Bio PDF - Microscope Images & Cell Structure

Chapter 2 microscope image light microscope : coloured image only nucleus, chloroplast(chlorophyll), vacuole, cell wall can be seen 1600x Q) discuss briefly the impact of the advance...

Chapter 2 microscope image light microscope : coloured image only nucleus, chloroplast(chlorophyll), vacuole, cell wall can be seen 1600x Q) discuss briefly the impact of the advance in microscopy of the study of cells Electron microscope produces image with higher magnification and resolutions. This enable scientist to discover the structure of cell organelles. Scanning electron microscope: 3D external structure 200000x Transmission electron microscope : 2D internal structure 1500000x operating the light microscope add iodine solution to stain the Inverted image specimen → to make the cell structure more distinct/ visible To observe more cells within the field of view → reduce the distance between the slide and the objective Raise the stage/lower the body tube by turning the course at Jasmine until the object is at the position closest to the slide Step for focusing from low power to high power : 1.Focus with a lower power objective 2. The field with the low power objective by turning the course adjustment knob/fine adjustment knob 3. Adjust the position of the slideuntil it is located in the centre of the field 4. Focus with a high-power objective by turning the nosepiece 6. Turn the fine adjustment to get a sharp focus 5.Adjust the source to brighten the view if necessary ( diaphragm/ condenser) (6-7) keep watching the stage from the side. raise the stage by turning the course adjustment up until the object nearly touches the slide look through the focused image by turning the fine adjustment knob. Adjust the source to brighten the view if necessary Blurred to sharp →rotate the fine adjustment knob to get a  sharper focus cell structure label questions : small particles → ribosome Endoplasmic reticulum (x rought / smooth) Finding out the organelles by the type of cell: 1.X is organelle name (1) 2.What is the cell responsible for/the function of the cell.(1) 3.abundant of organelles was found for function of the organelles (1) 4.function of other type of cells, so the don’t have much organelle X (1) ＊＊show comparison Finding out the type of cell by number of organelles 1.Z is most likely to be a xxxx cell (1) 2.It has large amount of organelle to function (1) Similarities and differences Both of them xxxxxx Z cell has vvvvv but S cell does not abundance of organelles in different type of cells eukaryotic and prokaryotic Chapter 3 membrane structure and the permeability whole cell membrane : Q1) state the components: Phospholipid can move laterally Q2) to describe the cell membrane Phospholipid → arrange into a bilayer structure. The hydrophobic tails point inwards. The hydrophilic head points outwards to the bathroom solution and point inward to the cytoplasm Protein → among the phospholipid bilayer Q3) explain the arrangement of phospholipid The hydrophilic tails point inwards as they are repelled by the aqueous solution The hydrophilic head point outwards towards bathing solution as it dissolves with the aqueous solution inside and outside of the cell Q4) explain how protein and phospholipid affect the permeability of the cell membrane to different substances Phospholipid bilayer allows fat soluble molecules/hydrophobic/nonpolar molecules to diffuse more readily across membranes(1) Samall charged molecules can dissolve in your hydrophobic zone and diffuse freely through the phospholipid layer.(1) The hydrophobic in the stone forms a barrier to those molecules which are polar/hydrophilic/ions(1) Chan protein for open pores for diffusion of ions and polar substances(1) Carrier proteins find with specific molecules and bring them to the opposite side of the membrane(1) Carrier protein can facilitate diffusion of some molecules e.g. glucose (1) Carrier protein allows active transport of molecules(1) ATPase catalyses the hydrolysis of ATP to liberate energy for active transport (1) Phospholipid and the permeability of the membrane : Q)The phospholipid arranges tail to tail to form a bilayer (1) It allows lipid soluble/ non-polar substances to go through as they dissolve in the hydrophobic zone of the bilayer. (1) The hydrophobic tails of the phospholipid molecules point inwards (1) Forming a inner hydrophobic zone (1) Which acts as a barrier, and the membrane and permeable to charge molecules (1) Protein :  **transport by carrier/channel protein is undirectional permeability and property of the cell property: membrane 1. Flexible → the phospholipid and protein molecules can move about slightly → the cell membrane can break and fuse to change shape during cell division and growth 2. The cell membrane is differentially permeable →the core the of the membrane is water+hating Describe and explain how oxygen and sodium ions are transported through the artificial or cell membrane Q1) Oxygen molecules are nonpolar and small. To solve and hydrophobic sound in the phospholipid the bilayer. Pass through both  membranes at the same rate. Sodium irons are charged and they are repelled by the bilayer and cell membrane. They can be transported by channel or carrier proteins. As these proteins are absent and artificial membrane, it cannot move across the membrane Movement of substances across the membrane: Factors that affect the permeability of the cell membrane 1. Temperature 2. Organic solvents e.g. ethanol and alcohol →phospholipid of the membrane dissolve in organic solvents. The cell membrane and vacuole would be damage →（release pigmanet and colour intensity ) Fluid mosaic model Q1)draw the fluid mosaic model : Q2)Justify/ explain the model Fluid → the phospholipid can move laterally Mosaic → protein interpose on the surface of the membrane in a mosaic pattern in an  asymmetrical manner diffusion definition:net movement of particles down the concentration gradient Evenly distributed/reached equilibrium →no net movement but still move randomly Exchange of materials →obtain useful and remove waste (gas exchange ) Absorption of nutrition osmosis water potential= solute concentration+ hydrostatic pressure →it is the tendancy for water molecules to move from one place to another →more solute, stronger attraction between solute and water molecules, decreases water potential Molecules are too large to pass through It requires a differentially permeable membrane Q1)State the change in water level in the dialysis tubing and explain Water level of dialysis tubing rises. The water potential of the distilled water is higher than that of 20% sucrose solution. There is a net movement of water molecules from water to sucrose solution a differentially permeable membrane by osmosis.  Q2)Why did the water level stop moving As water enters the dialysis tubing, this increases the water level and it creates hydrostatic pressure which stops the movement of water molecules from further entering the tube. the water potential of warer inside and outside tube are the same/They have reached equilibrium There will not be any more net movement of water molecules. So the water stops moving. Ways the increase the rate of rise of water level in the capillary tube 1. Raise the water level to 30 C 2. Use a capillary tube with a smaller internal diameter 3. Use a longer piece of dialysis tubing →increase surface area 4. What can be deduced from the result 1. the water potential outside the dialysis tuning is higher than that of inside the tube 2. Solute if the solution in the dialysis tubing cannot pass through the diaysis tuning Conclusions that we can draw from the result 1. There is a net movement of water into the dialysis tubing Q3)describe and explain 1. It starts rising at ＿ 2. The slope is getting less steep 3. It stops rising in point ＿ （describe) As small water molecules enter 20% sucrose solution →the water potential gradient between sucrose solution and distilled water decreases →the slope decreases over time →rate of osmosis decreases (Explain ) Q4) to deduce the value of water potential of (b) with reasons As the water level stops increasing → water potential gradient doesn’t exist between the bathing solution and the 10% sucrose solution → as the water potential of distilled water is zero, the water potential in the dialysis to tubing is 0 as well Q5) explain why water level stops further moving after it reached equilibrium state To increase water level in the capillary tubes create a hydrostatic pressure which prevents further net movement of water molecules into the dialysis tubing  Q6)state the difference of the two curves 30% has a steeper slope and its curve is higher Q7)state the difference between two slopes and explain The slope is steeper for 40° C When temperature increases, it increases the kinetic energy of water molecules. Water molecules will move faster. This will increase the rate of osmosis. It takes less time to reach equilibrium potato reason :The skin of the potato acts asa barrier to water/the skin after potato is in permeable to water. Therefore, no water movement will occur. State the difference and explain : The slope is steeper in (3) than (2) The rate of osmosis is faster because there is a larger surface area for osmosis to take place Q8)Explain the change in (a) As the potato is boiled, the cell membrame becomes fully permeable. There is a net movement of water molecules diffuse into 10% sucrose solution down the water potential gradient. While the net movement of sucrose diffuse out to distilled water However sucrose has a larger size so the rate of sucrose diffusing into the 10% is slower than the rate of water diffusing into the sucrose solution So in (a) the water level rises Q9)Explain the change in (b) After some time, the sucrose molecules have diffused out of the 10% sucrose solution and the concentration of sucrose in the potato cavity and outside Q10) how can the student be sure that tge RBC in the tube has reached equilibrium with the surrounding solution at the time when he made the observations ? Oberve the __ again some time The __should remain the same of it has reached equilibrium the the previous observation Explain :  **flaccid →failed to press against each other →soft 1. Which one has a higher water potential 2. Hypo/iso/hyper 3. There is a net movement of water molecules from ＿＿to ＿＿ through a differentially permeable membrane by osmosis 4. Change/ state of the cells **bursting of RBC leading to the leak of hemoglobin (haemolysis) a read solution ,at be resulted Absorption of water in human intestines and plant roots from soil Preservation of food →concentrated salt/ sugar →water is drawn out from microorganisms which growth may cause food decay →they will die or stop growing due to lack water active transport  Requires energy from respiration of cells →high rate of at =high rate of respiration =a lot of mitochondria Decrease the rate = crease the rate of respiration →low tem. low oxygen concentration, cyanide Function Obtain additional useful materials which are already inn high concentration in cells Absorption in nutrition (glu+amino) Absorption of minerals from soil into plant roots phagocytosis →It is the uptake of large particles into cells by packaging the particles into vacuoles form from the cell membrane **energy is needs to change the shape of the cell membrane Important of unicellular organisms’ nutrition (Amoeba) WBC engulf harmful substances → important for body defence against disease Chapter4 anabolic and catabolic graph experiment graphs volume of gas collected with time ** Total amount of product form depends on concentration and volume of substrate/enzyme. As these are the controlled variables Q1a)Describe 1.from time 0-Xs, the volume is increasing 2.the slope becomes less steep 3.from the time X onward, the volume stops increasing Q1b)explanation As the (enzyme) breaks down the (substrate), forming (product). So the volume of (product) increases. Rate of (product) released decreases as the amount of product formed per second is decreasing. So the collision between enzyme and substrate is decreasing.The formation of enzyme substrate complex decreases. All substrate are used up so no more formation of products. Q2a) describe 40 C It has a steeper slope Q2b)explain 40 C  As the temperature increases, the kinetic energy of substrate and enzyme increases. Collision between them increases. Therefore there is the increased formation of enzyme substrate complex. The rate of product formed increases. it reaches.(amount of product) at a shorter time. Factors that affect the enzyme activity : 1. Temperature 2. pH 3. Cyanide (inhibitors ) 4. Heavy metals e.g. mercuric ion, lead(ll) ions, copper(ll)ions experiment the action of enzyme : Boil the enzyme IV DV The presence of enzyme: CV Enzyme →water properties 1. they are specific in action →active site with specific shape for certain substrate to fit in →lock-and-key hypothesis  2. Reusable 3. →needed in relatively small amount 4. Protein in nature →easily affected by pH and tem. 5. They are biological catalysts daily applications (not important ) Food making Cheese making Proteases(cows' stomachs)coagulate milk to produce cheese Fruit juice extraction Pectinase can help break down pectin in plant cell walls and in the juice →increase the yield of juice extracted+break make the juice looks clear. Liquid-centred chocolate production Invertase added into solid sugar fillings →helps break down the sugars into more soluble forms → solid sugar fillings to gradually turn into liquid upon storage. Cooking papain(a protease extracted from papayas ) → helps break down the proteins in meat so that the meat becomes softer. Environmental protection Detergent ✅ Biological washing powders ( proteases* and lipases) →help break down the insoluble proteins and lipids in stains into soluble products then it can be removed by water easily Cosmetic cleansers ( papain ) →help break down dead cells in the skin. →make skin softer and smoother. Textiles Stonewashed jeans production →cellulase helps break down the cellulose fibres in the jeans Medicine Lysozyme( drug ) to treat some bacterial infections. → help break down the cell wall of certain  bacteria and kill them Chapter 5 food substances formation and fumction food source test Extended/ questions carbohydrates carbohydrates 1. Glucose →glucose test paper 2. Reducing sugar → Benedict’s test Note:monosaccharides are small molecules and are soluble in water Glucose : main energy source →directly broken down to release energy during respiration →an immediate energy source for body activities 3. Starch → iodine test Polysaccharides: Not sweet and soluble Glycogen (form from glucose ) →energy reserve in animal →broken down into glucose to release energy when needed →abundant in liver and muscles Starch (form from glucose ) →energy reserve in plants / main energy source for body activities →abundant in rice,wheat,potatoes,taros Cellulose (form from glucose ) → form cell wall and a source of dietary fibre Lipid grease spot test (positive result ) Extended Put a drop of the food sample onto a piece of Saturated fats and unsaturated fats filter paper and let it dry The fatty acids in lipids can be saturated or → A translucent* spot will remain on the filter unsaturated paper Lipids that are rich in saturated fatty acids are →immerse the filter paper into an organic called saturated fats*. They are often solid at solvent and take it out. room temperature. Taking in too much saturated →The translucent spot will disappear if it is fats may lead to cardiovascular diseases* like formed by lipids. heart disease and stroke*. Phospholipid to form cell membrane Trans fats 7. Lipid stored in adipose tissue can act as Trans fats* are produced when plant oils are energy reserve solidified in an industrial process, or when they 8. Subcutaneous fat can act as shock are exposed to very high temperatures during absorber to protect internal organs ans cooking (e.g. deep-frying). Trans fats are found heat insulator in cakes, bread and deep-fried foods. They are 9. Each gram of lipid provide twice amount also linked to cardiovascular diseases. if energy tyam carbohydrates 1. Phospholipid to form cell membrane 10. Produce lipid hormones 2. Lipid stored in adipose tissue can act as 11. Involved in the absorption, transport and energy reserve storage of lipid-soluble 3. Subcutaneous fat can act as shock absorber to protect internal organs ans heat insulator 4. Each gram of lipid provide twice amount if energy tyam carbohydrates 5. Produce lipid hormones 6. Involved in the absorption, transport and storage of lipid-soluble vitamins Protein foods like meat, fish, eggs, beans, milk and dairy products Proteins in our body ( 20 amino acid) amino acids +dipeptide → polypeptide Twelve amino acids (non-essential ) →produced in our body The remaining amino acids (essential) →obtained from our diet polypeptide coils and folds in a specific way →form 3-dimensional structure →the H-bond holds the amino acids together in a specific way Vitamin Vitamin A 1. Fish liver oils, liver, eggs, milk and dairy Functions products are rich in vitamin It is needed for the formation of a pigment in 2. carrots, pumpkin, sweet potatoes ano the retina* of our eyes. The pigment is necessary mangoes) contain carotene (orange for vision in dim light. pigment) It is important for keeping the cornea", skin, →converted to vitamin A in our liver. lining of the alimentary canal" and breathing system* healthy Deficiency poor vision in dim light/night blindness* drying up of the cornea and skin easy infection of the lining of the lungs and trachea Vitamin D Function promotes the absorption of calcium and 1. Sunlight phosphate 2. Fatty fish (such smalon and tuna), →essential for keeping bones and teeth strong fish liver osli, liver eggyolk →very important ot children for hardening of bones and development of teeth Deficiency Rickets in children Vitamin C Function growth and repair of connective tissues which 1. Fresh vegetables and fruit :bell peppers, DCPIP solution decolourize help keep body structures in place. broccoli, guavas and kiwi fruits healing wounds. It promotes the absorption of iron from plant foods. helps the immune system work properly to protect the body from diseases. Deficiency(scurvy): Symptoms weak and bleeding gums poor healing of wounds small red spots on the skin joint pain Minerals Calcium Canned sardines, milk,dairy products, tofu and involved in blood clotting, sending messages im some green vegetables the nervous system, muscle contraction component of bonds and teeth Deficiency  Rickets in children → Osteoporosis for elderly → Beef, liver, beans,cabbage, spinach and Iron raisins a component of haemoglobin Deficiency Anaemia →faint easily →not enough o2 to support the brain Dietary fibre and water function : Vegetables, fruits and wholemeal products 1. Add bulk to food to stimulate peristalsis and facilitate digestion 2. Hold water to soften faces Deficiency: Constipation Balanced diet children : Men : Women: Pregnant women : Overweight : Underweight : Chapter 6 Organs Function Questions teeth Alimentary canal