16 résultats pour "amino"
-
Définition:
AMINO-, élément préfixe.
Gustave Roussy dans Fernand Widal, Pierre-Jean Teissier, Georges-Henri Roger, Nouveau trait? de m?decine, fascicule 5, 1920-1924, page 450) aminoplastes, substantif masculin pluriel. " mati?res plastiques contenant des groupements amin?s " (Dictionnaire des sciences (E.B. UVAROV, D.R. CHAPMAN) 1956); (Confer Jean Campredon, Le Bois, 1948, page 90) aminoxyde, substantif masculin. " nom g?n?rique de compos?s organiques azot?s, de formule g?n?rale R3 NO " (Grand Larousse encyclop?dique en dix v...
- Amino Acids - chemistry.
-
07/11/2011
Acides aminés et dérivés
Définition :
Dérivés bifonctionnels - fonction acide carboxylique
- fonction amine
Seulement 20 (21) amino acides naturels entrent dans la composition des
protéines, traduits du code génétique supporté par les acides nucléiques
Dans certains cas, des acides aminés pourront - après formation de la protéine -
subir des modifications dites post translationnelles
La composition en AA des protéines matures est donc un peu plus complexe
1
Structure
07/11/2011 2 Chiralité des aminoacides les trois groupements communs aux amino acides ont toujours la même localisation, quelle que soit la nature de la chaîne latérale R O R C C N H H C O C O 3 O C H NH C H N H2 COOH H NH2 COOH H NH2 COOH H N H2 COOH R S R S GM GP Chiralité des aminoacides S H SH OH O H (L) sérine (L) cystéine Tous les aminoacides naturelschiraux appartiennent à la série L, Cependant on constate que la (L) alanine est (S) alors que la (L) cystéine est...
-
Human Nutrition.
is one of the most preventable types of cancer. Nutritionists caution that most Americans need to eat more complex carbohydrates. In the typical American diet, only 40 to 50 percent of total calories come fromcarbohydrates—a lower percentage than found in most of the world. To make matters worse, half of the carbohydrate calories consumed by the typical American comefrom processed foods filled with simple sugars. Experts recommend that these foods make up no more that 10 percent of our diet, bec...
-
Metabolism (chemistry) - biology.
nearly perfect balance. Although much remains to be revealed about metabolic processes, biochemists now agree that regulatory, or rate-limiting, enzymes figure largely in the reactionsinvolved ( see Enzyme). Affecting metabolic pathways at the earliest steps, each enzyme molecule has a specific, or active, site that matches, or “fits,” its particular substrate—the compound with which the enzyme forms a product. The precision with which rate-limiting enzymes and substrates join to set off a parti...
-
Cell (biology) - biology.
proteins, or other proteins required by the cell. While relatively simple in construction, prokaryotic cells display extremely complex activity. They have a greater range of biochemical reactions than those found in theirlarger relatives, the eukaryotic cells. The extraordinary biochemical diversity of prokaryotic cells is manifested in the wide-ranging lifestyles of the archaebacteria andthe bacteria, whose habitats include polar ice, deserts, and hydrothermal vents—deep regions of the ocean un...
- aminés, acides 1 PRÉSENTATION aminés, acides, composés organiques contenant le groupe amino (8 2 NH2) et le groupe carboxyle (8 COOH), qui sont les constituants fondamentaux des protéines.
-
Digestive System.
The stomach, located in the upper abdomen just below the diaphragm, is a saclike structure with strong, muscular walls. The stomach can expand significantly to storeall the food from a meal for both mechanical and chemical processing. The stomach contracts about three times per minute, churning the food and mixing it with gastricjuice. This fluid, secreted by thousands of gastric glands in the lining of the stomach, consists of water, hydrochloric acid, an enzyme called pepsin, and mucin (the...
-
-
Vitamin.
Vitamin B 1, or thiamine, promotes the metabolism of carbohydrates, enabling these nutrients to release their energy. Thiamine also plays a role in the functioning of the nervous system, muscles, and heart. The body does not store thiamine and people who are malnourished may develop thiamine deficiency. Mild thiamine deficiency cancause fatigue, muscle weakness, and loss of appetite. Severe thiamine deficiency causes beriberi, a disease characterized by muscle weakness, swelling of the heart,and...
-
Astrobiology - astronomy.
water to help reactions along. American chemists Stanley Miller and Harold Urey tested part of Oparin and Haldane’s hypothesis in the early 1950s by simulating conditions of the early Earth. In whathas become known as the Miller-Urey experiment, the two scientists connected two flasks with a loop of glass tubing that allowed the gases to pass between the flasks.They filled the upper flask with methane, ammonia, and hydrogen—components thought to have been in the early atmosphere. They filled the...
-
Code genetique
suite des bases dans la molecule d'ADN, qui se traduit en Glair dans la suite des amino-acides de la proteine. 5 Un systeme de notation commode permet d'eclairer cette correspondance. Si les quatre bases de I'ADN sont designees par leurs initiales (A pour aneine, T pour thy- mine, G pour guanine et C pour cytosine) et les vingt amino-acides des proteines par leur premiere syllabe (cys, glu, leu, asp, pro, etc.) le code genetique est le diction- naire qui traduit une suite telle que ATGCGTAAC......
-
Acides aminés et dérivés
07/11/2011 2 Chiralité des aminoacides les trois groupements communs aux amino acides ont toujours la même localisation, quelle que soit la nature de la chaîne latérale R O R C C N H H C O C O 3 O C H NH C H N H2 COOH H NH2 COOH H NH2 COOH H N H2 COOH R S R S GM GP Chiralité des aminoacides S H SH OH O H (L) sérine (L) cystéine Tous les aminoacides naturelschiraux appartiennent à la série L, Cependant on constate que la (L) alanine est (S) alors que la (L) cystéine est...
-
Acides aminés et dérivés
07/11/2011 2 Chiralité des aminoacides les trois groupements communs aux amino acides ont toujours la même localisation, quelle que soit la nature de la chaîne latérale R O R C C N H H C O C O 3 O C H NH C H N H2 COOH H NH2 COOH H NH2 COOH H N H2 COOH R S R S GM GP Chiralité des aminoacides S H SH OH O H (L) sérine (L) cystéine Tous les aminoacides naturelschiraux appartiennent à la série L, Cependant on constate que la (L) alanine est (S) alors que la (L) cystéine est...
-
Protein.
Myosin, the protein chiefly responsible for muscle contraction, combines with actin, another muscle protein, forming actomyosin, the different filaments of whichshorten, causing the contracting action. VI GLOBULAR PROTEINS Unlike fibrous proteins, globular proteins are spherical and highly soluble. They play a dynamic role in body metabolism. Examples are albumin, globulin, casein,hemoglobin, all of the enzymes, and protein hormones. The albumins and globulins are classes of soluble proteins a...
-
Deoxyribonucleic Acid - biology.
bacterium Escherichia coli . In 1998 scientists achieved the milestone of sequencing the complete genome of a multicellular organism—a roundworm identified as Caenorhabditis elegans . The Human Genome Project, an international research collaboration, was established to determine the sequence of all of the 3 billion nucleotide base pairs that make up thehuman genetic material. In 2003 scientists completed the sequencing of the human genome. The project identified nearly all of the estimated 20...
-
Genetics - biology.
construct identical buildings. Just as each contractor would require a full copy of the blueprint to construct a complete building, each new cell needs a complete copy ofan organism’s genetic information to function properly. Organisms use two types of cell division to ensure that DNA is passed down from cell to cell during reproduction. Simple one-celled organisms and other organisms thatreproduce asexually—that is, without the joining of cells from two different organisms—reproduce by a proces...