functions

• • enzymes – biological catalysts that control all biochemical reactions for cellular metabolism like cellular respiration, digestion e.g. amylase, and DNA replication e.g. DNA polymerase  
• • antibodies for immunity – produced by B cells that protect against pathogens
• • hormones – produced by endocrine glands that communicate messages and trigger responses in target cells, e.g. insulin  
• • structural proteins – builds tissues providing structural support in cells and organs, e.g. collagen, keratin  
• • transport proteins – carrier molecules that transport substances within or between cells like membrane channel proteins e.g. ion channels, sodium-potassium pump, and haemoglobin a red blood cell protein that binds to oxygen-carrying it to cells
• • motor or contractile proteins for movement – such as those responsible for muscle contraction to allow movement e.g. actin, myosin, and responsible for moving chromosomes during mitosis and meiosis e.g. spindle fibres are long microtubule protein fibres that extend from centrioles