Lecture 8: How does a cell regulate its shape Flashcards
What does the Endomembrane System consist of:
Nuclear envelope, Golgi Apparatus, Endoplasmic reticulum, lysosomes, vesicles and the plasma membrane
What does the Endomembrane System do?
Regulates protein traffic & performs metabolic(protein synthesis) functions in the cell
Smooth ER function:
Synthesis of proteins, metabolism of carbohydrates, detoxification of drugs & poisons and storage of Ca+ ions
Rough ER structure:
Studded with ribosomes - has a rough appearance
Rough ER function:
Synthesis of secretory and proteins from bound ribosomes. Wraps proteins in membranes of vesicles so they can be transported out of the cell.
Golgi Apparatus structure:
Stacks of flattened membranous sacs/flattened plates. Has polarity, cis and trans face. Vesicles from ER arrive at cis face and leave at the trans face
Golgi Apparatus function: Glycosylation of proteins
Addition or modification of protein
Golgi Apparatus function: Sorting & directing proteins
Adds molecular markers to direct proteins to the correct vesicles.
Adds molecular tags to direct vesicle to the correct target compartment.
Bulk transport across the plasma membrane occurs by:
Endocytosis & Exocytosis
What is Endocytosis? (form of active transport)
Substances brought into cell by plasma membrane - substances are trapped in a section of plasma membrane that pinches inward to from a vesicle- cell engulfs molecules by extending its membrane around.
What is Phagocytosis? (form of endocytosis)
Uptake of food particles “cell eating”
What is Pinocytosis? (form of endocytosis)
Uptake of non-selective solutes “cell drinking”
What is Exocytosis?
- movement of substance out of cell by fusing a secretory vesicle with the plasma membrane which releases its contents.
What is non-secretory exocytosis?
Delivers material to the cell surface
What is the constitutive pathway?
Its ongoing and continuous exocytosis e.g extracellular matrix
