BIOL 1101: Unit 2 Open-Ended

Key Components of the Endomembrane System

nuclear envelope, ER, golgi, lysosomes, vesicles, plasma membrane

Which parts of a cell have a double membrane?

Nuclear envelope of nucleus, mitochondria, and chloroplasts

Golgi Apparatus structure

has a cis face (receiving end, near ER) and a trans face (shipping side, near plasma membrane)

What are the 3 methods of endocytosis?

Phagocytosis, pinocytosis, and receptor-mediated endocytosis

What are the 2 methods of exocytosis?

Constitutive secretion, regulated secretion

Example of Real-World Application of Receptor-Mediated Endocytosis

SARS-CoV-2 enters human cells by hijacking the receptor-mediated endocytosis pathway to let them in

Example of Real-World Application of Regulated Exocytosis

Neurotransmitter release, followed by reuptake via active transport

Example of Real-World Application of Receptor-mediated Endocytosis

In a healthy cell, this is highly efficient

LDL particles carry cholesterol throughout the blood, and the LDL particle has a protein on its surface that the cell membrane can detect via LDL receptors, and once the receptor binds, this triggers the formation of a clathrin coated vesicle that pulls the cholesterol into the cell to be used or processed

However, if you have FH, this specific pathway is blocked because of genetic mutations like defective receptors where the cell doesn’t produce enough LDL receptors, or the receptors are defective, so they cannot bind, so bloodstream has high cholesterol

How do organelles and vesicles travel throughout a cell?

Not random, pulled along the cytoskeleton by motor proteins fueled by ATP

How is ABO blood type determined?

Specific glycosylation patterns (carb chains) on the surface of red blood cells