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66 Cards in this Set
- Front
- Back
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Describe the cell membrane or plasmalemma.
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8 to 10 nm in width, it is trilaminar
It consist of two leaflets of phospholipid molecules. |
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Proteins associated with the lipid bilayer may be:
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integral transmembrane protein or peripheral membrane protein.
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The --------- is present in the external leaflet of the cell membrane, which protects the cell from mechanical and chemical damage.
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glycocalyx coat (glycolipid and glycoprotein)
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What are some functions of cell membranes?
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Selectively permeable, antigen receptor sites
receptor sites for hormone activated cellular events. |
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Nucleus is bounded by the -------- and contains what?
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nuclear envelope
chromatin, nucleolus or nucleoli and a nuclear matrix. |
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Normally cells contain one nucleus, but_______ and ______ have several nuclei.
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skeletal muscle cells and osteoclasts
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What do Mammalian erythrocytes lack?
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nuclei
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Nuclear envelope consist of what?
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two concentric membranes
0uter-ribosomes/RER Inner-membrane proteins |
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What is chromatin composed of?
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(DNA), proteins, histones and nonhistone chromosomal proteins.
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Chromatin occurs in two forms, what are they?
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Heterochromatin in basophilic clumps predominant in relatively inactive cells.
Euchromatin particularly abundant in active cells, lightly stained and uniformly dispersed. |
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_________ Chromatin occurs in basophilic clumps predominant in relatively _________ cells.
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Heterochromatin, inactive
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_________ Chromatin is particularly abundant in active cells
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Euchromatin,
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What chromatin is prominent in neutrophilic leucocytes in females ?
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sex chromatin (Barr body)
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Where are nucleolus prominent?
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In cells that are actively synthesizing protein.
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What is the nucleolus responsible for doing?
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Involved in the synthesis of rRNA and its packaging into precursor of ribosomes.
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All cells except __________ contain ribosomes.
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mature mammalian erythrocytes
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What are the function of ribosomes?
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protein synthesis
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What are ribosomes mainly associated with?
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Rough E.R
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Aggregates of roughER appear as basophilic and are involved in what ?
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protein synthesis.
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Smooth ER is abundant in cells involved in ________.
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lipid metabolism (synthesis of steroid hormones).
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The enzymes for synthesis of _________ are located on the membranes of smooth ER.
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steroid hormones
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Smooth ER is also involved in __________ and release and recapture of __________ during contraction and relaxation of muscle tissue.
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drug detoxification, calcium ion
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Golgi complex can be stained with _________ and appears as a black network of cisternae.
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silver salt or osmium
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What is the function of the Golgi complex?
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Site for the packaging of proteins
Biosynthesis of glycoprotein |
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What are lysosomes?
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membrane-bounded vesicles that contain hydrolytic enzymes (kills Microorganisms)
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Where are lysosomes synthesized and where are they transferred?
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synthesized in the rER and transferred to the golgi complex-enzymes are packaged as primary lysosomes.
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What are the differences between primary lysosomes and secondary lysosomes?
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The primary lysosomes fuse with the phagocytosed material autophagy); to become secondary lysosomes.
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What happens to secondary lysosomes after digestion?
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retained as residual bodies or lipofuscin (age pigment).
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What are peroxisomes?
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organelles, that have oxidase and catalase enzymes which synthesize and destroy hydrogen peroxide.
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Where are peroxisomes abundant?
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hepatocytes
proximal convoluted tubules of the kidney. |
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What is the major function of peroxisomes?
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detoxify certain substances e.g. ethanol and play a role in gluconeogenesis.
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Mitochondria is stained with _________ in living cells.
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Janus Green B
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What is the function of the mitochondria?
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metabolic activity in the cell
chief source of energy. |
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What are the inner membranes of the mitochondria composed of?
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folds (cristae) contain enzymes for oxidative phosphorylation.
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Which energy cycle is the mitochondria involved in.
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oxidative phosphorylation
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The mitochondrial matrix contains ___________.
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DNA and ribosomes
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What is the only cell organelle outside the nucleus that contains DNA?
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Mitochondria
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What is the cytoskeleton composed of?
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microfilaments, intermediate filaments and microtubules
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What are microfilaments?
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made of actin and myosin filaments
used for muscle contraction |
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__________ are present in almost all cells - abundant in cells subject to mechanical stress.
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Intermediate filaments
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________ filaments provide mechanical stability by formation of desmosomes. Also present in keratinized epithelium for protection
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Keratin filaments (Tonofilaments)
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________ filaments support muscle cells.
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Desmin filaments
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_______ filaments support nerve cells.
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Neurofilaments
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__________ filaments support astrocytes and neurolemmocytes (Schwann cells).
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Glial filaments
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What are microtubules and what major role do they play in the cell?
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They are tubular structures that help w/ the maintenance of cell.
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_________ play an essential role in cell division and are the major component of the centriole.
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Microtubules
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___________play an essential role in cell division and are the major component in the maintenance of the cell.
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microtubule
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What are cytoplasmic inclusions? Give 5 examples.
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non-living material
Glycogen, Lipid, melanin, Hemosiderin, Lipofuscin |
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___________ is a cytoplasmic inclusion in liver cell and muscle, can be demonstrated by PAS reaction.
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Glycogen
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_________ is a cytoplasmic inclusion in adipose cells.
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Lipid
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_________ is a cytoplasmic inclusion in skin, pigment epithelium of retina.
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Melanin
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_________ is a cytoplasmic inclusion that is a result of hemoglobin degradation.
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Hemosiderin
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Which cytoplasmic inclusion increases with age?
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lipofuscin
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What is Lipofuscin and where is it found?
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It is indigestible residue of phagocytosis, commonly found in cardiac muscle, liver and nerve cells.
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What are intercellular junctions and give 3 examples.
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They help keep cells together.
tight junction, adhering (anchoring) junctions, gap junction |
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What are tight junctions and where are they found?
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epithelial cells and consist of (transmembrane proteins) that seal neighboring cells together.
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Describe the function of a tight junction.
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barrier that prevents the passage of water soluble molecules from the lumen to intercellular space and vice versa.
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What are the 3 types of adhering (anchoring) junctions?
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Zonula adherens, Desmosomes, Hemidesmosomes
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_________ are intercellular junctions prominent in the lining cells of the intestine.
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Zonula adherens
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Intermediate filaments are attached to __________ forming a hairpin loop
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Desmosomes
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They connect the cells from extracellular matrix protein (similar to the half desmosome).
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Hemidesmosomes
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__________ are required when passing something from one cell to another.
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Communicating (gap) junction
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What are communicating (gap) junctions?
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Permits the direct passage of inorganic ions and other water-soluble molecules from cell to cell.
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A single long cilium is reffered to as a __________.
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flagellum, e.g., spermatozoon
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__________ are cytoplasmic evagination to increase the free surface for absorption, e.g., small intestine
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Microvilli
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__________ are long, rigid microvilli. e.g., hair cells of the spiral organ (corti) of the inner ear.
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Stereocilia:
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