Flashcards in Cell biology I Deck (54):
What are the three constituents of the cell?
1) Organelles2) Inclusions3) Cytoplasmic matrix (cytosol)
What is the definition of cytoplasm?
The part of the cell external to the nucleus. It suspends organelles and inclusions
What is the region of the cell external to the nucleus, which suspends organelles and inclusions?
What is the definition of cytoplasmic matrix (cytosol)?
Portion of cytoplasm devoid of organelles and inclusions
What is the region of the cell that is devoid or organelles and inclusions?
Cytoplasmic matrix (cytosol)
What are inclusions?
Nonliving entities found in the cytoplasm and nucleus (e.g. food, pigments, crystalline)
Are inclusions membrane-bound?
Are proteins stored in the cytoplasm as inclusions?
Is glycogen an inclusion?
What stain would you use to detect glycogen?
What is McArdle Disease?
A disorder of glycogen storage caused by a genetic defect in muscle phosphorylase. It is specific to skeletal muscle.
McArdle Disease is specific to what type of muscle?
Is fat an inclusion?
Is carotene an inclusion?
Is carotene fat soluble or water soluble?
What is anthracosis?
Accumulation of carbon particles in lungs and regional lymph nodes. Harmless condition
Is hemoglobin an endogenous or exogenous pigment?
Where is hemosiderin usually found?
Macrophages of spleen and liver
What is hemosiderosis?
Increased deposition of hemosiderin in tissues
When is hemosiderosis usually observed?
1) Increased absorption of iron in diet2) Impaired use of iron by the body3) Hemolytic anemias4) Transfusions
What condition could be caused by increased absorption of iron in the diet?
What condition could be caused by impaired use of iron by the body?
What condition could be caused by hemolytic anemias?
What condition could be caused by transfusions?
What is hemochromatosis?
A more severe accumulation of iron due to a genetic defect, resulting in excessive iron absorption or transfusion
If hemosiderin is found in macrophages, what condition could be considered?
Congestive heart failure
What are 'heart failure cells'?
Macrophages filled with hemosiderin
Macrophages filled with hemosiderin are referred to as ___________.
Heart failure cells
Where is melanin found?
Membrane-limited granules in the epidermis and pigment layer of retina
What pigment is found in membrane-limited granules in the epidermis and pigment layer of the retina?
What are two endogenous forms of melanin?
1) Eumelanin2) Neuromelanin
Where is neuromelanin normally found?
Substantia nigra of brainstem (also locus coeruleus)
What is phaeomelanin?
Red pigment responsible for red hair color
Does melanin increase or decrease in Addison's disease?
Why does melanin increase in Addison's disease?
Melanin stimulating hormone (MSH) and adrenocorticotropic hormone (ACTH) share the same precursor molecule. Increased ACTH from adrenal insuffiency causes increased MSH levels as well (hyperpigmentation of areas exposed to UV light
A lack of tyrosinase in albinos leads to a lack of what pigment?
Is neuromelanin membrane-limited?
What is lipofuscin (lipochrome pigment)?
Brownish-yellow pigment that is an amalgam of lipids, metals, and organic molecules (the wear-and-tear pigment)
What is the "wear-and-tear" pigment?
What pigment accumulates in long-lived cells?
Accumulation of lipofuscin is indicative of what cellular conditions?
Cellular stress - malnutrition, cachexia (wasting syndrome)
Where are crystalline inclusions usually found?
1) Cells of Leydig (crystal of Reinke)2) Sertoli cells (inclusion of Charcot-Bottcher)
What is the plasmalemma?
The dynamic organelle that separates the cell's internal environment from its external environment
How much of the cell is made up of the plasmalemma?
How thick is the plasmalemma?
What three types of lipids make up the plasmalemma?
1) Phospholipids2) Glycolipids3) Cholesterol
What is the most abundant lipid in the plasmalemma?
What does cholesterol do to the plasmalemma?
Strengthens / makes it less deformable (but makes it less permeable to small, water soluble molecules)
What are lipid rafts?
Areas in the plasma membrane where sphingolipids and cholesterol are concentrated
What is the primary function of lipid rafts?
What is the function of simvastatin?
Decreases the amount of cholesterol and thus raft formation, leading to apoptosis (reduced rafts decreases Akt, which is a cell survival protein kinase molecule)
What is Akt?
A cell survival protein kinase molecule
What does a reduction in cholesterol do to lipid raft formation?