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Structure and function of proteins - Coggle Diagram
Structure and function of proteins
Common structure of amino acids
NH2-CHR-COOH
amino group, NH2
carboxyl group,COOH
R (side chain)
Classification of amino acids according to the
chemical nature of the side chain
Aliphatic amino acids
Mono amino mono carboxylic acids
• Simple amino acids: Glycine, Alanine
Glycine acts as a signaling agent in the central nervous system and helps regulate bodily functions such as movement and sensory perception.
Alanine supports liver function. Alanine is used to make the glucose the body needs. Alanine increases the metabolism of alcohol.
• Branched chain amino acids: Valine, Leucine, Isoleucine
All three of them cannot be created by the body. must be obtained from eating It is a component in the protein molecule of meat (meat).
• Hydroxy amino acids: Serine, Threonine
Threonine is an amino acid that cannot be synthesized by the body itself. must be obtained from food therefore classified as essential amino acids
Serine is an amino acid that can be synthesized by the body. classified as non-essential amino acids
• Sulphur containing amino acids: Cysteine, Methionine
Methionine plays an important role in helping to prevent the accumulation of fat in the liver. and help prevent depression
Cysteine is not a non essential amino acid because the body can make it on its own from methionine.
• Amino acids with amide group: Asparagine, Glutamine
Asparagine is an amino acid that can be synthesized by the body. It is classified as a non-essential amino acid.
Glutamine is responsible for removing excess ammonia. which is a waste of the body to help
immune system function brain function and the digestive system to be normal and helps to heal wounds
Mono amino dicarboxylic acids: Aspartic acid, Glutamic acid
Aspartic acid is an important component of aspartame, a low-calorie sugar substitute.
Glutamic acid is monosodium glutamate
Di basic mono carboxylic acids: Lysine, Arginine
Lysine is very important in helping to build proteins that are important to the body. The body therefore needs this amino acid to help it grow. Enhance immunity, hormones, enzymes, including tissue repair.
Arginine stimulates the body to produce Nitric Oxide (Nitric Oxide) to help with the expansion of blood vessels. as well as stimulating the secretion of Growth Hormone, which is an important hormone in maintaining youth help slow down aging pure arginine Very soluble in water and has the property of being a positively charged base
Aromatic amino acids: Phenylalanine, Tyrosine
Phenylalanine It is a precursor to the synthesis of chemicals in the nervous system. The neurochemical, when created, will make you feel comfortable, happy, and emotional.
Tyrosine is a precursor in the enzymatic browning reaction.
Heterocyclic amino acids: Tryptophan, Histidine
Tryptophan is a natural essential amino acid drug. which the body cannot produce by itself But it is found in high protein foods and milk. It works to help people stabilize their mood by restoring chemicals in the brain. Used as an adjunct to the treatment of depression.
Histidine is a precursor to the production of histamine, a toxic substance. is scombrotoxin
Imino acid: Proline
Natural moisturizing factor (NMF) that keeps skin hydrated. amino acids for skin and hair
Structure of proteins
2.Secondary structure
2.1 Alpha-helix It's a polypeptide line. with a rigid rodlike structure formed by the winding of polypeptide strings at the -CO group
2.2 Beta-pleated sheet is a structure that the polypeptide line that are close to each other will be captured
with hydrogen bonds
2.3 Reverse turns (beta-bends or hairpin bends) are an important part of the structure.
The second degree occurs on the surface of globular proteins.
Tertiary structure
Tertiary structure is the 3D structure of the polypep.
Tide formed by the folded folds of the secondary structure. resulting in a more stable structure and
functional (native form). Each area where the curl occurs is called domains.
Primary structure is a protein that has a linear structure.
obtained from new synthesis
4.Quaternary structure
Many proteins, especially those with high molecular weights.
Amino Acid Derivatives
The amino acids in the polypeptide chain that cells synthesize may be modified in some groups, for example 4-hydroxyproline (4-hydroxyproline) and 5-hydroxyli. Scene (5-hydroxylysine) is found in collagen, the most common protein in mammalian bodies.
The amino acids that make up protein histones that bind to the DNA strand (DNA) in cells may be added to the methyl, acetyl or phosphate group.
The gamma-carboxyglutamic acid, which is a component of many proteins involved in blood coagulation, is also modified from basic amino acids.
4-Hydroxyproline
hydroxyproline It is a derivative of amino proline acid. which are found as constituents in the molecules of collagen and gelatin
The synthesis of hydroxyproline is based on vitamin C. Therefore, a lack of vitamin C weakens the collagen fibers. easily injure which is one characteristic of scurvy
3-methylhistidine
3-Methylhistidine (3-MH) is a post-translationally modified amino acid which is excreted in human urine
3-Methylhistidine is a metabolic product that is produced in the body via the enzymatic methylation of histidine during peptide bond synthesis and the methylation of actin and myosin
Peptide Bond Formation
Covalently join the α-carboxyl group (-COOH) of each amino acid to the α-amino group (-NH2) of another by dehydration or condensation reaction
Atoms in peptide bond from a rigid, planar unit
Peptide bond has no freedom of rotation
However, the bonds involving the α-carbon can rotate freely
• Cα-NrotatedwithangleΦ(phi)
Cα-C rotated with angle Ψ (psi)
peptide bond
-Compounds formed by the binding of two or more amino acids using peptide bonds.
Caused by the carboxylic group of The first amino acid binds to an amino group. of the second amino acid
lost 1 molecule of water
will produce a dipeptide
Chemical and physical properties of amino acids
Acid-Base and Buffer Properties of Amino Acids
The breakdown of carboxylic and amino groups makes amino acids a Zwitterion
A Zwitterion is A dipolar molecule is a neutral molecule with both positive and negative charges. in the same molecule
Amino acids is Amphoteric Compound
At physiological pH of 7.4, both carboxyl and amino groups of aminoacids are completely ionized
Isoelectric point or pI
The pH at which the total charge of the amino acids or proteins is zero (net charge=0)
Solubility and buffering capacity will be minimum at
iso-electric pH
Water solubility Amino acids are white crystalline solids. It is soluble in water and soluble in polar molecules. The melting point of amino acids is relatively high compared to other organic compounds since the intermolecular forces are hydrogen bonds.
Optical Activity
Amino acids having an asymmetric carbon atom exhibit optical activity: D and L isomers
The L-amino acids occur in nature Natural amino acids
General Reactions of Amino Acids
Due to Carboxyl Group : Decarboxylation, Amide formation
Reactions Due to Amino Group :
Transamination, Oxidative
deamination, Formation of carbamino compound
Reactions Due to Side Chains: Transmethylation, Ester formation by the OH group, Reaction of the amide group, Reactions of SH group
-Protein classification
Classification by shape
1.1 Proteins that are long or interwoven into a fiber (fibrous protein) are often
Tough, soluble protein
1.2 Proteins that are globular or oval (globular protein) are proteins that are water soluble.
Functions such as enzymes, hormones, various types of immunoglobulins, hemoglobin transports 0, in the blood, and alumin transports fatty acids.
2.Classification by chemical composition
2.1 Simple proteins are proteins that are made up of pure amino acids without any other substances.
like albumin, keratin
2.2 Complex or conjugated protein consists of simple proteins and compounds.
other than protein (prosthetic group) is also included, called holoprotein, but if prosthetic is deficient
Classification by nutritional value
3.1 Complete proteins are proteins of complete quality. because it contains essential amino acids
All kinds, including animal protein (except gelatin) and soybeans
3.2 Incomplete proteins are proteins of incomplete quality. because there are amino acids
Not all types are necessary. These include general plant proteins, except soybeans.
Classification by functions in the body
4.1 is an enzyme that acts to catalyze various reactions in the body
4.2 is the structure of cells and tissues cause strength
4.3 is a protein involved in movement
4.4 is a protein that acts as a defense against damage that may occur to the cells of the body
4.5 is a hormone that controls the functions of the body to be normal
4.6 is a protein that serves to transport various substances in the body, such as hemoglobin, serves to transport oxygen from the lungs to the tissues
4.7 It is a storage protein such as ferritin.
Classification according to the characteristics of the protein diet
Proteins can be divided into two groups according to their components (NRC, 2001):
5.1 True protein is obtained by binding by peptide bonds of amino acids.
5.2 There are several types of non-protein nitrogen (NPN): urea, in trates, free amino acids.
Classification by ruminant nutrition
Proteins may be classified according to their ability to digest in the rumen of ruminants.
6.1 ruminal degradable protein (RDP) is a type of protein that is completely broken down in the rumen upon intake by an animal.
6.2 ruminal undegradable protein (UDP)
-Biological function and the importance of proteins
It is part of the body such as blood, flesh, fur, horns, hooves and other organs.
Serves as a transport (transport protein) is a protein that serves to transport oxygen gas.
and carbon dioxide, such as hemoglobin in red blood cells
It is responsible for creating new cells to replace worn out cells within the animal body.
Acts as an enzyme (enzyme) is a protein that acts in various reactions in
body, such as the process of breathing protein synthesis digestive process
It is a component of hormones and gastric juice. which is the controller of the work
various glands and normal digestion of food within the animal's body
Help the growth of baby animals in the womb. and growing animals
It helps to produce various products such as milk, egg and meat feeding.
protective proteins (protective proteins), such as the immune system for the body
Aids in the reproduction of animals because sperm and ovum can be created, it must have protein.
Acts as a storage protein
Acts on movement (Contractile protein) is the protein that is in muscle cells, namely myosin and actin.
