Dr. Mhawi 3 Cell Organelles Flashcards
_______ are present in large numbers in hepatocytes and absent in mature erythrocytes and terminal keratinocytes
Mitochondria
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Describe the inner and outer membrane of mitochondria
In the mitochondria, the _______ contains specific enzymes like cytochrome c that plays an important factor in apoptosis initiation
Intermembrane space
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Describe this image
What is this image of mitochondria depicting?
Two types of cristae: tubule- or vesicle-like and plate-like.
Most cells contain mitochondria with plate-like cristae. Steroid secreting cells (e.g. Adrenal, gonadal cells) have tubulo-vesicular cristae
What are the two types of ER’s
Rough (rER; ribosomes attach to outer surface)
Smooth (sER; outer surface ribosomes-free)
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With TEM: rER appears as series of membrane-limited, flattened sacs called ______
cisternae
What is the 2 main functions of rER?
protein synthesis
post-translational modification of newly synthesized proteins
In the cytosol many ribosomes are connected by one strand
of mRNA (aka _______)
■ Found in two forms:
Free polysomes: free in the cytosol
Bound polysomes: attach to the outer surface of rER
cisternae
■ Synthesize different classes of proteins
polysomes
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True or False: Ribosomes responsible for basophilia in LM
True
Explain this image
The cytoplasm of this cell is occupied by rER. Note the electron-dense particle (arrows) which represent the membrane-bound ribosomes. The ribosomes attach to the outer surface of the rER cisternae. The Lumina of some of the rER cisternae are indicated.
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Explain this image
Transmission electron micrograph (TEM) of the cytoplasm of two adjacent protein-producing cells. The cytoplasm of these cells is filled with rER. Black solid arrows point to the free ribosomes. Red arrows indicate the rER-bound ribosome. The blank arrows are pointing to the ribosome-free plasma membranes of the two adjacent cells.
- _____ are a group of flattened sacs, with vesicles around the margins
- Prominent in protein-secreting cells
- At the TEM level appears to consists of three defined
regions: cis, medial, and trans
Golgi
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At LM level Golgi apparatus appears as a lightly stained are in the cytoplasm of the protein-producing cells (e.g., plasma cells; this light micrograph
Light micrograph of group of plasma cells present in most likely infected tissue. The light regions of the cytoplasm (indicated by the arrows) represent Golgi complex in the cytoplasm of plasma cells.
Explain this image
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Explain this image
TEM of steroid producing cell. The cytoplasm of the cell is occupied with well-developed smooth endoplasmic reticulum (sER). L, lysosome; M, mitochondrion.
What are the main functions of the sER?
―Biosynthesis of steroid hormones
―Biosynthesis of membrane lipids
―Breakdown of toxins and drugs
―Synthesis of triglycerides from monoglycerides in the intestinal epithelium
―Sequestering of calcium in striated muscle (sarcoplasmic reticulum)
Smooth endoplasmic reticulum in striated muscle fibers is called _______ reticulum
Responsible for storage of Ca++ ions
sarcoplasmic
_______ are membrane-bound organelles containing a large variety (40) of acid hydrolases (i.e., enzymes work in acidic pH)
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Lysosomes
•Profound in neutrophils and macrophages
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What are teo ways the material is brought to the lysosomes?
•Heterophagy
–Endocytosis
–Phagocytosis
•Autophagy
–Degradation of cell’s senescent organelles and large denatured protein
Explain this image
Lysosomes (L) in macrophage. When the lysosome fuses with phagosome (P) the combined structure is called phagolysosome. In the phagolysosome the content of the phagosome is degraded by the hydrolytic enzymes of the lysosome.
Indigestible compounds stored in the lysosomes are called _______
The unreleased indigestible compounds in long-living cells are called _______
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residual bodies
aging pigments
_________- Absence of lysosomal galactosidase (B-hexosaminidase) in neurons
–Produces concentric lamellar structures in the lysosomes
–Interferes with normal neuronal function
•Tay-Sachs disease
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________ is lack of enzyme that breaks down glycolipids, glycolipids accumulate, enlarged liver and spleen
________ is lack of acid maltase (has glycogen substrate, glycogen accumulates in liver and muscle
_______ is defective degradation of cerebral gangliosides (enzyme replacement)
- Gaucher’s Disease
- Pompe’s Disease
- Niemann-Pick Disease
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