The elemental composition and characteristics of proteins are briefly described

The basic building block of proteins is cho

Some of n contain p and.

s。The functional characteristics of proteins are: transport function, regulatory function, immune function, regulatory function and constituent structural substances.

1. Element composition: element composition.

C, H, O, N, and some p, s, etc.; Monomeric amino acids.

There are about 20 species, 8 essential and 12 non-essential.

2. Element composition: all proteins contain carbon (50-60%), hydrogen (6-8%), oxygen (19-24%), and nitrogen (13-19%); Most proteins contain sulfur (less than 4%); Some proteins contain phosphorus; A few proteins contain metallic elements (e.g., iron, copper, zinc, manganese, etc.); Individual proteins contain iodine.

3. Structural characteristics: Protein is formed by dehydration and condensation of multiple amino acid molecules, containing multiple peptide bonds.

of chemical compounds, called polypeptides. Polypeptides have a chain-like structure and are called peptide chains.

A protein molecule contains one or several peptide chains. Due to the different types, numbers, and order of amino acids that make up proteins, the spatial structure of peptide chains is very different, so the structure of protein molecules is extremely diverse.

4. Protein function: The structural diversity of a protein determines its specificity and functional diversity.

Important substances that make up cells and organisms: such as cell membranes.

proteins in chromosomes, muscles;

Some proteins have catalytic effects: such as various enzymes;

Some proteins have a transport role: such as hemoglobin. carrier proteins;

Some proteins have a regulatory effect: such as insulin and growth hormone. Wait;

Some proteins have immune effects: such as antibodies.

Structure Elemental composition C, H, O, N, and some P, S, FE, ZN, CU, B, MN, I and other monomers Amino acids (about 20 kinds, 8 essential kinds, 12 non-essential kinds) Chemical structure A compound formed by the dehydration and condensation of multiple amino acid molecules and containing multiple peptide bonds is called polypeptide. Polypeptides have a chain-like structure and are called peptide chains. A protein molecule contains one or several peptide chains.

Higher order structure Polypeptide chains form different spatial structures, divided.

Level 2, 3, 4. Structural characteristics Due to the different types, numbers and order of amino acids that make up proteins, the spatial structure of peptide chains is very different, so the structure of protein molecules is extremely diverse. Functional The structural diversity of a protein determines its specificity and functional diversity.

1 Important substances that make up cells and organisms: such as cell membranes, chromosomes, proteins in muscles; 2 Some proteins have catalytic effects: such as various enzymes; 3 Some proteins have a transport function:

Such as hemoglobin, carrier proteins; 4. Some proteins have regulatory effects: such as insulin, growth hormone, etc.; 5 Some proteins have immune effects: such as antibodies.

Note The bond (—nh—co—) that connects two amino acid molecules is called a peptide bond. The common structural characteristics of various proteins (general formula): 1 Each amino acid contains at least one amino group and one carboxyl group together with a carbon atom; 2 The difference between various amino acids is the difference in the R group.

Denaturation (Cooked Eggs) Salting Out Coagulation (Tofu) Calculation When a peptide chain formed by n AA encloses a cyclic protein, water peptide bonds are produced n; When n aa form a peptide chain, a water peptide bond n 1 is produced; When n aa form m peptide chains, water peptide bonds n m are produced; When n AAs form m peptide chains, the average molecular weight of each AA is , then the molecular weight of the resulting protein is n n m) 18