Histo Organelles 0814

Front 1

What determines the abundance and distribution of organelles in a cell?

Back 1

the particular physiology needs of the cell, the function of the cell

Front 2

Function and parts of ribosomes?

Back 2

Synthesize proteins, small subunit binds to mRNA first, then large subunit binds

Front 3

What are the functions of organelles?

Back 3

Concentrate enzymatic rxns.
Segregate competing metabolic processes.
Segregate harmful products from the rest of the cell.

Front 4

What are the functions of these organelles?
Nucleus
Mitochondria

Back 4

segregates replication and transcription
concentrates energy-producing rxns

Front 5

What is the function of these systems?
Endocytotic sys.
Secretory sys.

Back 5

-Controls the absorption and the fate of ingested materials
-organizes the synthesis, transport and quality control of carbohydrates,proteins, nucleic acids and lipids

Front 6

Function of monitoring mechanisms?

Back 6

assure quality control of all cell products, neutralize toxic substances and recycle intracellular signals

Front 7

What is process/sequence of exocytosis?

Back 7

(primarily the production and export of proteins)
ER -> Golgi -> Secretory vesicles -> exterior of cell
* sometimes small proteins are exported directly, no vesicle necessary.

Front 8

What is process of endocytosis?

Back 8

Cell exterior > early endosome > late endosome> lysosome or golgi to ER

Some materials are recycled to the exterior of the cell or to the golgi and ER.

Front 9

What kind of proteins are synthesized for intracellular use ?

Back 9

Soluable and nuclear enzymes, proteins to replace/repair organelles, new membrane proteins.

Front 10

whats the sequence of events for synthesizing intracellular proteins?

Back 10

ER > golgi > cytosol
ER > cytosol
or made in cytosol (free polyribosomes make protein in cytosol)

Front 11

Where are proteins synthesized?

Back 11

Free ribosomes, make intracellular proteins (soluable and nuclear enzymes, replace/repair proteins, some plasmalemma proteins)
Ribosomes on RER, make secretory, lysosomal, and basic plasma membrane proteins

Front 12

Where are lipid components of new plasma membrane made?

Back 12

Golgi

Front 13

What targets proteins to their destination?

Back 13

Signal peptides

Front 14

Basophilia stain properties

Back 14

Basic (+) dyes like hematoxylin (blue) dyes basophilic (-) substances like RNA, DNA, glycosaminoglycans

Front 15

Acidophilia (eosinophilia) stain properties

Back 15

Acid (-) dyes like Eosin (orange G). Dyes + substances like cytosolic proteins, collage, hemoglobin

Front 16

What are the steps of synthesizing secretory proteins across the ER?

Back 16

. Note the “signal sequence” attached to the end of the nascent polypeptide chain.
2. This signal sequence directs the ribosome to bind the Signal Recognition Protein (SRP) and move to the ER membrane..
3. The SRP binds to the SRP receptor on the ER membrane and to GTP.
4. These events open the translocon to receive the polypeptide chain. Both the SRP and its receptor hydrolyze GTP and dissociate from the transcolon.
5. The signal sequence is cleaved off by the adjacent signal peptidase.

Front 17

Where can you find lots of Rough ER (wall to wall)?

Back 17

In cells that secrete/make lots of proteins.

Front 18

What is transcription, translation, codons, tRNA, mRNA, and rRNA?

Back 18

transcription -RNA synthesis
Translation - protein synthesis
codons - combos of three bases that code for specific amino acids
tRNA - transfer RNA, brings specific AAs to ribosome/mRNA complex to be made into protein
mRNA - messenger RNA,The template for the amino acid sequence of a unique protein; read by ribosome
rRNA - ribosomal RNA, involve with ribosome in synthesizing proteins

Front 19

where are subunits of ribosomes made?

Back 19

Nucleolus

Front 20

Where can you find polyribosomes?

Back 20

attached to ER or free in cytosol

Front 21

development of antibiotics was enabled by knowledge what type of synthesis?

Back 21

protein synthesis in prokaryotes

Front 22

what happens to a protein made in the rough ER?

Back 22

RER ribosomes sit on membrane, when make protein, enters the lumen, forms its configurations, get glycosylated, proteins may remain in lumen, or travel to Golgi and transported by vesicular transport to extracellular space or into lysosomes (hydrolases), or into plasma membranes

Front 23

What function does the signal sequence provide?

Back 23

know the exact address of proteins once compelete, where they are bound for, based on the signal peptide, which can be as short as 3 peptides or as long as 80.

Front 24

What enables self-assembly of a protein into its 3d structure?

Back 24

Signal patches

Front 25

What happens to misfolded proteins made in ER?

Back 25

Accumulate in the cytosol or the lumen of the rough ER.

Front 26

Name two diseases that involve protein misfolding in their etiology.

Back 26

Alzheimer’s Disease, get tangles and extracellular amyloid plaques, and Mad Cow disease

Front 27

What proteins may assist in the folding process of proteins?

Back 27

Chaperone proteins.

Front 28

What is rough ER, and what are its roles?

Back 28

RER is studded with ribosomes and is engaged in protein synthesis. It typically has a lamellated appearance—like stacks of pita bread.
Protein synthesis, quality assurance (using quality control mechanisms eg chaperone proteins), endolysomal system, (proteosome pathway).
The glycosylation of proteins (acts as destination signal tag).

Front 29

What is a disease is caused by problem with folding of protein, stays in ER, so ER get swollen with accumulated misfolded trypsin

Back 29

a-1 anti-trypsin deficiency disease

Front 30

What role do microtubules fill for the rough ER?

Back 30

microtubules responsible for maintaining the structure of RER, it would collapse without microtubules

Front 31

what directs completed protein in the cytosol?

Back 31

singal peptides

Front 32

what are some destinations for proteins made in the cytosol?

Back 32

nucleus, chloroplast, mitochondria (has to unfold), peroxisome, ER

Front 33

what are the important roles for smooth ER and the location where these occur?

Back 33

Glycogen metabolism (liver and muscle)
Detoxification using p540 complex (liver)
Calcium storage (skeletal and cardiac muscle)
Lipid metabolism (all cells)
Steroid metabolism (adrenal glands, ovaries, testis)

Front 34

What are the two faces of the golgi apparatus?
What is its role?

Back 34

Cis and trans
Processes and sorts secreted and membrane proteins

Front 35

Describe the Golgi Complex and its function

Back 35

Membranous cisternae with a variety of enzymes, which are involved in terminal glycosylation, phophorylation, and sulfation of proteins, proteoglycan synthesis, and sorting of all these proteins to their final destinations (eg cell memb, secretory granuals, lysosome).

Front 36

Describe sequence of passing through the golgi

Back 36

Protein-laden vesicles arrive from ER at the CIS golgi, transverse several intermediate cisternae, and then are sorted for their final destination in the Trans-golgi network/side (TGN)

Front 37

Give an example of protein sorting/targeting.

Back 37

Receptor/ligand process. Lysosomal enzymes get attached to mannose-6-phosphate tag in the golgi. A mannose-6-phosphate receptor in the TGN recognizes the tag and proteins are delivered in cathrine-coated vesicles to the late endosome/lysosomal compartment.

Front 38

What might lots of Golgi in a cell indicate about that cell?

Back 38

Secreting lots of materials, proteins.

Front 39

How are vesicles transported from the ER to the cis Golgi network?

Back 39

Microtubules with their motor proteins move along clusters of vescicles.

Front 40

What does COP stand for? What is the function of the COPI and COPII coats?

Back 40

Help direct vesicles to destinations
COP = coat protein complex, they are specific signal "address" peptides. COPI directs vesicles back to the ER from the Golgi, COPII directs them to the Golgi from the ER.

Front 41

Role and characteristics of Mitochondria

Back 41

Produce ATP via Kreb's cycle, Electron Transport Chain and ATP synthase. Has 4 domains created by inner and outer membranes. Inner membrane, surrounding the matrix, has cristae to increase surface area. Mitochondria have own DNA, which codes from some of its own rRNA, mRNA, and tRNA.
Can divide independently of the host cell.

Front 42

Amount of ATP created by one mole of glucose?

Back 42

36-38 moles of ATP

Front 43

What do plasma cells do?

Back 43

Make antibody proteins at about 2000 per second, live about 4-5 days, have wall to wall ER.

Front 44

Compare constitutive and regulated secretion

Back 44

constitutive is unregulated and occurs all the time. In Regulated secretion the secretory vesicle waits in cytoplasm until signal (eg hormone, NT) is received that contents are needed.

Front 45

Golgi functions

Back 45

-Limited glycosylation (&/or modification) of proteins
-Synthesis and modification of polysaccharides
-Sulfation of proteins, oligosaccharides
-Phosphorylation of lysosomal enzymes
VERY IMP : Regulation of protein traffic: tagging, targeting and sorting

Front 46

Smooth ER functions

Back 46

Synthesis of:
-membrane lipids in essentially all cells (eg phospholipids, cholesterol, glycolipids)
-synthesis of steroid hormones (ovary, testis, adrenal gland)
-contains enzymes for gluconeogenesis and glycolysis (liver, skeletal muscle)
-Drug metabolism and detoxification (cytochrome p540 enzymes)
-Sequestration and release of calcium (cardiac and skeletal muscles)

Front 47

Give overview of oxidative phosphorylation

Back 47

Using fatty acids (derived from lipid stores) and pyruvate (derived from the breakdown of sugars through glycolysis) as starting material, acetyl-CoA is produced and fed into the Kreb's cycle, oxidized to yield high energy electrons which are then passed down the electron transport chain located on the inner mitochondrial membrane. The energy derived from this reaction is used to pump protons across the inner membrane, creating a gradient which is relieved by the movement of protons through the ATP synthase complex of the inner membrane leading to the production of ATP.

Front 48

Characteristics of Peroxisomes

Back 48

Found in all eukaryotic cells
most abundant in liver and kidney, membrane-bound, non-descript bodies, 0.2-1.0mm diameter, contain ~ 50 enyzmes

Front 49

Roles of Peroxisomes

Back 49

fatty acid oxidation (incl. long chain [>20 CH2] fatty acids, e.g. beta oxidation)
detoxification of ethanols, phenol, formaldehyde
lipid biosynthesis, e.g. plasmalogens (myelin phospholipid)
break down free radicals ?

Front 50

Role of Proteosomes

Back 50

Proteosomes degrade endogenous proteins (those synthesized within the cell) and smaller signal peptides, e.g.., transcription factors, cell cycle cyclins, and importantly, misfolded proteins. Proteosomes are the obsolete message shredder of the cell.

Front 51

What is the most common phospholipid in the membrane?

Back 51

Phosphatidylcholine