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субота, 06. април 2013.

Proteins


Proteins are the most important biochemical molecules that consist of a large number of interconnected amino acids.Their name comes from the Greek word proteios(the first,most important),which means that the 10 essential amino acids,which are their main components,be taken in with food and they are called essential amino acids.

Proteins can be classified in several ways:

1)According to members:

a)simple proteins(consisting only of an adequate number of amino acids linked by peptide bonds to each other)

b)complex proteins(except amino acids contain some additional organic molecule-ion of Fe in the hemoglobin molecule(Hb))

2)According to the solubility of the proteins are broken down into:

a)albumins(proteins that are soluble in H20-water)

b)globulins(proteins that are dissolved in a solution of salts;NaCl-table salt)

c)prolamins(proteins soluble in ethanol-C2H5OH)

d)scleroproteins-fully insoluble proteins(for example:collagen,elastin,ceratin,which are part of the cartilage and connective tissue)

3)According to the biological function of proteins are divided into:

a)enzyme-as biocatalysts that increase the rate of chemical reactions and are characterized by a high specificity

b)reserve proteins-represent depo amino acids that is necessary uses for growth and development of embryos(example casein)

c)transport proteins-specific molecules are transferred through blood and membranes(hemoglobin carries oxygen,albumins transfer fatty acids)

d)protective proteins-have a protective function(trombin and fibrinogen-proteins involved in blood clotting)

e)hormones-regulated metabolism(metabolism is the set of all reactions in a living organism;example of mitotropes proteins hormones that regulate metabolism)

f)toxins-toxic proteins even in small amounts

g)structural proteins-build structures of different body(α ceratin,which became part of the skin,hair,nails)

петак, 05. април 2013.

Proteini


Proteini su najvažniji biohemijski molekuli koji se sastoje od velikog broja međusobno povezanih amino-kiselina.Naziv im potiče od grčke reči proteios(prvi,najvažniji),što znači da se 10 osnovnih amino-kiselina koje ulaze u njihov sastav moraju unositi hranom i nazivaju se esencijalne amino kiseline.Proteini se mogu podeliti na više načina:

1)Prema sastavu:

a)proste proteine(sastoje se samo od odgovarajućeg broja amino kiselina međusobno povezanih peptidnim vezama)

b)složeni(sem amino kiselina sadrže još i neki dodatni organski molekul-jon Fe u molekulu hemoglobina(Hb))

2)Prema rastvorljivosti proteini se dele na:

a)albumini(proteini koji se rastvaraju u H2O-voda)

b)globulini(proteini koji su rastvoreni u nekim rastvorima soli NaCl-kuhinjska so)

c)prolamini(proteini rastvorljivi u C2H5OH-etanol)

d)skleroproteini-potpuno nerastvorni proteini(npr.kolageni,elastini,keratini,koji ulaze u sastav hrskavice i vezivnog tkiva)

3)Prema biološkoj funkciji proteini su podeljeni na:

a)enzime-to su biokatalizatori koji povećavaju brzinu hemijske reakcije i odlikuju se visokom specifičnošću

b)rezervni(skladištni)proteini-predstavljaju depo aminokiselina koje se po potrebi koriste za rast i razviće embriona(npr.kazein)

c)transportni proteini-prenose tj.vezuju specifične molekule kroz krv i membrane(hemoglobin prenosi O2-kiseonik,albumini prenose masne kiseline)

d)zaštitni proteini-imaju odbrambenu funkciju(trombin i fibrinogen-proteini koji učestvuju u koagulaciji-zgrušavanju krvi)

e)hormoni-regulišu metabolizam(metabolizam predstavlja skup svih reakcija u nekom živom organizmu;primer za hormone su mitotropni hormoni koji regulišu metabolizam)

f)toksini-otrovni proteini čak i u malim količinama

g)strukturni proteini-izgrađuju različite telesne strukture(alfa keratin koji ulazi u sastav kože,kose,noktiju)

четвртак, 04. април 2013.

Amino acids


Amino acids are organic compounds whose molecules contain carboxyl(COOH) group and an amino group(NH2).The amino acid composition includes C,H,N,O(Carbon,Hydrogen,Nytrogen,Oxygen).The role of amino acids to build proteins.All the amino acids that form proteins are α-amino acids as the amino and carboxyl groups related to the same α-atom C.Amino acids are subject to almost all chemical reactions.The most important chemical reactions of amino acids to form a peptide bond that allows the connection of two amino acids and the creation of chains of amino acids.Peptide bond is a bond between the carboxyl group of one amino acid and the amino group of the other amino acids,in which the C atom of the carboxyl group linked to the N atom with the release of H2O molecules.The basic classification of amino acids in the protein and non-protein.

среда, 03. април 2013.

Aminokiseline


Aminokiseline su organska jedinjenja čiji molekuli sadrže karboksilnu(COOH) grupu i amino(NH2) grupu.U sastav aminokiselina ulaze C,H,N i O(ugljenik,vodonik,azot i kiseonik).Uloga aminokiselina je da izgrađuju proteine.Sve aminokiseline koje grade proteine su α-aminokiseline pošto su amino i karboksilne grupe vezane za isti,α-atom C.Aminokiseline podležu gotovo svim hemijskim reakcijama.Najvažnija hemijska reakcija aminokiselina je formiranje peptidne veze koja omogućava povezivanje dve aminokiseline i stvaranje lanaca aminokiselina.Peptidna veza je veza između karboksilne grupe jedne aminokiseline i amino grupe druge aminokiseline,u kojoj se atom C karboksilne grupe vezuje za atom N uz oslobađanje molekula H2O.Osnovna podela aminokiselina je na proteinske i neproteinske.

уторак, 02. април 2013.

Carbohydrates


Carbohydrates are the most common compounds in the living world.General formula of carbohydrates is Cn(H2O)n.Carbohydrates are divided into monosaccharides,disaccharides and polysaccharides.Monosaccharides are simple sugars.According to the number of Carbon atoms are broken down into monosaccharides:trioses(3C),tetroses(4C),pentoses(5C),hexose(6C) and heptoses(7C).In the fall pentoses ribose(RNA enters into the composition) and Desoxyribose(constructed DNA).The hexose glucose fall(there is fruit in the blood,is the main source of energy),fructose(fruit sugar) and galactose(there is a built in milk and lactose).Disaccharides consist of two monosaccharides.The disaccharides are malthose,lactose(milk sugar) and sucrose(sugar derived from sugar cane or beets).Polysaccharides are complex sugars.Divided into structural and reserve.Structured as cellulose(the main component of the cell wall in plants,is used to getting behind the paper) and agar(seaweed have it).Spare the starch(in plants) and glycogen(in animals).

понедељак, 01. април 2013.

Ugljeni hidrati

Ugljeni hidrati su najrasprostranjenija jedinjenja u živom svetu.Opšta formula ugljenih hidrata je Cn(H2O)n.Ugljeni hidrati se dele na:a)monosaharide,b)disaharide,c)polisaharide.Monosaharidi su prosti šećeri.Prema broju C atoma monosaharidi se dele na:trioze(3C),tetroze(4C),pentoze(5C),heksoze(6C),heptoze(7C).U pentoze spadaju riboze(ulazi u sastav ribonukleinske kiseline-RNK) i dezoksiriboze(izgrađuje DNK).U heksoze spadaju glukoza(grožđani šećer,ima je u voću i u krvi,glavni je izvor energije),fruktoza(voćni šećer) i galaktoza(ima je u mleku i gradi laktozu).Disaharidi se sastoje od 2 monosaharida.U disaharide spadaju:maltoza,laktoza(mlečni šećer) i saharoza(šećer dobijen iz trske ili šećerne repe).Polisaharidi su složeni šećeri.Dele se na strukturne i rezervne.Strukturni su celuloza(glavni sastojak ćelijskog zida kod biljaka,koristi se za dobijanje papira) i agar(imaju ga alge).Rezervni su skrob(kod biljaka) i glikogen(kod životinja).

недеља, 31. март 2013.

Fats and oils

Fats and oils participate in the construction of plant and animal organisms.These are esters of fatty acids and trihydroxil alcohol glycerol.At room temperature,fats are solid and oils are liquid.Fats do not dissolve in water and are easier then water.The composition of fats and oils(lipids) enter more fat acid(acid with a larger number of carbon atoms).The most famous were:a)palmitic acid,b)stearic acid,c)oleic acid.Structural formulas of fatty acids can be displayed zigzag formulas.Represent the broken line and any place where the line bends involves one C atom and the corresponding number of H atoms.Simple lipids are esters in chemical composition and resulting esterification reaction in which glycerol reacts with higher fatty acids.Created 3 ester links(3 links acyl) why are they called triglycerides.The concentracion of triglycerides in the blood of people is checked by analyzing blood,and depends on proper nutrition and metabolism of the person.