Lehninger's Biochemistry Chapter 11| Questions and Answers with complete

Which one of the following statements about membranes is true? A) Most plasma membranes contain more than 70% proteins. B) Sterol lipids are common in bacterial plasma membranes. C) Sterol lipids are common in human cell plasma membranes. D) Sterol lipids are common in plant cell plasma membranes. E) The plasma membranes of all cell types within a particular organism have basically the same lipid and protein composition. - C The inner (plasma) membrane of E. coli is about 75% lipid and 25% protein by weight. How many molecules of membrane lipid are there for each molecule of protein? (Assume that the average protein is Mr 50,000 and the average lipid is 750.) A) 1 B) 50 C) 200 D) 10,000 E) 50,000 - C Which of these statements about the composition of biological membranes is false? A) In a given eukaryotic cell type (e.g., a hepatocyte), all intracellular membranes have essentially the same complement of lipids and proteins. B) The carbohydrate found in membranes is virtually all part of either glycolipids or glycoproteins. C) The plasma membranes of the cells of vertebrate animals contain more cholesterol than the mitochondrial membranes. D) The ratio of lipid to protein varies widely among cell types in a single organism. E) Triacylglycerols are not commonly found in membranes - AWhich of these statements about the composition of membranes is true? A) All biological membranes contain cholesterol. B) Free fatty acids are major components of all membranes. C) The inner and outer membranes of mitochondria have different protein compositions. D) The lipid composition of all membranes of eukaryotic cells is essentially the same. E) The lipid:protein ratio varies from about 1:4 to 4:1 - C