2. The structure and functions of Endoplasmic Reticulum(Er) (a)Rough endoplasmic reticulum 0.5 um(b)Smooth endoplasmic reticulum 0.5m Figure 12-2 Rough and Smooth Endoplasmic Reticulum. studded with ribosomes (TEM). (b)Electron micrograph of smooth (a) Electron micrograph of endoplasmic reticulum. The rough ER is endoplasmic reticulum (TEM) RER has ribosomes on the cytosolic side of continuous, flattened sacs(cisternae) SER is an interconnecting network of tubular membrane elements Rough endoplasmic reticulum and Smooth endoplasmic reticulum
2. The structure and functions of Endoplasmic Reticulum(ER) Rough endoplasmic reticulum and Smooth endoplasmic reticulum RER has ribosomes on the cytosolic side of continuous, flattened sacs(cisternae); SER is an interconnecting network of tubular membrane elements
A. Functions of the rER (a)initiation df tranlation in the cytosol Camino ano) o Proteins synthesized (e) Ribosomes rema n tree on ribosomes of rEr include secretory proteins 0@ integral membrane n croat Or e mported nlo an oreas e proteins soluble proteins of Plasma organelles w思 ooPlast COTRANSLATIONAL IMPORT ento erhenhostinaion POSTTRANSLATIONAL MPCR Figure 21-14 Intracellular Sorting df Proteins. (a)Synthesaolal eher amars n re EF er is transported wa war ous vessles call ribosomal s units assooate with each ather and with th 5'erdot an mHN miec e, foming a functional ribosome hu stars maung th papre When the g t emers one of twa altemate pathways [bl If dastned tor ay of the end the pdlypeptce s assaciated wih the ER membrane: menba into we lumn osteal space时 he ER as shes语me crenelle by posdrans at cr al mpe Polypeptide bhe This pocEss cotrarstoal immort The competed po'ytrtidtm tcus occus va te cr pores, tsing a mechanisn d ert fromer han
A. Functions of the rER ❖ Proteins synthesized on ribosomes of rER include: ➢ secretory proteins, ➢ integral membrane proteins, ➢ soluble proteins of organelles
Synthesis of membrane lipids Most membrane lipids are synthesized enterly within the ER There are two exceptions (1) sphingomyelin and glycolipids, (begins in ER; completed in Golgi) (2)some of the unique lipids of the Mit and ChI membranes(themself) The membranes of different Organelles have markedly different lipids composition Transport by budding:ER→GC、Ly、PM Transport by phospholipid exchange proteins(PEP): ER-other organelles (including mit and ChI
❖Synthesis of membrane lipids ➢ Most membrane lipids are synthesized enterly within the ER. ➢ There are two exceptions: (1) sphingomyelin and glycolipids, (begins in ER; completed in Golgi); (2) some of the unique lipids of the Mit and Chl membranes (themself). ➢ The membranes of different 0rganelles have markedly different lipids composition. ▪ Transport by budding：ER→GC、Ly、PM ▪ Transport by phospholipid exchange proteins(PEP)：ER→other organelles （including Mit and Chl）
B. Functions of the ser Synthesis of steroids in endocrine cells Detoxification of organic compounds in liver cells System of oxygenases---cytochrome p450 family release of glucose 6-phosphate in liver cells . Sequestration of Ca2+ Ca2+-ATPase
B. Functions of the sER ❖Synthesis of steroids in endocrine cells. ❖Detoxification of organic compounds in liver cells. System of oxygenases---cytochrome p450 family ❖Release of glucose 6-phosphate in liver cells. ❖Sequestration of Ca2+ . Ca2+ -ATPase
3. The structure and functions of Golgi complex A. The polarity of Golgi complex cis FACE Golgi vesicle network ICGN) cis cisterna medial cisterna trans cisterna trans secretory vesicle trans FACE nuclear CIS Golgi (B) C
3. The structure and functions of Golgi complex A.The polarity of Golgi complex