Flashcards in Exam #1: Cell Biology I Deck (27)
What are the three cellular constituents?
3) Cytoplasmic Matrix (Cytosol)
What are organelles?
Structural elements that confer functional attributes to the cell (membranous vs. non-membranous)
What is the definition of the cytosol or cytoplasmic matrix?
- Cytosol is the portion of cytoplasm devoid of organelles & inclusions
- Cytoplasm is everything outside of the nucleus
What are inclusions?
Nonliving entities found in the cytoplasm & nucleus that are not bound by a membrane
- Stored foods
What two foods are stored as inclusions, and which is not?
1) Glycogen (Carbohydrate)
2) Lipids (Fat)
- Protein is not stored as an inclusion
- Stored as an inclusion
- Abundant in liver & striated muscle
- Demonstrated by the PAS reaction
- Accumulation of glycogen under the sarcolemma
- Symptoms include: cramping, exercise intolerance, myoglobin & creatine kinase elevations with exercise
- Caused by a defect in muscle glycogen phosphorylase
Fat (lipid) Droplets
- Found in adipocytes, hepatocytes, muscle, & steroid secreting cells
- Accumulation in lipid storage disease & fatty liver
What are exogenous pigments?
Pigments that come from outside the body
2) Inhaled Dust
- Fat soluble orange colored pigment
- Carotene is found in CARROTS, sweet potatoes, & squash
- Responsible for the yellow-orange color of fat
- Build-up of carotene that follows prolonged and excessive consumption of carotene-rich foods, such as carrots, squash, and sweet potatoes
- Harmless & reversible
- Often mistaken for jaundice
- Accumulation of carbon particles in the lungs & regional lymph node
Where are tattoo pigments stored?
Macrophages in the dermis of the skin
What are endogenous pigments?
Pigments that come from within the body
What is hemosiderin?
- Brown iron storage protein that is found in macrophages of the spleen & liver
- Stained with prussian blue
- Accumulates in macrophages in CHF
- Increased deposition of hemosiderin in tissues
- Seen with increased iron in diet, impaired use of iron in the body, hemolytic anemia, & transfusions
Severe accumulation of iron due to a genetic defect resulting in excessive iron absorption or transfusion
What are the three different types of melanin?
- Black-brown pigment
- Found in membrane limited granules of the epidermis & retina
- Increased production in response to UV
- Black-brown pigment found in neurons
- Esp. Substantia Nigra
- Loss in PD
- Red pigment of skin & hair
- NOT protective against UV radiation
- The aging pigment
- Yellow-brown insoluble pigment
- Indication of "wear & tear"
- Polymer of lipids and phospholipids complexed with proteins
- Accumulation is a measure of oxidative stress
- Accumulates in long-lived cells i.e. heart & neurons
What are nuclear inclusions an indication of?
What are Reinke & Charcot-Bottcher inclusions, and where are they found?
- Crystalline Inclusions
- Testis ( Cell of Leydig & Sertoli cells)
What are lipid rafts?
- Signaling platform
- Small area where sphingolipids & cholesterol are concentrated
- B/c this area is thick & molecularly unique, proteins aggregate here
- Protein aggregation lends itself to signal transduction
How do lipid rafts change in cancer?
Increase in cholesterol, which increases lipid rafts