globular proteins

• In a globular protein, the hydrophilic R groups on the amino acids tend to be pushed to the outside of the molecule. This is caused by the hydrophobic and hydrophilic interactions in the protein's tertiary structure. This makes globular proteins soluble, so they're easily transported in fluids.
• globular proteins 


  round and compact
• Haemoglobin is a globular protein that carries oxygen around the body in red blood cells. It's known as a conjugated protein - this means it's a protein with a non-protein group attached. The non-protein part is called a prosthetic group. Each of the four polypeptide chains in haemoglobin has a prosthetic group called haem. A haem group contains iron, which oxygen binds to.
• Insulin is a hormone secreted by the pancreas. It helps to regulate the blood glucose level. Its solubility is important - it means it can be transported in the blood to the tissues where it acts. An insulin molecule consists of two polypeptide chains, which are held together by disulfide bonds. When they're in the pancreas, six of these molecules bind together to form a large, globular structure
• Amylase is an enzyme that catalyses the breakdown of starch in the digestive system. It is made of a single chain of amino acids. Its secondary structure contains both alpha-helix and beta-pleated sheet sections. Most enzymes are globular proteins.