1. Proteins Lucie Kubalová

2. A protein (in Greek πρωτεϊνη = first element ) is a complex, high molecular weight organic compound that consists of amino acids joined by peptide bonds. is essential to the structure and function of all living cells and viruses. Many proteins are enzymes or subunits of enzymes.

3. A peptide bond  is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H 2 O). This is a dehydration synthesis reaction, and usually occurs between amino acids.

4. Primary Structure  A protein can be considered to have primary, secondary, tertiary, and quaternary structures.  primary structure: the linear amino acid sequence of a protein

5. Secondary rregular (pravidelný) repeating structures arising (vznikají) when hydrogen bonds between the peptide backbone amide hydrogens and carbonyl oxygens occur at regular intervals within a given linear sequence (strand) of a protein (as in the alpha helix) or between two adjacent strands (as in beta sheets and reverse turns)

6. Tertiary tthe overall three dimensional shape of a protein, often represented by a backbone trace

7. Quaternary  oligomeric structure of a multisubunit protein in which separate proteins chains associate to form dimers, trimers, tetramers, and other oligomers. The different chains in the oligomers may be the same protein (homooligomers) or a combination of different protein chains (heteroliogomers). The different chains within the oligomer may be held together by noncovalent intermolecular forces or may also contain covalent interchain disulfides. held(hold) = držet

9. Protein nutrition in humans  proteins come in two forms: complete proteins contain all eight of the amino acids (threonine, valine, tryptophan, isoleucine, leucine, lysine, phenylalanine, and methionine) that humans cannot produce themselves, while incomplete proteins lack or contain only a very small proportion of one or more  Humans' bodies can make use of all the amino acids they extract from food for synthesizing new proteins, but the inessential ones themselves need not be supplied by the diet, because our cells can make them ourselves. proportion = podílsupply = zásobovat

11. References:  http://en.wikipedia.org  http://www.healthepic.com  http://employees.csbsju.edu

12. Thank you very much for your kind attention