Concept explainers
(a)
To determine: The flux of molecules when the size of molecule increases.
Introduction: Flux is defined as the rate of diffusion per unit surface area of a membrane. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration.
(b)
To determine: The flux when there is an increase in the concentration gradient.
Introduction: Concentration gradient is described as the difference in the concentration of a molecule or ion between two regions. It is also known as chemical gradient.
(c)
To determine: The flux when there is a decrease in the surface area of a membrane.
Introduction: The flux of a molecule across the membrane is described as the rate of diffusion rate per unit surface area of membrane.
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Human Physiology: An Integrated Approach (8th Edition)
- A red blood cell with an intracellular fluid (ICF) concentration of 280 mmol/L, is placed into an environment were the concentration of the extracellular fluid (ECF) is 305 mmol/L. As a result, water will move across the cell/plasma membrane. a) Name the process by which water moves b) Describe the overall direction of movement of the water. Answer choices: (i) From outside the cell to inside the cell (ii) From inside the cell to outside the cell, or (iii) Equally, into and out of the cell iii Explain your reasoning for your answer to part (c). 1In your answer you must describe the environment on both sides of the membrane, and use 3 of the following 4 terms correctly; hypertonic, hypotonic, lower solute concentration, higher solute concentrationn (2pts -Correct use of biological terminology, and correct spelling is essential. Edit View Insert Format Tools Table 12pt v Paragraph BIUA ...arrow_forwardDistinguish between simple diffusion (SD), facilitated diffusion (FD), and active transport (AT) across a membrane for the following questions. (a) Which processes are energy dependent? (b) Which processes need some kind of carrier protein(s)? (c) Which processes can be saturated by substrate? (d) Which processes can establish a concentration gradient? (e) How much energy does it take to transport an uncharged substrate in, if its starting inside concentration is 10-fold greater than outside?arrow_forwardThe distinctive properties of facilitated diffusion are: (a) Increase the speed of diffusion of substances (b) Transport of substances towards increasing concentration Additional energy consumption for transport (c) Transfer of substance involving carriers (d) Integration flux of substance and ion transport (e)arrow_forward
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- Whether in a gas, a liquid, or a semisolid, diffusion always occurs a). at the same rate. b). from high to low solute concentration. c). faster at lower temperaturesd). from low to high solute concentration.arrow_forwardWhich statements are consistent with the known facts about membrane transport? (a) Active transport moves a substance from a region in which its concentration is lower to one in which its concentration is higher. (b) Transport does not involve any pores or channels in membranes. (c) Transport proteins may be involved in bringing substances into cells.arrow_forwardAs molecular weight increases.a). the rate of diffusion remain unchanged.b). the rate of diffusion decreases.c). the rate of diffusion increases.d). the rate of diffusion stops.arrow_forward
- Which of the following statements is correct about diffusion? a) It is an active process in which molecules move from a region of lower concentration to one of higher concentration. It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration. c) it requires integral proteins d) It is a rapid processarrow_forwardWhich statements are consistent with the fluid-mosaic model of membranes? (a) All membrane proteins are bound to the interior of the membrane. (b) Both proteins and lipids undergo transverse (flip-flop) diffusion from the inside to the outside of the membrane. (c) Some proteins and lipids undergo lateral diffusion along the inner or outer surface of the membrane. (d) Carbohydrates are covalently bonded to the outside of the membrane. (e) The term mosaic refers to the arrangement of the lipids alone.arrow_forwardThe intracellular salt content of a red blood cell is about 150 mM. The cell is put in a 500 mM salt beaker. (a) Describe what will happen to the cell in terms of osmosis if the cell membrane is permeable to water but not to ions. (b) Which direction would solutes diff use if the membrane was permeable to ions: into or out of the cell?arrow_forward
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