BIO 264 Exam 2 Review: Electrophysiology and Ion Channels, Exams of Biology

Download BIO 264 Exam 2 Review: Electrophysiology and Ion Channels and more Exams Biology in PDF only on Docsity! 1. Which ion has greatest influence on resting membrane potential? Potassium 2. Concerning resting membrane potential, the inside of the membrane is compared to the charged outside negative, positively. 3. T or F: The diffusion of K+ and Na+ down their chemical gradients contributes to the resting membrane potential False 4. At resting membrane potential, . extracellular sodium levels are high 5. During the hyperpolarization phase… K+ leaves the cell 6. Which is not a characteristic of a graded potential? A) Spreads in a decremental fashion B)Can result from changes in voltage across the membrane C) Can summate D) Size is inversely proportional to stimulus strength 7. As the stimulus strength and size of the graded potential the action potential frequency . increases; increases 8. The outside of a cell during resting membrane potential is in relation to the inside of the cell. Positively charged 9. If at resting membrane potential (RMP), the plasma membrane becomes more permeable to K+, the cell would . hyperpolarize 10. Which ion has greatest influence on resting membrane potential? K+ 11. Which statement is true? A) ATP is required to move Na+ extracellularly B)Ca+ binding to specific ion channels stops the intracellular diffusion of Na+ C) Na+ relies on a specific type of ion channel for diffusion D) All are true E) Two are true F) None are true 12. If extracellular concentration of K+ increases, what will the effect be on the resting membrane potential? The increase in extracellular K+ concentration will decrease the normal K+ gradient; because of this K+ has less of a tendency to diffuse out of the cell. The resting membrane potential becomes less negative (depolarizes). 13. If you increased the concentration of extracellular Na+ of a membrane at resting membrane BIO 264 Exam 2 review 2024 Updated Exam!! potential, what would happen? hardly any change in the membrane potential 14. If a cell membrane became more permeable to Na+ what would happen to the resting membrane potential? Na+ diffuses into the cell causing depolarization. BIO 264 Exam 2 review 2024 Updated Exam!! 30. During the course of the action potential, the membrane POTENTIAL changes from negative to positive to negative relative to the outside of the cell 31. During depolarization, membrane permeability is greatly increased to which of the following ions? Na+ 32. Which of the following is true regarding an action potential? it occurs when the local potential reaches threshold 33. Which statements are true? -The purpose of the Na+, K+ ATPase pump is to maintain concentration gradients of Na+ and K+. -The brain prefers to use action potentials, but can function using other forms of communication like ketones. -If a graded potential does not hit threshold it will never become an action potential. 34. Which statement is true regarding ion concentrations across a resting membrane? K+ concentration is greater intracellularly and Na+ concentration is greater extracellularly. 35. When a cell is in the depolarization phase.. a new action potential is possible provided the repolarization potential value is lower than threshold 36. How is a cell repolarized after stimulation? by K+ flowing out of the cell 37. Which is true regarding voltage-gated K+ channels? -They only have one gate. -They are slower to open than Na+ channels. -They stay open until repolarization is complete. -They only allow K+ ions to flow through them. 38. What occurs during depolarization? There is a rapid influx of Na+ ions. 39. Define threshold the critical level of depolarization that must be achieved to fire an action potential 40. What is an action potential? An action potential is an electrical impulse that travels down the axon, leading to neurotransmitter release 41. Define membrane potential difference in electrical charge between the inside and outside of a cell 42. Define resting potential steady membrane potential of -70mV, and in this state with the -70 mV charge built up across its membrane it is said to be POLARIZED 43. less then -70 mV DEPOLARIZED 44. More than -70 mV HYPERPOLARIZED 45. Ionic basis of resting potential BIO 264 Exam 2 review 2024 Updated Exam!! In resting neurons, there are m ore Na+ ions outside the cell then inside, and more K+ ions inside than outside 46. Phagocytosis uses , while Pinocytosis uses . Pseudopodia/ invaginations 47. Which type of protein extends through the full width of the cell membrane? integral proteins BIO 264 Exam 2 review 2024 Updated Exam!! 48. Which of the following statements about diffusion of charged molecules are TRUE. 1 - Passive Diffusion of non-charged particles across a cell membrane continues until concentrations come to equilibrium 2 - Passive Diffusion of potassium (positive charge) across a membrane continues until concentrations come to equilibrium. 3 - Diffusion is faster if the temperature is decreased 4 - Diffusion is faster across a cell membrane if the surface area is increased 5 - Membrane permeability depends only on the molecules size 6 - Diffusion of ions across a cell membrane requires a protein channel or transporter 1,4,6 49. Which is not a characteristic of mediated transport? competition saturation tonicity specificity 50. Small pieces of matter, and even whole cells, can be transported across the plasma membrane in Vesicles 51. Which is true in regard to concentration gradients? The greater the difference between areas of high concentration and low concentration, the greater the rate of diffusion. 52. The rate of diffusion increases if the viscosity of a solution decreases. BIO 264 Exam 2 review 2024 Updated Exam!!