19/9/2024 Part 1 Movement in and out of cell Class work: 1. Define the term diffusion 2. Factors affecting rate of diffusion 3. Define osmosis 4. Describe shape of animal cells in different water potentials 5. Explain shape of animal cells in different water potentials 6. Describe shape of plant cells in different water potentials 7. Explain shape of plant cells in different water potentials Movement in and out of the cell Cell membrane 1. Made from fats and proteins 2.Its a partially permeable membrane 3.It controls the movement of substances ina nd out of the cell Passive Br Movement of molecules across the membrane can either ber Doesn’t need energy Glucose Diffusion. Movement of molecules from area of high Blood : due to random movement of molecules Active Diffusion of water molecules from area of high water potential to area of low water potential ( down water potential gradient ) through a partially permeable membrane through protein With or without a membrane 1. 6’01 Oxygen Osmosis concentration to area of lower concentration Factors affecting diffusion Break Steeper Less steep channels Surface area ..larger the Surface area …the more molecules that can diffuse at the same time 2. Thickness of the membrane …the thinner ..the shorter the diffusion distance Describe Animal cell ( swell and 3. Temperature ..increase kinetic energy of molecules ..so molecules move faster . burst / normal shape / 4. Size of molecules Cell membrane can only pass small molecules Such as CO2, oxygen, glucose , amino acids Plant cell ( turgid / keep Large molecules cant pass through membrane Starch , protein 5. Concentration gradient …difference between high and low concentration shrink ) its normal shape / flaccid) & - M 4:07 - Fat & & O - 0 X X * X -Y - X 8 I - + ↑ t X Y C I f O ↑ ↑ O + 8 & & % - - Y X - -o . Protein X- = - - & M / X - X = - - & & pat O - % · X X / Nat - = ~ Y - - Fat & Protein & Partially permeable membrane X patc ch = ~ t ↑ + Y ↑ I ↑ O + 1 X -4 - Y C + ** C f O t I & Y · N X - 8 . j . Describe and explain the changes taking place in a cell : Animal cell Describe Increase in size Swell and then burst Definition + direction Explain Water moves by osmosis From higher water potential outside the cell to lower water potential inside the cell Through a partially permeable membrane Distilled water ( pure water with zero solute) Through protein pores / channels 0.05mol / dm3 No change in shape 0.05mol / dm3 -Equilibrium -Water potential inside the cell is equal the water potential outside the cell -So no net movement of water molecules 0.01 mol / dm3 * 0.5mol / dm3 Cell shrink Water moves by osmosis From higher water potential inside the cell to lower water potential outside the cell Through a partially permeable membrane Through protein pores / channels Don’t burst because they have cellulose cell wall ..with high tensile strength and unstretchable Describe Vacuole swells , press on the cytoplasm which in turn Explain Keep its normal shape press on cell wall ..the -Equilibrium whole cell becomes turgid Water moves by osmosis inside the cell is From higher water potential outside the cell to lower water potential inside the cell Through a partially permeable membrane Through protein pores / channels -Water potential equal the water potential outside the cell -So no net movement of water molecules by Vacuole shrinks, cytoplasm shrinks as well The whole cell becomes flaccid Water moves by osmosis From higher water potential inside the cell to lower water potential outside the cell Through a partially permeable membrane Through protein pores / channels Plant cell if it keeps losing water it become plasmolysed Describe ( plasmolysis ) Cytoplasm , and vacuole keep shrinking Cell membrane become detached from cell wall Explain Definition + direction ( out of cell) Water moves by osmosis From higher water potential inside the cell to lower water potential outside the cell Through a partially permeable membrane Through protein pores / channels Direct questions of osmosis Definition + direction When to know that i should use osmosis in my answer A) you will find specific key words in the question Answer using the term water potential Explain the change in mass / length / volume …. B) graph showing percentage change in length / mass Cell membrane made from proteins and fats Protein at high temperature ..denature Boiling plant ….cell membrane damaged …protein inside the membrane denature …no osmosis Percentage change ful Gain mass water in O 24681012 we Salt / solute concentration Lost mass..water out 22/9/2024 Part 2 Active transport Recap Solve Carrier protein For active transport Change its shape using energy Protein pore / protein channel For osmosis Doesn’t change its shape Active transport Movement of molecules from area of lower concentration to area of higher concentration / against the concentration gradient using energy respiration through Carrier proteins . · Against the gradient ( difference ) Through carrier protein Using energy Why do active transport needs energy ? High 1. Against the gradient Passive movement with no energy needed • Down the concentration gradient • Doesn’t need a membrane • Example : oxygen, carbon dioxide , urea , glucose 2. To move molecules against their concentration gradient ( low to high ) Active transport Diffusion • Low To change the shape of the carrier protein • active movement of molecules using energy • Against the concentration gradient • Needs a membrane to have carrier protein • • mineral ions in soil …absorbed by root hair cells by active Example : glucose , minerals transport • Glucose in our body absorbed Check list 1. Definition of diffusion Movement of molecules from area of high concentration to are of lower concentration / down the concentration gradient , due to random movement of molecules Example ..gases 2. Factors affecting diffusion : A) temperature ……as it increases the kinetic energy B) surface area …so more molecules can diffuse at the same time so faster diffusion C) thickness of membrane : the thinner the membrane , the shorter the diffusion distance D) size of molecules : Large such as starch and proteins ,, can’t pass through the membrane Small molecules such as glucose and amino acids can pass through membrane E) steepness of the concentration gradient ..the steeper the gradient , the higher the rate of diffusion 3. Definition of osmosis Movement of water molecules from area of higher water potential to area of lower water potential through a partially permeable membrane through protein channels / pores . 4. Describe shape of cells Animal ….swells and burst , keep its normal shape , shrink Plant cell ….turgid , keep its normal shape , flaccid / plasmolysed Explain ….defintion + direction 5. Definition of active transport Movement of molecules from area of lower concentration to area of higher concentration Against the concentration gradient Using energy from respiration Through carrier proteins 6. Explain why active transport needs energy ? To change the shape of the carrier protein To move the molecules against their concentration gradient How to solve 1. Diffusion ,,,,,,,,,gases / he didnt mention a change in mass / volume High to low ….living or non living cell 2. Osmosis A) explain using the term water potential B) change in volume / mass / length C) graph Needs a membrane ( living cell + visiking tubing with membrane ) 3. Active transport Low to high Glucose / ions Living cell …as it needs energy 4. Indirect questions of osmosis In case you have cells all increasing in size yet they are placed in different salt concentrations So all water enter by osmosis From higher to lower potential More water in s Less water in s .... - escita water sai Least water in 50gil ...... Salt concentration increase Water potential decrease Water potential gradient ( difference ) decrease So less water enter into cell by osmosis So less increase in size Salt ~ a Water in As the salt concentration in the salt solutions increase The water potential of the solutions decrease So water potential gradient decrease So less water enter the cells by osmosis Through partially permeable membrane Down water potential gradient So less increase in mass Water out As the salt concentration increase from 04 to 1.2 The water potential of the solution decrease So water potential in potato cells is higher So water potential gradient is steeper / greater / increase So potato cells lose more water by osmosis Down water potential gradient Through a partially permeable membrane So more decrease in mass Explain the difference in mass of potato at 0.2 mol / dm3 with potato at 0.0 mol / dm3 Difference +ve Potato in solution with concentration 0.2 mol / dm3 shows a less increase in mass Explain Both potato cells Water moves into cells by osmosis From high water potential to low water potential Through a partially permeable membrane 0.2 mol / dm3 has higher salt concentration So water potential decrease So water potential gradient decrease So less water enter the potato cells So less increase in mass Explain the difference in mass of potato at 1.0 mol / dm3 with potato at 0.6 mol / dm3 Difference _ ve Potato in solution with concentration 1.0 mol / dm3 shows a greater decrease in mass Explain Both potatoes Water moves out of cells by osmosis From high water potential to low water potential Through a partially permeable membrane 1.0 mol / dm3 has a higher salt concentration So lower water potential / water potential decrease So water potential gradient increase So more water leaves the potato cells So more decrease in mass .... S on & A & J 28 M 128 28 - & o 100 O.0 salt 0.2 salt go Water in +VE M & Se O.3 salt A jo · Salt Water potential ↓ Water potential gradinet As the salt concentration increase The water potential decrease The water potential gradient decrease So less water in , so less increase in mass 100 yo to 100 go 60 go : Water out 18 30 ~ · = O,6 ↑ S 0.8 - 1.0 & -ve - - - As the salt concentration increase The water potential decrease The water potential gradient increase So more water leaves the cell , so more decrease in mass Salt Water potential Water potential gradinet Olevel Biology Biology 0610 Page 3 May/june 2004 Adaptation 1. Movement in&out of cells Syllabus-0610 Paper 03 ab r 1 Paper 3 Cytoplasmic extension to provide a larger surface area for maximum absorption of water and minerals thus allowing more molecules to diffuse at the same time . lG 2. Thin cell wall : shorter diffusion distance 3. large number of Mitochondria site of aerobic respiration to release energy for active uptake of mineral ions 4. Concentrated sap vacuole to allow water absorption by osmosis .N iha - Direct Large number of mitochondria to release energy from respiration for active uptake of mineral ions Thin cell wall for shorter diffusion Dr Direct Movement of molecules from low concentration to higher concentration using energy from respiration through carrier protein Uptake of minerals is by active transport Which needs energy from respiration Dr.Nihal Gabr 71 76 Dr. Nihal Gabr Olevel Biology Wo 100% water Salt concentration increase Water potential decrease Water potential gradient ( difference ) decrease So less water enter into cell by osmosis Highest water lG ab r 1. So less increase in size potential 2. Least solute concentration W 96 salt 88% water Least Water .N iha 01093850599 go Highest Results As the concentration of sea water increase , the rate of water excreted decrease Dr Explain As the salt concentration increase Water potential decrease Water potential gradient decrease So less water enter by osmosis So less excess water 88 Dr. Nihal Gabr Olevel Biology Cell wall helps the cell keeps its shape / unstretchable Thinking Keep cell turgid Resist increase in pressure lG ab r Prevent the cell from bursting -cewa - - - - ... - : ..... --- Net ..water in . - Dr --- - - - .N :.. iha ... ~ a Focal Salt concentration decrease Water potential increase Water potential gradient increase So more water will enter by osmosis 89 Dr. Nihal Gabr Olevel Biology 16 Paper 41 May/June 23 lG ab r 01093850599 .N Water out iha Water in Final - starting Dr Starting -13.28 1.11- 1.28 X 100 1.28 100 -13.28 98 Dr. Nihal Gabr Olevel Biology Direct The potato showed a greater decrease in mass when placed in Difference Explain solution of 0.8 mol /dm3 Water moves out of the potato cells by osmosis From high water potential to lower water potential lG ab r At 0.8 mol /dm3 has higher salt concentration than 0.6 So has lower water potential So higher water potential gradient So more water loss so greater decrease in mass M - . - · · : · it ... quadet · iha High water potential solution Potato cell will get larger Cell becomes turgid .N Vacuole and cytoplasm swells Active transport Passive movement Active movement needing no energy needs energy Dr Osmosis Direct Molecules move against Down water potential concentration gradient gradient Through protein channels / pores Through protein carriers 99 Dr. Nihal Gabr
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