BSCI170: How the Endomembrane System Works

10/6 notes

Order of the endomembrane system

1. Nucleus: RNA is created

2. Nuclear envelope: RNA leaves nucleus

3. Rough ER: uses RNA to synthesize and modify proteins

4. Transport vesicles: transports proteins from rough ER to golgi apparatus

5. Golgi apparatus: further modification, sorting, and packaging

6. Secretory vesicles: secretes proteins out of the cell

7. Plasma membrane: releases proteins outside of the cell through exocytosis

*vesicles are always needed for transportation; think of proteins/phospholipids as babies who can’t be trusted to go to places on their own so they needed a truste adult. that trusted adult is the vesicle

Transport vesciles - in depth

inside, polypeptide will turn into glycoprotein, and a part of the rough ER will bud off and turn into vesicle to transport the phospholipid/protein to the golgi apparatus

Golgi Apparatus: in depth

Cis face: side of golgi facing/closest to ER

• transport vesicles fuse w/ cis face bc it’s closer

Trans face: side of golgi facing away/further from ER

things will move from the cis face to trans face

Secretory vesicles

buds off from golgi apparatus and transports proteins/phospholipids from the golgi apparatus to plasma membrane by fusing with it

Plasma membrane

either secretes phospholipids/proteins or it stays inside

Lysosomes function

trashbag organelle; breaks down molecules like proteins, other oranelles, lipids, nucleic acids, etc.

• very acidic

• has digestive enzymes

What is autophagy

breakdown of damaged organelles

• lysosomes aid in this

what is phagocytosis

cells called phagocytes ingest foreign particles like bacteria, viruses, and other dead cells

• lysosomes aid in this

Mitochondria: Where is it found, function, and characteristics

Found in:

• animal cells

• plant cells

Function: generates ATP through aeriobic respiration

• breaking ATp produces energy

• waste is carbon dioxide

Characteristics:

• outer membrane: permeable to lots of molecules

• inner membrane: less permeable, has cristae (lots of folds)

• has their own DNA and ribosomes

Chloroplasts: Where it’s found, function, and characteristics

Found in:

• plant cells

Function: 

• site of photosynthesis; converts solar energy to chemical energy

Characteristics:

• has inner and outer membrane

• stroma: space inside inner membrane

• thylakoids: inner membrane structure that look like flat discs