semi-permeable membrane and presence of charged particles in solution (ions)‚ enables the cell to have control of an electric potential. The cell The concentrations of Na+ and K+ ions upon either side of a cell’s membrane are not equal. In order for the equilibrium to be restored‚ sodium will attempt to enter the cell‚ whilst potassium will exit the cell. It is this movement that is harnessed to generate electricity. However‚ these ions cannot interact directly with the lipid bi-layer membrane and cross
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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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relates to this course by the basic information I learned about the plasma membrane known as cell membranes. Cell membranes are lipid bilayers that consist mainly of phospholipids. However‚ when it comes to cancer cell membranes they tend to have more anionic lipids than normal cells. Our course text in Chapter 3 talks about the “Cell Structure” and gives us the break down on “What Exactly is a cell? The Structure of Cell Membranes‚ Introduction of Prokaryotic Cells‚ etc.” This article does not provide
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1: Cell Transport Mechanisms and Permeability: Activity 2: Simulated Facilitated Diffusion Lab Report Pre-lab Quiz Results You scored 50% by answering 2 out of 4 questions correctly. 1. Molecules need a carrier protein to help them move across a membrane because Your answer : a. they are not lipid soluble. Correct answer: d. they are lipid insoluble or they are too large. 2. Which of the following is true of facilitated diffusion? You correctly answered: c. Movement is passive and down a concentration
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April 27‚ 2012 Background All living organisms (plants‚ animals‚ and bacteria) are made up of cells. Any cell consists of many parts but the parts that play the key roles are the nucleus‚ cell membrane‚ and cytoplasm. The nucleus is like the “brain” of the cell (that also contains DNA). The cell membrane is like a wall that guards the cell. And the cytoplasm is a jelly-like substance which contains other smaller organelles like mitochondria that generates energy for the cell. Purpose/Investigation
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Title: The effect of temperature on beet cell membranes. Introduction: 1. Eukaryotic cells are much more intricate than prokaryotic cells. The first thing observed is the assortment of structures in the cytoplasm. The fluid filled region between the nucleus and the plasma membrane. These structures along with the nucleus are the organelles‚ each having a specific function in the cell. The organelles are by membranes divided in proficient sections .The plant cell is made up of a rigid thick wall
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aquaporins in cell membranes from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration). This process is called osmosis. It requires no cellular energy to be used‚ and occurs due to the random‚ continuous motion of all molecules. If a cell is placed in an environment in which the concentration of water is less than in the cell (hypertonic)‚ water will flow from the cytoplasm and/or water vacuole through the membrane into the environment
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beetroot‚ the more pigments well leak out from the cell membrane‚ hence the absorbance would increase. My hypothesis was concluded by the facts that beetroot contains red pigments called betalians which are located in the cell vacuole. Normally the pigments cannot leak out; however cooking the beetroot allows the movement. This is because the cell membrane selectively controls the movement of substances into and out of the cell. The membrane is made of 40% lipids‚ 0-10% carbohydrate and 50- 60%
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DNA Extraction from Fruit 1. What was the purpose of adding liquid soap and salt in step #1 and how does NaCl contribute to maximum DNA extraction. The purpose of using soap was to destroy the membranes inside a kiwi cell. Soap helped with that because it dissolves the membranes easily. Salt or NaCl was used to remove proteins and carbohydrates. NaCl caused the proteins and carbohydrates to precipitate. 2. Why was it necessary to “mush” the kiwi by hand? If the step was omitted‚ what
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shields the negative phosphate ends of DNA‚ which allows these ends to come closer so that the DNA can precipitate out of a cold alcohol solution. The homogenizing solution causes the cell membrane to break down by dissolving the lipids and proteins of the cell‚ which disturbs the bonds that hold the cell membrane together. The homogenizing solution then forms complexes with the lipids and proteins causing them to precipitate out of the solution. After the isolation of the DNA from the solution‚ different
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