Biomolecules - Proteins

• Proteins - composed of one or more amino acids determined by the base sequence of nucleotides in the DNA coding; consists of carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur
• Amino Acid - smallest unit that makes up proteins
• Essential proteins - valine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, histidine (for infants)
• Conditional proteins - arginine, glutamine, tyrosine, cysteine, glycine, proline, serine, ornithine
• Non-essential proteins - alanine, asparagine, aspartate
• Antibodies - specialized proteins involved in defending the body from antigens (foreign invaders) and can travel through the bloodstream
• Contractile proteins - responsible for movement
• Hormonal proteins - messenger proteins which help coordinate certain bodily activities
• Storage proteins - stores amino acids
• Structural proteins - fibrous and stingy, provide support for cells
• Transport proteins are carrier proteins that facilitate the movement of molecules across a cell membrane
• Fibrous proteins are made up of long strings of individual fibers that bundle together to form a more solid wall of protein
• Globular protein - more soluble and have several functions including transporting, catalyzing and regulating
• Membrane protein - relays signals within cells allowing cells to interact the cell membranes and transports molecules
• Primary structure refers to the sequence of amino acids in a polypeptide chain.
• Secondary structure is formed by hydrogen bonds between different parts of the same polypeptide chain.
• Tertiary protein structure - attraction is present between alpha helices and pleaded sheet
• Quaternary protein structure - more than one amino acid chain