New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

chapter 15 notes

by: Brenna Eisenberg

chapter 15 notes 327

Marketplace > Syracuse University > Biology > 327 > chapter 15 notes
Brenna Eisenberg
GPA 3.535

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

Notes from chapter 15 of the textbook. Intracellular compartments and protein transport
Cell Biology
Class Notes
Science, Biology, cellular biology, cell communication, endomembrane system, endocytosis, textbook notes, Proteins, vesicles, transport, nucleus, cells
25 ?




Popular in Cell Biology

Popular in Biology

This 2 page Class Notes was uploaded by Brenna Eisenberg on Wednesday October 5, 2016. The Class Notes belongs to 327 at Syracuse University taught by erdman in Fall 2016. Since its upload, it has received 3 views. For similar materials see Cell Biology in Biology at Syracuse University.


Reviews for chapter 15 notes


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 10/05/16
Intracellular compartments and protein transport Chapter 15 Wednesday, October 5, 2019:52 PM • Membrane enclosed organelles ○ Nucleus- surrounded by nuclear envelope that is perforated by the nuclear pores.  Outer nuclear membrane is continuouswith the membrane of the endoplasmic reticulum ○ Endoplasmic reticulum (ER)- site of synthesis of new membranes  Rough ER has ribosomes attached to the outside. The ribosomes synthesize proteins that are sent into the ER  Smooth ER- synthesizes steroid hormones, sequesterscalcium from cytosol ○ Golgi apparatus- modifies proteins and lipids from ER ○ Lysosomes- degrade particles and worn out organelles  Particles pass through endosomes that organize the ingested molecules and cycle some back to the plasma membrane ○ Peroxisomes- carry out oxidative reactions, break down lipids and toxic molecules ○ Mitochondria-site of oxidative phosphorylation ○ Chloroplasts- site of photosynthesis • Organelles surrounded by cytosol that is enclosed by the plasma membrane • Organelles held in place by attachment to cytoskeleton by microtubules, moved by cytoskeletal filaments • Endomembranesystem- ER, golgi, peroxisomes, lysosomes, endosomes. ○ Communicate extensively with small vesicles that bud off • Before cell division, the proteins that are being produced must be delivered to the correct organelle • Mechanisms of protein transport: Proteins going from cytosol to nucleus go through the nuclear pores that are selective gates ○ Proteins going from cytosol to ER, mitochondria or chloroplasts get across the membrane by membrane translocators. Protein usually has to unfold to get through ○ Proteins moving from 1 compartment to another are carried in transport vesicles that pinch off from 1 compartment and fuse to another • Signaling sequence: sorting signal sends the protein to the correct organelle. Without the signal, they remain in the cytosol. Usually removed after it has been sorted. • Inner nuclear membrane- contains proteins that are binding sites for chromosomes or are an anchor for the nuclear lamina • Nuclear lamina- meshwork of protein filaments. Lines the inner part of the membrane and is structural support for the nuclear envelope. • Outer nuclear membrane- similar to the membrane of the ER that it is continuous with • Nuclear pore- composed of ~30 different proteins. Has a tangled meshwork that prevents large molecules from passing. Small molecules that are water soluble can pass freely. Large molecules need the correct sorting signal to get in ○ Nuclear localization signal is recognized by nuclear import receptors that interact with the fibrils of the pore. They then open a local passageway. ○ Import of nuclear proteins requires energy from GTP hydrolysis • Proteins must unfold to enter mitochondria and chloroplasts ○ Chloroplasts have 3rd membrane system ○ Chaperone proteins pull protein across and help fold when it is inside • Peroxisomes have enzymes that produce H2O2. Also synthesize some phospholipids ○ Their proteins are mainly imported from the cytosol ○ Membrane has a protein translocator ○ Proteins do not need to unfold • Proteins travel from cytosol to ER, then to other destinations • Once inside the ER, they then travel via vesicles ○ Cytosol to ER: water soluble proteins translocated across ER and into the lumen, as well as prospective transmembrane proteins that are partially translocated across membrane and are embedded in it.  Water soluble proteinsare then destined for secretion at the cell surface or for the lumen of an organelle ○ Most of the proteins entering the ER are not completely synthesized and are still being synthesized by the ribosome of the rough ER. ○ Membrane bound ribosomes make proteins that are to be transported to ER ○ Free ribosomes make all other proteins encoded by DNA • Signal recognition particles (SRP) bind to ribosome and ER signal sequence • SRP receptors recognize the SRP • Vesicular transport-allows communication between the inside of the cell and its surroundings ○ Secretory pathway- outward. Starts with synthesis of proteins ○ Endocytic pathway- responsible for ingestion and degradation of extracellular molecules ○ Vesicles must fuse to the appropriatemembrane ○ Coated vesicles- bud from membranes and have a distinctive protein coat on the cytosolic surface. They then shed the coat and interact with the membrane it will fuse with  Ex- clathrin coated vesicles. ○ Adaptins- secure clathrin coat to the vesicle membrane and also select the molecules which are to be transported. These molecules will carry transport signals. Adaptins trap the cargo receptors that bind to the cargo molecules • Vesicle docking: Chapter 15 Page 1 • Vesicle docking: ○ Identificationof the vesicles is done by Rab proteins that are on the surface. There are tethering proteins on the surface of the target membrane that recognize the Rab proteins. ○ SNAREs on the vesicle interact with complimentary SNAREs on the target membrane, which docks the vesicle in place. Also have a role in membrane fusion-- catalyze the fusion process • Exocytosis: ER (made and modified→ golgi (modified and sort→d)plasma membrane • Disulfide bonds are catalyzed in the ER. Glycosylation of proteins also occurs here. • Some proteins are kept in the ER by an ER retention signal • Unfolded protein response- occurs when there is a large buildup of misfolded proteins. The cell will produce more ER • Golgis have two faces: entry/cis face, and exit/trans face (points toward the plasma membrane). ○ Additional modification of oligosaccharide chains • Constitutive exocytosis pathway- vesicles bud from trans face of golgi and fuse with the membrane. Supplies plasma membrane with new lipids and proteins • Regulated exocytosis pathway- for secretory cells • Endocytosis: ○ Pinocytosis- "cellular drinking" ingestion of fluid and molecules ○ Phagocytosis- "eating" ingestion of large particles. Done mainly by phagocytic cells such as macrophages • Endosomes sort endocytosed molecules • Autophagy- degrades old parts of the cell Chapter 15 Page 2


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Kyle Maynard Purdue

"When you're taking detailed notes and trying to help everyone else out in the class, it really helps you learn and understand the I made $280 on my first study guide!"

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."


"Their 'Elite Notetakers' are making over $1,200/month in sales by creating high quality content that helps their classmates in a time of need."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.