Water potential of potato cells experiment.
Water potential of potato cells Aim: To investigate the effect of varying concentration of a certain sugar solution on the amount of osmotic activity between the solution and a potato chip of a given size. Hypothesis: The potato chips left in dilute solutions will increase in size, while the potato chips left in the concentrated solutions will decrease in size. This is because the water in hypotonic solutions will move into the potatoes (where there is a lower concentration) increasing its mass and vice-versa. Method: Cut 8 peeled potato chips 30mm long. Blot each chip dry and mass accurately to 2 decimal places and then measure elasticity of chips. Then immerse each potato chip in eight different solutions of sucrose: 0.0M, 0.1M ,0.2M, 0.3M, 0.4M, 0.5M, 0.6M, 0.7M Leave the chips for 30mins. After 30mins record the new mass of each chip and change in elasticity Observations: Distilled water:- The potato chip increased in mass. It was also very rigid and hard. 0.1M solution:- The potato chip increased in mass. It was relatively hard and rigid but not as much so as the chip immersed in distilled water. 0.2M solution:- The potato chip decreased slightly in mass. It felt the same as before 0.3M solution:- The potato chip decreased in mass. It was a bit softer than before submersion. 0.6 M solution:- The potato chip decreased mass. It was very soft and
Biology SL Lab Report - Genetically Modified Crops and Health
BIOLOGY SL GENETICALLY MODIFIED CROPS AND HEALTH Tessa Reed 4mm In today's society, the goal of many scientists is to try to figure out as much as possible about genetically modified organisms and their influence on humans, animals and plants. Very often, scientists genetically modify the food humans eat, in order for it to live in a certain area where it usually couldn't, to protect it from diseases or simply for it to taste or look better. A good example for this is the usage of artificial genes on rice plants, which protect it from viruses, increase their grain size or generate flavors and nutrients. As we all know, rice is the most important food for most of the human population. The aim of the upcoming experiment is to test how artificial substances affect the growth and development of rice plants and, later, the effect of their fruit on the many humans that eat them. For my experiment to go through, I will need to travel to India. India is one of the cradles of rice cultivation and, also, the second most populated country in the world. Half of the population is fed by rice daily. Favorable locations for rice cultivation are moist and damp places near rivers. Because of this, the delta of the Cauvery river in south-east India is a good location for planting seedlings of rice plants. The rice in this area is perennial, meaning it lives long and is capable of
Finding the vitamin C content of a lemon
________________ INTRODUCTION In our experiment we tested the amount of vitamin C in a certain amount of lemon juice. We did this with the help of PCPIP which is an indicator that shows the presence if C vitamin. For this we used the mentioned indicator, pipette, three eprouvetes, 0.1% of C vitamin solution and lemon juice. First we had to get the volume of 0.1% vitamin C solution that is needed for our amount of PCPIP (2ml) to decolorize. Then we had to determine the volume of lemon juice that is needed to decolorize the same amount PCPIP. This provided us with the concentration of vitamin C in the lemon juice. RESULTS We got separated into four groups and the results of all of the groups were in the end combined and the average was calculated. Our first result was that the indicator will change the color if we add 0.75 ml of 0.1 % C vitamin solution to it. We know that 100 ml of the solution contains 0.1 g of vitamin C so with that fact we calculated the amount of grams that can be found in 0.75 ml. We calculated this in the following way: This means that we have 0.75 mg of vitamin C in 0.75 ml of solution. It also means that the indicator (2ml) will turn transparent after we add 0.75 mg of vitamin C. After that we added lemon juice to the third flask with the indicator. We continued with the addition until the indicator turned transparent. It first turned
The aim of this lab is to use an artificial partially permeable membrane to replicate osmosis by filling three different bags
Lab Osmosis Introduction Osmosis is the net movement of water molecules through a partially permeable membrane, from their high water concentration to their low, this process occurs in a cell when the concentration of water molecules is higher inside the cell then outside, this means that the solution is hypertonic, which means that the water molecules will move outwards until they achieve equilibrium, but the water can also move inside the cell when the solution is hypotonic which means that there is a lower water concentration inside the cell then outside, so the water molecules will move inside the cell until it reaches equilibrium, when the solutions both inside the cell and outside the cell are of equal concentration the solution is called isotonic. The aim of this lab is to use an artificial partially permeable membrane to replicate osmosis by filling three different bags of this partially permeable membrane (in this case dialysis tubing) with three different concentration of sugar-water solution. Material . 8 pieces of string 2. 4 water soaked dialysis tubing about 15 cm long 3. Graded cylinder or mechanical pipette 4. 1% sucrose solution 5. 25% sucrose solution 6. 50% sucrose solution 7. 1000ml beaker 8. Large bowl 9. Scale (±0.01 g) 0. Timer (±1s) Hypothesis I expect that bag A will lose mass due to the fact that the water concentration outside the
How does the concentration of hydrogen peroxide affect the time (s) it takes the enzyme catalase to decompose it into water and oxygen gas?
Biology Hl-Enzyme Design IA Elena Mastin Wood Research Question: How does the concentration of hydrogen peroxide affect the time (s) it takes the enzyme catalase to decompose it into water and oxygen gas? Variables: Dependent: . Time (in seconds) taken for the decomposition reaction to be complete. . Measured using a stopwatch Independent: . Molar concentration (mol/L) of hydrogen peroxide (H2O2) . Solutions will be increased in concentration from 1 mol/L to 1.25 mol/L, to 1.5 mol/L, to 1.75 mol/L, to 2 mol/L. Controlled: . Mass (in grams) of pureed cow’s liver (catalase) . Each test will use 10 grams of pureed cow’s liver, containing the enzyme catalase. 2. If uncontrolled, the reaction time could be either increased or decreased because of the changed amount of the catalyst, create imprecise data. . Temperature . The lab will be kept at a constant temperature of 20 degrees Celsius. 2. Temperature is a primary factor affecting both enzyme activity and reaction speed. . Volume of hydrogen peroxide . A standard volume of 20mL of hydrogen peroxide will be used in each test, with ample amounts of water to change the concentration. 2. If it was measured using 20mL of the hydrogen peroxide solution, there would be less of the substance at lower concentrations, which would speed the reaction and possibly skew the
Finding the isotonic point for potato tissue
Noémie Pauwels BIOLOGY COURSE WORK Finding the isotonic point for potato tissue . Raw results table Concentration of sucrose solution (M) Mass of potato sticks (g ±0.01g) Before soaking in sucrose solution After soaking in sucrose solution for 30 min. 0.0 2.90 3.05 2.90 3.04 2.86 3.05 2.88 3.01 2.80 2.98 2.87 3.01 0.2 2.96 3.01 2.97 3.03 2.90 3.04 2.91 2.98 2.80 2.86 2.87 2.96 0.4 2.90 2.84 2.87 2.83 2.76 2.73 2.84 2.77 2.83 2.79 2.90 2.81 0.6 2.97 2.81 2.98 2.74 2.99 2.78 2.91 2.80 2.97 2.79 3.00 2.77 0.8 2.81 2.61 2.88 2.63 2.87 2.61 2.90 2.62 2.91 2.64 2.92 2.68 1.0 2.88 2.69 2.88 2.62 2.92 2.64 2.89 2.61 2.90 2.61 2.88 2.62 . Processed results table Concentration of sucrose solution (M) Mass of potato sticks (g ±0.01g) Before soaking in sucrose solution Before soaking in sucrose solution Difference Percentage change in mass of potato sticks (%) Mean percentage change in mass of potato sticks (%) Standard deviation of percentage change in mass of potato sticks (%) 0.0 2.90 3.05 + 0.15 2.90 3.04 + 0.14 2.86 3.05 + 0.19 2.88 3.01 + 0.13 2.80 2.98 + 0.18 2.87 3.01 + 0.14 + 5.17 + 4.83 + 6.64 + 4.51 + 6.43 + 4.88 + 5.41 0.82 0.2 2.96 3.01 + 0.05 2.97 3.03 + 0.06 2.90 3.04 + 0.14 2.91 2.98 + 0.07 2.80 2.86 + 0.06 2.87
Beet Lab. Aim: To determine the effects of temperature on the permeability of the beetroot cell membrane.
Biology HL Lab Report Beet Lab Data Collection, Processing, Presentation Conclusion & Evaluation -Rashika Singh IB Yr 1 Aim: To determine the effects of temperature on the permeability of the beetroot cell membrane. Research Question: To investigate how different temperatures affect the beetroot pigment and finding out the absorbance and transmittance % using a visible spectrophotometer. Background Information: Beetroots contain betalains which are the red pigments present in the cell vacuole. Betalains are soluble in water and they contain nitrogen. Betalains extracted from beetroot is commonly used as food dye because it is not known to cause any allergic reactions. Cell membrane is the barrier that separates the inner environment of the cell from the outer environment. The membrane is selectively permeable. The cell membrane is made up of mainly lipids, carbohydrates and proteins. The lipids are the phospholipid bilayer which consists of a hydrophilic polar head and a hydrophobic tail. Among the proteins present in the cell membranes are integral proteins and peripheral proteins. {1} Lipids increase in fluidity as temperature increases. Once denatured, proteins start to unravel and are unable to carry out their function. Diffusion is the movement of molecules from high concentration to a low concentration down a concentration gradient. Facilitated diffusion
Talking Parrot - review of "Alex and Me" by Irene Pepperberg
Title: Alex and Me Author: Irene Pepperberg Josh Keller This relatively short recount of Irene Pepperberg’s experiment with Alex is a very intriguing book. The truth behind it and the idea of a thirty year experiment between man and beast is awe-inspiring. The short 226 page story is written by Irene herself, but recounts the story very well in very few words. The story of Alex is told starting with his end. After Alex, an African Gray, passed away at an early age for his species of bird at 31, Irene Pepperberg was in a state of grieving. She had worked with Alex for over three decades. Although she maintained a scientific relationship, an objective approach, she still became emotionally attached to Alex without noticing it. Alex left with his final words being “You be good. I love you.” Pepperberg compared losing Alex to be the same as losing her baby several years earlier. People all around the world who were touched by Alex wrote in to Irene sending their condolences. Irene Pepperberg began her interest in birds when she received a baby parakeet for her 5th birthday. She can’t remember its name and it never talked, but it played with her and flitted around on her shoulder wherever she was in their house. She grew older and kept getting more birds, with her first bird to talk being Charlie Bird number one. The summer before her senior year, she was
The Effect of Indicators on the presence of Macromolecules in a McMush slurry
The Effect of Indicators on the presence of Macromolecules in a “McMush” slurry 0 October, 2012 Rani Bhangu . The Effect of Indicators on the presence of macromolecules in a McMush 2. Design . Are carbohydrates, lipids, and proteins present in the McMush? 2. Introduction “The organic compounds found in living organisms are lipids, carbohydrates, proteins, and nucleic acids. These macromolecules are large carbon-based structures. Common foods, which often consist of plant material or substances derived from animals, are combinations of these organic compounds. The macromolecules are assembled by joining several smaller units, called monomers, together through a chemical reaction called dehydration synthesis or condensation. The resulting polymer can be disassembled/ broken down into monomers through the complimentary process called hydrolysis” (Lazar, 1). Background Carbohydrates are made of carbon, hydrogen, and oxygen atoms (CHO). In the carbohydrate there are two hydrogen atoms for every one oxygen atom present. The monomers for carbohydrates are referred to as monosaccharides. When many monosaccharides are chained together the resulting molecule is called a polysaccharide. Carbohydrates are used by living organisms as an important source of energy. Examples of carbohydrates include glucose, fructose, sucrose, galactose, ribose, deoxyribose, cellulose
Sleep is a normal part of human life. Investigate the neurobiological basis of normal healthy sleep and sleep-deprivation.
Cherno Okafor Aida Stefani SBI4U December 29th, 2012 Independent Research Project Topic: Sleep is a normal part of human life. Investigate the neurobiological basis of normal healthy sleep and sleep-deprivation. Part 1: Abstracts (Summarize your findings) My report/issue is about comparing normal, healthy sleep and sleep deprivation among infants, adults, and the elderly by analyzing the neurology and physiology of sleep and the effects on the human body. First I will define what sleep is and explain its significance. Sleep is a behavioural state that is a natural part of every individual’s life. We spend about one-third of our lives asleep. Nonetheless, people generally know little about the importance of this essential activity. Sleep is not just something to fill time when a person is inactive. Sleep is a required activity, not an option. Even though the precise functions of sleep remain a mystery, sleep is important for normal motor and cognitive function. We all recognize and feel the need to sleep. After sleeping, we recognize changes that have occurred, as we feel rested and more alert. Sleep actually appears to be required for survival. Moreover, sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet
