Endocrine System

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Endomembrane System

houses the organelles Endoplasmic reticulum, Golgi complex, endosome, lysosomes, vacuoles. 

Autoradiography

Is used to detect and track raidoactive substances with cells, tissues, or molecular gels

Nuclear Magnetic Resonance

is used to study biomolecules in their native liquid state at room temperature

Pancreatic Acinar Cells

are exocrine cells in the pancreas responsible for producing digestive enzymes

James jamieson and George palade

researchers that used the pancreatic acinar cells as a model to map out the eukaryotic secretory pathway and protein synthesis.

Endoplasmic Reticulum

site for secretory protein synthesis; discovered through autoradiography

Autoradiography

used radio iosotopes of a chemical element with unstable nuclei that decay,

alpha, beta, and gamma rays

Autoradiography emitts these until stability is reached.

Nuclear spin in the NMR

provides a number and type of atoms and how they are connected

No Magnetic field

when nuclear spins are oriented randomly

With Magnetic Field

The nuclear spins become parallel to the direction of the field.

constitutive secretion

materials are transported in secretory vesicles from the ER into the extracellular space continously

Regulated secretion

Hormones, enzymes, and neurotransmitters are stored as membrane bound packages.

Endocytic Pathways

where materials move from the outside to endosomes and lysosomes.

Lysosomal enzymes

degrades the materials present in the endocytic pathway.

Smooth ER

detoxifies the liver from barbiturates and ethanol

Barbiturates

a drug that prevents convulsions and siezures

Oxygenase

an O2-transferring enzyme; converts drugs into more excreted derivatives.

Adrenal cortex

Where steroid hormones are synthesized by the Smooth ER

Cortisol

Stress hormones

Aldosterone

hormones that regulates blood pressure.

Androgen

hormones for early development

Adrenal cortex

Where cortisol, Aldosterone and Androgen synthesizes steroid hormones

Adrenaline (epinephrine)

hormones for fight or flight response

Norepinephrine

transmits nerve signals in synapses

adrenal medulla

where the hormones adrenaline and norepinephrine synthesizes steroid hormones.

benzo[a]pyrene

a detoxifying enzyme in charred meat; its converted into a carcinogen by SER

Rough ER

site for proteins synthesis; also synthesizes phospholipids and carbohydrates.

mammalian genome

Where 1/3rd of proteins is encoded

free ribosomes

non-membranous cellular structures that float unhindered in the cytosol to synthesize proteins

Small subunit

binds to large subunit and mRNA

Large subunit

binds to tRNA; amino acids and smaller sub units

Prokaryotes

occurs freely in cytoplasm

Eukaryotes

free in cytoplasm and is bound to the ER

Mammalian cells

has 10 Million cells

ER Membrane

Where translocation of secretory proteins occur.

The signal Hypothesis

Its where synthesis of secretory, lysosomal, or plant vacuolar proteins happen; synthesis of integral proteins

Gunter Blobel

won a nobel prize in medicine in 1999

D. Sabatini and B. Dobberstein

co authors of the signal hypothesis

N-terminus

directs the emerging polypeptide and ribosome to the ER

translocon

parts: SRP receptor, ribosome receptor, signal peptidase and pore protein its a multi protein channel

SRP; signal regocnition particle

It mediates the co-translational targeting of secretory, lysosomal, and integral membrane proteins to the ER

1st step of synthesis of secretory lysosomal or plant vacuolar proteins

Synthesis of secretory lysosomal or plant vacuolar proteins; recognition of signal peptide by SRP

2nd step of synthesis of secretory lysosomal or plant vacuolar proteins

Synthesis of secretory lysosomal or plant vacuolar proteins; GTP binds to SRP and SRP receptor, it pre-opens and polypeptide is inserted (Turning on)

SRP and SRP receptor

2nd step of Synthesis of secretory lysosomal proteins: Where the GTP binds into.

Polypeptide

2nd step of Synthesis of secretory lysosomal proteins; This is inserted

3rd step of synthesis of secretory lysosomal or plant vacuolar proteins

synthesis of secretory lysosomal or plant vacuolar proteins; Attachment of Ribosomes to the ER is mediated by the SRP receptor and translocon

SRP receptor and Translocon

3rd step of Synthesis of secretory lysosomal proteins; The mediator during the attachment of ribosomes to the ER membrane

4th step of synthesis of secretory lysosomal or plant vacuolar proteins

synthesis of secretory lysosomal or plant vacuolar proteins; GTP is hydrolysed, and SRP is released (Turning off)

GTP and SRP

4th step of synthesis of secretory lysosomal or plant vacuolar proteins; This is hydrolysed, and the other is released.

5th step of synthesis of secretory lysosomal or plant vacuolar proteins

Synthesis of secretory lysosomal or plant vacuolar proteins; SRP is released and the signal peptide binds to the translocon.

6th step of synthesis of secretory lysosomal or plant vacuolar proteins

Synthesis of secretory lysosomal or plant vacuolar proteins; The rest of the polypeptide translocates through the ER lumen co-translationally.

Signal Peptidase

Cleaves the signal sequence as the polypeptide elongates and translocates into the ER lumen.

Signal Peptidase

An enzyme that removes the N-Terminus of the signal sequence.

Oligosaccharyltransferase

Enzyme that adds carbohydrates

6th step of the Synthesis of integral proteins on membrane-bound organelles

given that its an integral protein; they have a hydrophobic stop transfer sequence that block further movement of the protein into the ER lumen.

Hydrophobic stop transfer

present in the 6th step of the synthesis of integral proteins on membrane-bound organelles that block further movement of the protein into the ER lumen.

7th step of the synthesis of integral proteins on membrane-bound organelles

the lateral gate of the translocon opens and the newly synthesized integral proteins integrate into the lipid bilayer of the ER membrane

Misfolded Proteins

These are transported into the cytosol by reverse translocation.

Proteasome

a protein degrading machine

Unfolded protein response

a plan of action when misfolded proteins accumulate because of potential lethality.

Protein sensors

This monitors the amount of misfolded and unfolded proteins

BiP (ER Lumen)

A chaperone molecule to keep protein sensors active when misfolded proteins are high; activates the protein sensors to signal the nucleus and cytosol

Apoptosis

Programmed cell death; a necessary mean when cells are compromised.

Nucleus and Cytosol

genes present here encode chaperone molecules and proteins to destroy misfolded proteins

Chaperone molecules and proteins

deployed by the Nucleus and Cytosol genes to destroy misfolded proteins

Camillo Golgi

discovered the Golgi Apparatus

Nobel prize; 1906

What and When; won by Camillo Golgi

Golgi Apparatus

Next to the smooth ER; they are complex; storage and transport

Cis

Entry face closest to the ER

Cis Golgi Network

Sorts out proteins to be shipped back to the ER and those to proceed to the golgi complex

Trans

Exit Face

Trans Golgi Network

sorts out proteins into vesicles heading to the plasma membrane and intracellular organelles.

Cisternal maturation model

This is where each cisterna matures into the next cisterna along the stack.

Cisterna

flattened membrane

Vesicular Transport Model

secretory, lysosomal, and membrane protein shuttle through CGN to TGN in vesicles that bud from one compartment and fuse with a neighboring compartment

COPII coated vesicles, COPI coated vesicles, and Clathrin

The three best studied coated vesicles in protein trafficking

COPII coated vesicles

moves materials from ER to ERGIC

Anterograde

Forward movement that delivers to the entry phase

COPI coated vesicles

moves materials backward from ERGIC and golgi complex to ER, from TGN to CGN

Retrograde

Backwards movement

Clathrin coated vesicles

membrane bound carriers that transport proteins and lipids from TGN to lysosomes and endosomes

Clathrin

a protein that forms a structural scaffold

Inner shell

with proteins adaptros facing the cytosol.