Cell Ultrastructure Flashcards
Why are electron microscopes capable of finer resolution than light microscopes?
Limit of resolution is proportional to wavelength. Electrons have a much smaller wavelength than light.
What is the limit of resolution.
Minimum distance between two objects for them to be discerned as separate objects.
What is the structure of the plasma membrane?
Phospholipid bilayer (glycerol bound to two fatty acids, and a phosphate bound to choline) Proteins embedded in the membrane.
What property does a phospholipid have?
It is amphipathic
What makes up the glycocalyx?
Oligosaccharides and polysaccharides on the outside of the plasma membrane.
What are the functions of the plasmalemma?
Exocytosis Endocytosis Transport of proteins along the cell surface Signal transduction Intercellular adhesion Intercellular recognition Selective permeability
Where is smooth endoplasmic reticulum found?
Liver and mammary gland - synthesis of lipids
Ovary, testes, adrenal gland - steroidogenesis
At which face of the Golgi apparatus do vesicles arrive?
Cis.
At what face of the Golgi apparatus are vesicles secreted?
Trans
What are the possible destinations of vesicles from the Golgi?
Constitutive secretion
Regulated secretion (storage)
Lysosomes
What enzymes are contained in a lysosome?
Nucleases, proteases, glycosidases, lipases, phosphatases, sulphatases, phospholipases.
Where are peroxisomes found?
Cells of the liver and kidney.
What is the function of peroxisomes?
Oxidise alcohols, phenols, formaldehyde, formic acid.
Can mitochondria divide?
Yes
What is the primary function of mitochondria?
Synthesis of ATP by oxidative phosphorylation.
