proteins

• proteins are denatured by acid in the stomach, that breaks weak bonds of the tertiary and secondary structures, meaning enzymes can attack covalent bonds of primary structure
• structure and movement proteins: collagen, elastin, keratin, actin, myosin and cytoskeleton
• catalystic and immunity proteins: enzymes, hormones, neurotransmitters, antibodies
• transport proteins: haemoglobin, transferrin, retinol binding protein, albumin
• haemoglobin is a quaternary structure that transports oxygen
• transferrin transports iron
• retinol-binding protein transports hydrophobic lipids
• albumin maintains blood pressure and fluid balance in capillaries
• hydrostatic pressure forces fluid out of the capillaries into the interstitial space
• if a protein deficiency exists, there are fewer blood proteins, water can remain in the interstitial space, causing oedema
• amino and carboxyl groups can release or gain electrons to minimise changes in pH
• amino acids cant be stored, so excess is deaminated in the liver
• 200g of protein per day is degraded and synthesised
• skin cells are replaced every 30-45 days
• RBC have a lifespan of 120 days
• new proteins can be synthesised from the bodies amino acid pool
• cytocrome P450 (enzyme) is in the liver and degrades toxins