Lecture 7 - Cytoplasmic Organelles Flashcards
O-linked glycosylation occurs in which of the following locations?
A. Mitochondrial matrix
B. Rough ER
C. Golgi medial stack
D. Lysosome
C. Golgi medial stack
Vesicles transported from the ER to the TGN are coated with which of the following coatings?
A. Clathrin
B. COPII
C. COPI
D. Dark chocolate
B. COPII
Cardiolipin is associated with which of the following membranes?
A. TGN
B. Outer mitochondrial membrane
C. Inner mitochondrial membrane
D. Smooth ER
C. Inner mitochondrial membrane
Which of the electron transport chain complexes receives protons and electrons from succinate?
A. Complex I
B. Complex II
C. Complex III
D. Complex IV
B. Complex II
Define:
Cytoplasm
Portion of the cell between the nucleus and plasma
membrane, including the membrane-bound organelles
Define:
Cytosol
• Portion of the cell between the nucleus and the plasma
membrane exclusive of the membrane-bound organelles;
• The cortical cytoplasm just under the plasma membrane
has a distinct arrangement of cytoskeletal elements which
excludes organelles and maintains the stiff gel form of the
cell.
What is:
A system of basophilic, membrane-bound, interconnected
tubules and flattened compartments within the cytosol
studded on its cytsolic surface with ribosomes.
Rough Endoplasmic Reticulum
Lipid synthesis occurs in association with the _______
leaflet of the ER.
cytosolic
Translocation to the luminal leaflet requires what protein?
flippases
N-linked or O-linked glycosylation:
• Connection of oligosaccharides through the hydroxyl group of
Threonine, serine, or hydroxylysine
• Occurs within the Golgi system
O-linked
N-linked or O-linked glycosylation:
- Connection of oligosaccharides to amino group of asparagine
- Begins in the ER
- Requires a dolichol carrier
N-linked
Functions of Smooth ER? (3)
• Detoxification (detoxifies lipid-soluble and water-soluble
substances into water-soluble compounds)
• Synthesizes phospholipids and cholesterol, which are
lipids necessary for turnover of cell membranes (both the
plasma membrane as well as the membranes of
organelles)
• Abundant in steroid-producing cells
Function of the Golgi Apparatus? (4)
- Sorts products into different pathways; Vesicles are targeted from Golgi apparatus to the apical or basolateral membranes of the cell.
- Location of posttranslational modifications
- Site for the assembly of proteoglycans
- Sulfation
Cis-face, Trans-face, or Medial compartment of Golgi:
- Site where most glycosylation takes place
- Subdivided into cis, medial, and trans compartments
Medial
vesicles transported from the RER to the Cis-Golgi are coated with?
COPII
What proteins contain the KDEL signal?
Vesicles being transported from Golgi to RER:
- These vesicles contain RER proteins that must be returned to the RER.
- The proteins contain a KDEL signal (Lys-Asp-Glu-Leu)
Vescicles being transported between cisternae of the medial compartment of the Golgi are coated with what?
COPI
vesicles leaving from the trans golgi face are coated with what?
• These vesicles are coated with clathrin which is removed shortly after
leaving the TGN.
Lysosomes are formed where?
Golgi apparatus
Lysosome membranes have:
A. Proteins that transport breakdown products into the
cytoplasm.
B. Hydrogen ion ATPase pumps
C. A and B
D. None of the above
C. A and B
Lysosomes can be formed via:
A. Endocytosis
B. Autophagy
C. Phagocytosis
D. All of the above
D. All of the above (formed, or pathway? go over)
Endocytosis:
• Small molecules are taken up by the cell and directed to vesicles called endosomes, which eventually form lysosomes
Autophagy:
• Worn-out organelles are broken down by lysosomal activity
Phagocytosis:
• Phagocytic vesicles are formed by cells specialized for the uptake of bacteria, viruses, and large particles.
Which type of exocytosis does not require a triggering reaction?
• Constitutive secretory pathway:
• Does not require a triggering reaction
- Selective exocytosis:
- Of stored granules
- Requires triggering signal
Which of the following bind to a primary lysosome to become a secondary lysosome?
A. Endosomes
B. Phagosome
C. Autophagosome
B. Phagosome
Endosome - Slide 22
Phagosome and Autophagosome - Slide 23
Which of the following reduces CoQ?
A. Complex 1
B. Complex 2
C. Complex 3
D. Complex 4
E. Complex 5
A. Complex 1
OUTLINE THE COMPLEXES, slide 26-28
Which has a higher affinity for electrons, Complex V or Complex II?
Complex V,
as you travel down the chain electron affinity MUST increase so that the electrons keep moving.
________ are associated with:
• ATP synthetase:
F1 particles
ATP synthesis
• Electron transport chain components
• Transport proteins
• Cardiolipin.
• Proteins for generation of energy and export and import
Cristae
What does Cardiolipin do?
increases the IMPERMEABILITY of the inner mitochondrial membrane
Which of the following is not in the mitochondrial matrix?
A. Mitochondrial DNA
B. Enzymes for the break-down of pyruvic acid, fatty acids,
and amino acids
C. Machinery for expression of mitochondrial genome
D. VDAD
D. VDAD
The function of the respiratory chain is to transport the ____ to
_____, leading to oxidative phosphorylation.
electrons, oxygen
Review figure 2-24
T/F: The inner mitochondrial membrane is impermeable to
hydrogen ions.
True
From Anaerobic to the end of aerobic respiration you start with _______
and end with ______.
Energy-rich glucose molecule,
End with: low energy carbon dioxide, water, and a lot of ATP
What does the endosymbiotic theory suggest?
that mitochondria evolved from prokaryotes
• Mitochondria may have been derived from α-proteobacteria which
were capable of oxidative phosphorylation.
• Instead of being digested, the α-proteobacteria may have been
retained as symbionts.
• Mitochondria have circular DNA (similar to prokaryotes).
T/F: Many mitochondrial genes may have been transposed to nuclear DNA.
True
T/F: You get your mitochondria from your father
False
• Mitochondrial DNA follows maternal inheritance patterns.
What is the function of Peroxisomes and what enzyme do they contain?
Catalase
• Catalase utilizes hydrogen peroxide as a substrate to oxidize
other molecules such as ethanol
• Oxidize a variety of substances to hydrogen peroxide (hence their
name) and break down hydrogen peroxide using catalase
• Synthesize lipids such as cholesterol
• Synthesize lysine
• Synthesize bile acids from cholesterol
