Organelles involved in synthesis and secretion of proteins Examples of proteins: hormones eg insulin enzymes eg amylase

Transcription – mRNA copies DNA code mRNA takes code through nuclear pore to ribosome Translation – on ribosomes - amino acids are assembled in the correct order using the code to make a protein

Division of labour – synthesis of a protein

The Inner Life of the Cell

protein

The rough endoplasmic reticulum transports the proteins through the cytoplasm and packages them in vesicles which pass to the Golgi apparatus

The Golgi apparatus receives vesicles containing protein from ER, modifies them (eg adds a carbohydrate group) and packages them into more vesicles to send to the cell surface membrane Virtual Cell movie Golgi apparatus Another animation

Fibroblasts showing actin & Golgi apparatus Cultured rat embryo fibroblasts scraped to simulate wounding. After scraping the Golgi reorient to the side of the cell nearest the wound. Filamentous actin is stained in red and the Golgi complex in green

Constitutive secretion Exocytosis – the vesicles containing finished protein fuse with the cell surface membrane and release their contents to the outside (secretion) Animation Constitutive secretion Regulated secretion

Put these in order! secretory vesicle Nucleus Cell surface membrane Ribosome (could be on ER) Golgi Nucleus Ribosome (could be on ER) Golgi secretory vesicle Cell surface membrane