The Endomembrane SystemA Tour of the Protein Synthesis Pathway
Essential Question(s)
1. Why do eukaryotic cells maintain internal membranes that partition cells into specialized regions?
Prokaryotes vs. Eukaryotes
Prokaryote Eukaryote
Compartmentalization
Cellular Work
Building Proteins
Cells
Proteins
DNA
Organism
Protein Synthesis Overview
Ribosome rER Golgi Vesicles
The Protein Assembly Line
The Endomembrane System
Nucleus
Endomembrane System
Nucleus
Nucleus
Nucleolus
Ribosomes
Types of Ribosomes
Bound Ribosomes Free Ribosomes
Endoplasmic Reticulum
Rough ER
Smooth ER
Synthesizing Secreted Proteins
cytoplasm
cisternalspace
mRNA
ribosomemembrane ofendoplasmic reticulum
polypeptide
signalsequence
ribosome
Golgi Apparatus
Vesicular Transport
vesicleBUDDINGfrom roughER
protein
ribosome
migratingtransportvesicle
FUSIONof vesiclewith Golgiapparatus
Putting it All Together
proteins
transportvesicle
Golgiapparatus
vesicle
smooth ER
rough ERnuclear pore
nucleus
ribosome
cellmembrane protein secreted
cytoplasm
Putting it All Together
Enduring Understandings1. Archaea and bacteria generally lack internal membranes and
organelles and have a cell wall.
2. Membranes and membrane-bound organelles in eukaryotic cells localize – compartmentalize – intracellular metabolic processes and specific enzymatic reactions.
3. Internal membranes facilitate cellular processes by minimizing competing interactions and by increasing surface area where reactions occur.
4. Ribosomes are small , universal structures comprised of two interacting parts; ribosomal RNA and protein. In a sequential manner, these cellular components interact to become the site of protein synthesis where the translation of genetic instructions yields specific polypeptides.
Enduring Understandings5. Rough endoplasmic reticulum – rER – functions to
compartmentalize the cell, serves as mechanical support, provides site-specific protein synthesis with membrane-bound ribosomes and plays a role in intracellular transport.
6. The smooth endoplasmic reticulum – sER – synthesizes lipids.
7. The Golgi complex is a membrane-bound structure that consists of a series of flattened membrane sacs, called cisternae.
8. Functions of the Golgi include synthesis and packaging of materials – small molecules – for transport in vesicles and production of lysosomes
Small Group CFU 1• Take 2 minutes
• Spend the next 2 minutes with your partner clarify your understanding of the topic by asking and answering your questions with your partner. Be sure to identify content that you missed or were confused about, and clarify these points.
• Annotate your notes using symbols to identify the main ideas, underlining or highlighting key terms, or adding supporting details, examples or explanations to figures.
• After three minutes have expired, work with your partner to answer the multiple choice notes-check questions. You may discuss the solutions with only your partner, quietly.
• Answer each of these questions using your notes, and underline the statement or phrase that provides the answer. This will denote the most importance information for your review later on.
• Record any clarifying questions at the bottom of your page
Protein Synthesis Overview
Synthesizing Secreted Proteins
cytoplasm
cisternalspace
mRNA
ribosomemembrane ofendoplasmic reticulum
polypeptide
signalsequence
ribosome
Putting it All Together
proteins
transportvesicle
Golgiapparatus
vesicle
smooth ER
rough ERnuclear pore
nucleus
ribosome
cellmembrane protein secreted
cytoplasm