Proteins and amino Proteins and amino acidsacids

Protein FactsProtein Facts

Proteins: Polymers of Amino AcidsProteins: Polymers of Amino AcidsProteinsProteins are polymers of are polymers of amino amino acidsacids. They are molecules with . They are molecules with diverse structures and functions.diverse structures and functions.Each different type of protein has Each different type of protein has a characteristic amino acid a characteristic amino acid composition and order.composition and order.Proteins range in size from a few Proteins range in size from a few amino acids to thousands of them. amino acids to thousands of them. Folding is crucial to the function of Folding is crucial to the function of a protein and is influenced largely a protein and is influenced largely by the sequence of amino acids.by the sequence of amino acids.

Proteins are polymersProteins are polymers

ProteinsProteins are polymers of are polymers of amino acidsamino acids. They are . They are molecules with diverse molecules with diverse structures and functions.structures and functions.

Polymers are made up of Polymers are made up of units called monomersunits called monomers

The monomers in proteins The monomers in proteins are the 20 amino acidsare the 20 amino acids

Proteins: Polymers of Proteins: Polymers of Amino AcidsAmino Acids

Each different type of protein Each different type of protein has a characteristic amino has a characteristic amino acid composition and order.acid composition and order.Proteins range in size from a Proteins range in size from a few amino acids to thousands few amino acids to thousands of them. of them. Folding is crucial to the Folding is crucial to the function of a protein and is function of a protein and is influenced largely by the influenced largely by the sequence of amino acids.sequence of amino acids.

Polar side chainsPolar side chains

Non Polar Hydrophobic Non Polar Hydrophobic side chainsside chains

Electrical charged Electrical charged hydrophilichydrophilic

Functions of proteinsFunctions of proteins

Hormones – Growth hormoneHormones – Growth hormoneReceptors – to Receive Receptors – to Receive information so that cell can information so that cell can communicate with other cellscommunicate with other cellsNeurotransmitters – messenger Neurotransmitters – messenger molecules – to send information molecules – to send information between neuronsbetween neuronsCytoskeleton – actin, myosin, and Cytoskeleton – actin, myosin, and collagen – the structure of collagen – the structure of connective tissue and musclesconnective tissue and musclesAntibodies – Immunoglobulins to Antibodies – Immunoglobulins to fight diseasefight disease

Function of Proteins - Function of Proteins - continuedcontinued

Enzymes – Biological catalystsEnzymes – Biological catalystsTransport of small molecules – Transport of small molecules – Albumin and haptoglobinAlbumin and haptoglobinTransport of oxygen – Transport of oxygen – hemoglobin and myoglobinhemoglobin and myoglobinMembrane proteins – to assist in Membrane proteins – to assist in supportsupportChannels in membranes – to Channels in membranes – to allow the passage of molecules or allow the passage of molecules or ionsionsElectron carriers in electron Electron carriers in electron transport in the production of ATPtransport in the production of ATP

Functions( continued)iFunctions( continued)i

Clotting proteinsClotting proteins

Immune proteins to fight Immune proteins to fight infectious agentsinfectious agents

Histones – DNA binding proteinsHistones – DNA binding proteins

Toxins to repel or kill other Toxins to repel or kill other organismsorganisms

Bacteriocins – molecules Bacteriocins – molecules produced by bacteria against produced by bacteria against bacteriabacteria

Biochemical ReactionsBiochemical Reactions

Polymerization reaction- Polymerization reaction- condensation and dehydration condensation and dehydration synthesis – involves the loss of synthesis – involves the loss of water between two amino acids and water between two amino acids and the formation of a peptide bond the formation of a peptide bond ( OH is lost from the carboxyl group ( OH is lost from the carboxyl group and H is lost from the hydroxyl) and H is lost from the hydroxyl) requires energyrequires energyHydrolysis – the addition of water Hydrolysis – the addition of water causes the peptide bond to break causes the peptide bond to break and the amino acids to and the amino acids to separate( releases energy)separate( releases energy)

PolymerizationPolymerization

HydrolysisHydrolysis

Four levels of Protein Four levels of Protein StructureStructure

There are four levels of protein There are four levels of protein structure: primary, secondary, structure: primary, secondary, tertiary, and quaternary. tertiary, and quaternary. The precise sequence of amino The precise sequence of amino acids is called its acids is called its primary primary structurestructure. . The peptide backbone consists of The peptide backbone consists of repeating units of atoms: N—C—repeating units of atoms: N—C—C—N—C—C.C—N—C—C.Enormous numbers of different Enormous numbers of different proteins are possible.proteins are possible.