Nerve Impulses Activity 1: The Resting Membrane Potential 1. Explain why increasing extracellular K+ reduces the net diffusion of K+ out of the neuron through the K+ leak channels. Increasing the extracellular K+ causes the membrane potential to change to a less negative value because when K+ ions diffuse out across the membrane they are leaving behind a net negative charge. 2. Explain why increasing extracellular K+ causes the membrane potential to change to a less negative value.
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After doing so‚ the procedure to removing the lead is called “chelation therapy”. Chelation therapy is when a doctor prescribes a medicine to the patient to bind with heavy metals‚ like lead‚ in the body and neutralize their reactive potential‚ so they can be excreted through the urine. A common chelating agent is dimercaprol‚ which is effective because of its sulfhydryl group. Lead tends to react with enzymes that have sulfhydryl groups‚ so the dimercaprol binds with the lead rather than
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Exercise 3: Neurophysiology of Nerve Impulses: Activity 1: The Resting Membrane Potential Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. What is the approximate concentration of K+ inside a typical cell (intracellular concentration)? You correctly answered: a. 150 mM 2. What is the approximate concentration of K+ outside a cell (extracellular concentration)? You correctly answered: b. 5 mM 3. What is the approximate concentration of Na+ inside
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the increase in water pressure within the cell) in plant cells. Turgor pressure prevents further osmosis‚ which causes the water potential outside the cell to be lower than that inside the cell. When placed in a hypertonic environment‚ the gradient in animal and plant cells are reversed and water exits the cell. This sudden release of water results in a shrinking membrane‚ called crenation‚ which
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w w w e tr .X m eP e ap .c rs om June 2003 GCE A AND AS LEVEL MARK SCHEME MAXIMUM MARK: 40 SYLLABUS/COMPONENT: 9700/01 BIOLOGY Paper 1 (Multiple Choice) Page 1 Mark Scheme A/AS LEVEL EXAMINATIONS – JUNE 2003 Syllabus 9700 Paper 1 Question Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Key D A C C A C D A B A B C B C D A D A C C Question Number 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Key D B B A C C B B C D A C C D B B D B B C
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arrival of an action potential normally causes the release of neurotransmitters from the presynaptic neuron. The action potential travels down to the axon terminal of the presynaptic neuron. Each axon terminal becomes swollen forming a presynaptic knob. There is a depolarisation of the presynaptic membrane resulting from the action potential. This depolarisation causes an increase in the permeability to sodium and calcium ions. The presynaptic knob is then filled with membrane-bound vesicles; each
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Gabriela Rios-Martinez March 1‚ 2014 BIO 141 Exam 1 Study Questions Chapter 1: Biology and the Tree of Life (#1 – 4) 1. What is the difference between a hypothesis and a scientific Theory? Between a hypothesis and a prediction? What kinds of hypotheses are useful for scientific investigations that try to explain the natural world‚ and which are not? Give one or more examples of hypotheses that are and are not scientifically useful. (a.) A scientific theory has two components; a pattern
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maintains the cell membrane. The main components of the cell include the cell membrane‚ cytoplasm‚ the nucleus‚ nucleolus‚ nuclear membrane‚ endoplasmic reticulum (smooth ER and rough ER)‚ mitochondria‚ Golgi apparatus‚ lysosomes‚ ribosomes and vacuoles. a) The cell membrane – The cell membrane otherwise known as the plasma membrane is located on the surface of a typical animal cell. The cell membrane is made up of a phospholipid bilayer and is a selectively permeable membrane that allows substances
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is an electrical insulation on the axon that increases the speed at which action potential travels
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a partially permeable membrane from a region of high concentration to a region of low concentration‚ creating an equal amount of molecules from both regions on each side of the membrane. This process is the result of a downhill energy system known as water potential. Water potential is the potential energy of water (per unit volume) that allows it to move from one area to another by osmosis. This system causes the water to freely move from an area of higher water potential (energy) to an area of
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