Nucleic acids are made of chains of units called nucleotides which, in turn, are made of a sugar, a nitrogen-containing base, and a phosphate ion. Nucleic acids contain hereditary information.
Reactions of Life
Obj 4 Provide the chemical reaction that describes photosynthesis.
Photosynthesis is the process by which plants convert carbon dioxide and water into sugars that can then be either used by the plant or by heterotrophs. The general reaction, which should be memorized, is :
6CO2 + 6H2O light energy C6H12O6 + 6O2
Written out, this equation states that 6 molecules of carbon dioxide (CO2) react with 6 molecules of water (H2O) to yield, in the presence of light energy, one molecule of glucose (C6H12O6, a sugar) and 6 molecules of oxygen gas (O2).
Obj 5 Compare aerobic respiration to photosynthesis
Cellular respiration is the process by which food molecules are broken down to release energy. This is the process we use to get energy from the food we eat; in fact, all cells (plant, animal, or otherwise) respire. That is, they break complex molecules into simpler ones and use the released energy to live and grow. Aerobic respiration involves oxygen; anaerobic respiration is respiration in the absence of oxygen.
Aerobic respiration is just the opposite of photosynthesis. Oxygen is used to break up glucose (or other molecules) and carbon dioxide, water, and energy are given off.
Photosynthesis: CO2 + H2O + energy C6H12O6 + O2
Aerobic Respiration: C6H12O6 + O2 CO2 + H2O + energy
We get sugars from the foods we eat, and we inhale oxygen. We exhale carbon dioxide, excrete water and use energy to live and grow.
Obj 6 Compare and contrast alcoholic fermentation and lactic acid fermentation
Anaerobic respiration occurs in the absence of oxygen. There are two types of anaerobic respiration: alcoholic fermentation and lactic acid fermentation.
Alcoholic fermentation produces ethanol (an alcohol) and carbon dioxide and is used to ferment alcohol and when baking (it's the carbon dioxide gas given off that puffs up pastry).
Animals cells are not capable of alcoholic fermentation. Some animal cells, like our muscle cells, can respire without oxygen using a process called lactic acid fermentation. When muscles run out of oxygen, they can still work, but the result is the production of lactic acid, which we feel as fatigue and soreness.