* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Proteins
Survey
Document related concepts
Expression vector wikipedia , lookup
Ancestral sequence reconstruction wikipedia , lookup
Interactome wikipedia , lookup
Magnesium transporter wikipedia , lookup
Ribosomally synthesized and post-translationally modified peptides wikipedia , lookup
Nitrogen cycle wikipedia , lookup
Point mutation wikipedia , lookup
Peptide synthesis wikipedia , lookup
Western blot wikipedia , lookup
Protein–protein interaction wikipedia , lookup
Two-hybrid screening wikipedia , lookup
Nuclear magnetic resonance spectroscopy of proteins wikipedia , lookup
Metalloprotein wikipedia , lookup
Genetic code wikipedia , lookup
Amino acid synthesis wikipedia , lookup
Biosynthesis wikipedia , lookup
Transcript
Proteins Proteins What Are Proteins? Proteins are biomolecules that are made of C, O, H, N and S. The building blocks of proteins are amino acids. What are amino acids? An amino acid is a molecule that has an carboxyl group and an amino group. R represents the radical or rest of the molecule. Variable group amino group carboxylic acid group hydrogen There are 20 different amino acids. Out of the 20, 8 are called essential. Essential amino acids are amino acids that the human body cannot make (we do not have the enzymes to produce them, thus we have to ingest them as part of our food). Why? Because we need them to make our own proteins. Cells link amino acids together by dehydration synthesis The bonds between amino acid monomers are called peptide bonds The bond between an amino group of one amino acid and the carboxyl group of another amino acid makes a peptide bond. What is missing in this equation? Fill in the missing factors. Amino Acid Amino Acid Peptide Bond Many amino acids are group together in a long amino acid chain, this is called a polypeptide chain. The primary structure of a protein is its unique sequence of amino acids. The secondary structure of a protein is the folding pattern of the polypeptide chain. Two typical shapes of secondary structure are coils (an alpha helix) or folds (beta pleated sheets). Amino acid Primary structure chain Secondary structure Alpha helix Pleated sheet The tertiary structure of a protein is its “packing pattern”. This is the active form of the protein. The quaternary structure of a protein is a complex association of several polypeptide chains. Each of these polypeptide chains have a primary, secondary and tertiary structure. Collagen (gives your skin its strength) is formed by several chain making like a rope. Hemoglobin (transports oxygen) is another example of quaternary structure protein. Primary structure Amino acid Secondary structure Hydrogen bond Alpha helix Pleated sheet Tertiary structure Polypeptide (single subunit of transthyretin) Quaternary structure Transthyretin, with four identical polypeptide subunits Denaturing is breaking the weak bonds that keep the tertiary structure together. Heat, Ph and high salt are factors that may denature proteins. Denaturing inactivates the protein. Denaturing can be reversible. Functions in humans Proteins are involved in cellular structure Enzymes movement defense transport Communication Regulation. The LEGUMES Legumes are members of the bean family Fabaceae – they are dicots. Legumes is synonymous with pod, the fruit Examples of legumes: peas, beans, soybeans, peanuts, lentils, clover, alfalfa Importance of legumes Human nutrition: important sources of Protein (bean, soybean, pea, peanut, etc.) Oil (soybean, peanut, etc.) Also, legumes are the major nitrogen fixers Legumes have nitrogen-fixing bacteria in their roots, in a symbiotic relationship Bacteria take Nitrogen from air, and make it usable for the plant – the Nitrogen Cycle Legumes in the Nitrogen Cycle Nitrogen-fixing bacteria (Rhizobium) convert atmospheric nitrogen (N2) into ammonia (NH3), which reacts with water to produce ammonium (NH4+) Nitrogen-fixing bacteria live in symbiosis in roots of legumes, forming root nodules Plants convert this nitrogen into proteins or other nitrogen compounds, which are then consumed by animals Legume roots Bacteria provides nitrogen to the plant Plant provides carbohydrates to the bacteria Features of Legumes Legumes are mostly herbaceous (not woody) Usually have compound leaves Mostly annuals, some perennials Flowers are irregular, with bilateral symmetry Bees pollinate them, triggers stamens Legume seed and fruit Legume seeds are usually large, they have two large cotyledons (seed leaves) – dicot Cotyledons are filled with stored food, which helps the seed to germinate Legumes for food and forage Some examples of legumes used for food are: Beans Peas Peanut Soybean Examples of legumes used for forage, animal feed: Alfalfa Clover Vetches Bean (Phaseolus vulgare) Bean come in different genera and species Native to Mexico and the Andes in S. America Beans are very rich in protein (25%) and some carbohydrates Hundreds of species and varieties: pinto, navy, black, kidney, lima, pink, red, broad, fava, white, and mung bean Why do beans give you gas? Beans have complex carbohydrates that are indigestible by humans… These go down to the intestines, where bacteria go crazy eating these carbohydrates… As a result, the bacteria start producing methane gas, which accumulates and… you know the rest! To avoid this: rinse beans well, cook them long; treat with enzymes like “Beano” –helps to eliminate and break down these complex carbs. Peas (Pisum sativum) Pisum sativum is the common garden pea Originated in the Near East Rich in protein and carbohydrates Many varieties, including snow peas (where immature pod is eaten whole); Green peas, split peas, Chick peas (garbanzos) Lentils Peanut (Arachis hypogaea) The peanut is native to South America, cultivated by the Aztecs… later introduced to Africa, U.S., Asia, etc. Rich in oil and protein Very unusual growth pattern: peanuts sow their own seeds! Upon fertilization, ovary grows down, buries ovules into the ground, where pods mature into the peanut fruit Peanuts are called “ground nuts” Peanut uses Half of US peanut crop production is for peanut butter Also for snack foods, candy, peanut oil, animal feed Dr. George Washington Carver (1865-1943); brilliant scientist, agriculturist at Tuskegee Institute in Alabama; discovered 325 uses for peanuts! Soybean (Glycine max) Native to China, but now grown worldwide Rich in oil and protein. Uses: Cooking oil, salad dressings, mayonnaise, marg. Protein to make textured vegetable protein (TVP) as meat substitute, as animal feed Soy sauce: fermented soybeans and grain Tofu: soy milk curds Miso: fermented soybean and rice paste (Japan) Soybeans eaten as sprouts, snacks, health food Oil used to make diesel fuel, plastics, paint, ink Forage legumes Worldwide, some legumes are grown as pasture or forage crops: their high protein content makes them ideal as animal food. Alfalfa (Medicago sativa) is grown extensively as animal feed Trifolium species; true clovers, are also grown as pasture – some are now grown with other crops to provide nitrogen and protect the soil Vicia – vetches are planted to prevent soil erosion