Exam 1: Cell Compartments and Cellular Macromolecules Flashcards
How many membranes does the nuclear envelope have?
Two
What is the nuclear envelope continuous with?
The ER
What is the inside of the nuclear envelope linked to?
Fibrous proteins
What is the lattice-like sheet called in the nuclear envelope?
Nuclear lamina
What are the three roles of the nuclear lamina?
- Stiffen the membrane structure
- Maintain shape
- Provide attachment points for each chromosome
What functions as doors into and out of the nucleus?
Nuclear pores
What gives molecules entry into the nucleus? Is the process energy demanding?
Nuclear localization signal; yes
What are the 3 steps of protein production?
- Synthesis of mRNA from DNA occurs in the nucleus
- mRNA moves to cytoplasm via nuclear pores
- Protein synthesized by ribosome from mRNA code
i.e. Central dogma (DNA -> RNA -> Protein)
What are the 5 steps of the secretory pathway? (protein transport in endomembrane system)
- Ribosome deposits protein in ER
- Protein exits the ER (via ER membrane vesicle)
- Protein enters Golgi for processing
- Protein exits Golgi (via Golgi trans vesicle)
- Protein exits cell
Which face of the Golgi does the protein enter at? Exit?
Cis. Trans.
What is the role of the rough ER?
Protein production
What is the role of the smooth ER?
Lipid production and calcium storage
How are proteins shipped from the golgi?
They have a molecular tag that places it in a type of transport vesicle
What is the 5 step process for how products are shipped from the golgi?
- Proteins are tagged
- Proteins are sorted
- Vesicles bud
- Proteins interact with receptors
- Delivery
What are the two functions of the lysosome?
Digestion and waste processing