Cell Ultrastructure Flashcards
Describe the nucleus
How many membranes?
What is in the nucleus?
Double nuclear membrane
Contains DNA in the form of chromatin within the nucleolus
What is chromatin?
Long thread of DNA wound around histone proteins
What are the 2 types of chromatin & describe them?
Euchromatin = loose coils, expressed (DNA transcription can occur)
Heterochromatin = tight coils, DNA is repressed, not transcribed & translated
What happens in the nucleolus?
rRNA synthesis (production of ribosomes)
What is the function of the mitochondria?
How many membranes does it have?
ATP synthesis
Has a double membrane
Describe & explain the function of the inner & outer membrane of mitochondria
Inner membrane = highly folded, electron transport chain, ATP production
Outer membrane = lip synthesis & fatty acid metabolism
What occurs in the matrix and intermembranous space of mitochondria?
Matrix = Krebs cycle
Intermembranous space = nucleotide phosphorylation (ADP to ATP)
What is the function of smooth ER?
Sire of membrane lipid synthesis
Processes & stores proteins
Phase 1 detoxification (getting rid of drugs)
What’s the function of rough ER?
Increased no of ribosomes
Protein synthesis
What are the 3 types of Golgi apparatus and their function?
Cis (first)- receives protein/lipid vesicles
Medial (middle)- modifies products by adding sugars to these
Trans (last)- package modified molecules into vesicles, exocytosed
Where is the Golgi apparatus located?
Close to the nucleus of the cell
In most cells, the Golgi apparatus cannot be seen, however seen clearly in plasma cells, why?
Perinuclear huff
What are 2 examples of vesicles?
Lysosomes and peroxisomes
What do lysomes do & contain?
Degrades proteins + cell autolysis (recycling)
Low pH inside cell- pH5 maintained by H+/K+ ATPase (pump H+ ions into cell)
Contains digestive enzymes
What are the functions of peroxisomes?
B oxidation of fatty acids
Produces and destroys H2O2
Removes H from lipids/alcohol/toxic substances
