MOLECULAR BIOLOGY OF THE CELL questions and answers

prokaryote - Answer-no nuclear membrane, no organelles except ribosomes, circular DNA, usually bacteria .how quickly can prokaryotes reproduce - Answer-every 20 mins .eukaryote - Answer-cell with organelles and DNA, can be unicellular or multicellular .what is the cytoskeleton composed of - Answer-microtubules, actin filaments and intermediate filaments .cell membrane of eukaryote - Answer-double membrane around the nucleus, selectively permeable, phospholipid bilayer, fluid mosaic model .fluid mosaic model - Answer-proteins and phospholipids can move laterally .describe the physiology of mitochondria - Answer-smooth outer membrane, permeable to ions and small molecules, glycolipids and glycoproteins, highly folded inner membrane (cristae) which is impermeable .define glycolipid - Answer-lipids with a carbohydrate attatched to them - increases cell stability .glycoproteins define - Answer-proteins with a carbohydrate attached .mitochondrial matrix - Answer-the part of the mitochondria which does not contain membranes - contains DNA .endoplasmic reticulum - physiology - Answer-network of sacs and tubules (cisternae) .endoplasmic reticulum - function - Answer-rough ER - ribosomes - protein synthesis smooth ER - no ribosomes - lipid synthesis .golgi apparatus - physiology - Answer-flattened sacs - pancake stack .golgi apparatus - function - Answer-synthesise and package molecules to be secreted from the cell .what is the cell membrane permeable to - Answer-small hydrophobic and small uncharged polar molecules - eg. o2, co2, N2, benzene, h2o, glycerol, ethanol .what is the cell membrane impermeable to - Answer-large uncharged polar molecules - eg. amino acids, glucose, nucleotides, h+, NA+, HCO3-, K+, Cl-