Biology 140 Final Exam

approximately neutralIn order for phospholipids to form bilayers spontaneously in an aqueous environment, the pH should be: - approximately neutral Which choice is considered an integral membrane protein? - a protein with its amino-terminus in the cytoplasm and its carboxy-terminus in the extracellular space In intestinal epithelial cells, a transport protein moves the bulky, polar glucose molecules through the membrane into the cytoplasm, while simultaneously transporting Na+ through the membrane into the cell down its electrochemical gradient. Which example correctly describes this cotransport of glucose and sodium? - secondary active transport by a symporter What would be found in the cells of a blade of grass but not in the cells of an insect feeding on that grass? - chloroplasts Which statement is true about the presence or absence of plasma membranes? - All cells have a plasma membrane. A cell has a mutation that prevents it from breaking down unwanted proteins present in vesicles. Which cellular structure is most likely to be disrupted by this mutation? - Lysosomes RNA molecules are transported from the nucleus to the cytoplasm in eukaryotes through: - nuclear pores During translation, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal sequences. Which sequence would you expect to find in the signal sequences that will eventually become enzymes important in photosynthesis? - an amino-terminal signal sequence Which of the structures are part of the endomembrane system? - the nuclear envelope Which of the answer choices is not considered to be a part of the endomembrane system? - Mitochondria Most elements of the endomembrane system are connected by: - vesicular trafficking Consider a protein that is targeted to be excreted to the outside of the plasma membrane. - in the lumen (inside) of the E.R Consider a protein that is targeted to be excreted to the outside of the plasma membrane.