Bio 3324 1nd EditionExam # 1 Study Guide Chapters: Unit oneUnit 1 (August 27-9-17)Understand the cell membraneFunctions of membrane transportCell signaling/signal transductionKnow what action potentials Unit one possible exam questions:1) Which of the following statements concerning the plasma membrane is correct?a) It is more permeable to Na+ than K+ at resting stateb) Serves as a barrier to the passage of water soluble substances through the membranec) Is primarily made up of proteins, cholesterol and carbohydrate chainsd) All of these statements are correcte) None of these statements are correct2) Which of the following is not a function of membrane proteins?a) They serve as channelsb) They determine the fluidity of the membranec) They serve as carriersd) They serve as receptor sitese) They can have enzymatic activity3) Which type of protein enables the passage of small ions through the plasma membrane?a) Carrier protein.b) Cell adhesion molecules (CAMs).c) Channel protein.d) Enzyme proteins.e) Receptor proteins.4) Selective permeability of the membrane is primarily determined by:a) membrane phospholipidsb) how much cholesterol is presentc) the number and type of membrane proteinsd) the charge of the membranee) all of these answers5) When equilibrium is achieved and no net diffusion is taking place, there is no movement of molecules.a) Trueb) False6) Which term best describes the membrane of an excitable cell when a resting potential is present?a) depolarizedb) hyperpolarizedc) nonpolarizedd) polarizede) repolarized7) The negative charge established along the nerve cell membrane is due to:a) movement of Na+ into the cellb) movement of proteins out of the cellc) higher permeability of K+ relative to Na+d) intracellular protein anionse) both (c) and (d)8) Which of the following is not responsible for the resting membrane potential in excitable neural cells:a) Anionic cellular proteinsb) Calciumc) Potassiumd) Sodiume) All of these are responsible.9) The cells of excitable and nonexcitable tissues share which of the following properties?a) a threshold potentialb) an ability to open Na+ gated channelsc) a resting membrane potentiald) all of thesee) none of these10) Net potassium movement into a cell occurs passively, whereas net potassium movement outof the cell occurs actively.a) Trueb) False11) Permeability of which ion is affected by a positive feedback mechanism once threshold is reached?a) sodiumb) potassiumc) calciumd) chloridee) anionic protein12) An action potential develops when:a) Threshold voltage is reachedb) Voltage-gated Na+ channels open and the membrane reaches about -55 mVc) Spatial and/or temporal summation of graded potentials occurs to a great enough extentd) Depolarization of the axon occurse) All of these.13) During the falling phase of the action potential which of the following is true:a) Voltage-gated Na+ channels are open and sodium is flowing into the cell.b) Voltage-gated Na+ channels are open and sodium is flowing out of the cell.c) Voltage-gated K+ channels are open and potassium is flowing into the cell.d) Voltage-gated K+ channels are open and potassium is flowing out of the cell.14) A stronger stimulus above threshold produces a greater action potential than normala) Trueb) False15) Action potentials can be summed.a) Trueb) False16) If a neuron were experimentally stimulated at both ends simultaneously,a) The action potentials would pass in the middle and travel to the opposite endsb) The action potentials would meet in the middle and then be propagated back to their startingpositionsc) The action potentials would stop as they met in the middled) The strongest action potential would override the weaker action potentiale) Summation would occur when the action potentials met in the middle, resulting in a larger action potential. 17) Saltatory conduction:a) occurs in unmyelinated nerve fibersb) involves the impulse jumping from one node of Ranvier to the adjacent nodec) is slower than contiguous conduction because myelin acts as an insulator to slow the impulse downd) refers to the action potential spreading from one Schwann cell to the adjacent Schwaan cell18) Which of the following is not true of contiguous conductiona) occurs in unmyelinated nerve fibers.b) the action potential must travel the full length of the axonal cell surface.c) is slower than saltatory conduction d) All of these.e) None of these.19) In convergence:a) Thousands of synapses from many different presynaptic cells end upon a single postsynaptic cell.b) The axon of a nerve cell branches so that the activity in one neuron influences many other cells.c) The dendrites all converge upon the cell body.d) All of these answers.e) None of these answers.20) The grand postsynaptic potential depends on the sum of activity of the presynaptic inputs.a) Trueb) False21) Which of the following statements is false regarding steroid hormonesa) Cholesterol is the common precursor for all steroid hormonesb) Are lipid solublec) Must bind carrier proteins in the blood to be transportedd) Specific enzymes are needed to synthesize specific steroids in each of the steroidogenic organse) Are packaged and stored until needed22) Which of the following is not a second messenger molecules?a) cAMPb) calcium (Ca2+)c) DAGd) ATPe) All of these23) Lipophilic hormones usually bind cell surface receptorsa) Trueb) FalseAnswers:1) B 7) E 13) D 19) A2) B 8) B 14) B 20) A3) C 9) C 15) B 21) E4) C 10) B 16) C 22) D5) B 11) A 17) B 23) B6) D 12) E 18)