33 Different glycoproteins can have a diverse array of oligosaccharides. Which of the statements below for making glycoproteins on plasma membrane is true?
(a) Extensive modification of oligosaccharides occurs in the extracellular space.
(b) Initial oligosaccharide chains are made by addition of one sugar at a time onto the protein in the ER lumen.
(c) Each layer of Golgi membrane structures contains identical modification enzymes for modifying sugar chain on proteins.
(d) ER lipids can be modified by sugar chain, which can be used for sugar chain modification of the proteins.
34 In a multicellular organism, when a signal needs to be sent to most cells the signal most suited for this is a ___________.
(a) neurotransmitter.
(b) hormone.
(c) dissolved gas.
(d) plasma membrane anchored ligands.
35 Typically, members of the steroid hormone receptor family __________________.
(a) are cell-surface receptors.
(b) do not undergo conformational changes by binding to their ligands.
(c) are found mainly in the nucleus when ligand is not available.
(d) interact with signal molecules that diffuse through the plasma membrane
36 Which of the following statements about what happens when a G-protein-coupled receptor activates a hetero trimeric G protein is true?
(a) The β subunit exchanges its bound GDP for GTP.
(b) The GDP bound to the α subunit is phosphorylated to form bound GTP.
(c) The α subunit exchanges its bound GDP for GTP.
(d) It activates the α subunit and inactivates the βγ complex
37 Which of the following statements about signal transduction is false
(a) Ca2+ concentration in cytosol will increase when PLC (Phospholipase C) is activated by signal.
(b) Cyclic GMP is made in smooth muscle cells when they received NO signal.
(c) SH2 domain containing proteins can be expected to interact activated RTK.
(d) Ligand binding to RTK activates its enzyme activity then the activated RTK phosphorylates tyrosine residues on itself.
