Biology 1306 Lab Practical 2 (Part 1) Review PDF

BIOLOGY 1306 LAB PRACTICAL 2 - REVIEW (Part 1) 1  Movement of Molecules Area of High Area of Low Concentration Concentration Diffusion is the movement of substances from an area of high concentration to an area of...

BIOLOGY 1306 LAB PRACTICAL 2 - REVIEW (Part 1) 1  Movement of Molecules Area of High Area of Low Concentration Concentration Diffusion is the movement of substances from an area of high concentration to an area of low concentration. Many molecules diffuse across cell membranes. 2  Baggies with Starch and Iodine Experimental Set-up: Starch in the beaker; Iodine in the baggie. What would be in the beaker? Starch and Iodine You would know by the color of the starch in the beaker, it would be blue/black. What would be in the baggie? Iodine You would know by the color of the The Iodine moved by the process of Iodine in the baggie – it is yellow. Diffusion 3  Baggies with Starch and Iodine Experimental Set-up: Iodine in the beaker; Starch in the baggie. What would be in the beaker? Iodine You would know by the color of the iodine in the beaker, it would be yellow. What would be in the baggie? Starch and Iodine You would know by the color of the The Iodine moved by the process of starch – the iodine would have Diffusion caused it to turn blue/black. 4  Potatoes soaked in distilled Water or in 10% NaCl How do potato slices feel if the cells have been soaked in distilled water? Stiff – the distilled water is a Hypotonic solution to the potato cells. The potato cells have gained water. The potato cells are turgid. How do potato slices feel if the cells Water moves in or out of the have been soaked in the 10% NaCl? Potato slices by the process of Limp – the 10% NaCl is a Osmosis. Hypertonic solution to the potato cells. The potato cells have lost water. *Note – 10% NaCl is water and salt. The potato cells are plasmolysed. NaCl is the solute. Water is the solvent. 5  Red Blood Cells in Solution When red blood cells are in a hypotonic solution (water), they are hemolyzed and will appear to be clear red. When red blood cells are in a hypertonic solution (10% NaCl), they are crenated and will appear to be cloudy red. Test tube A – Blood & H2O Test Tube B – Blood & 10% NaCl 6 B A  Blood cells put in distilled water, 0.9% NaCl, and 10% NaCl. Water moves in and out of the blood cells by the process of Osmosis. 10% NaCl 0.9% NaCl Distilled water Lose water No effect Gain water Crenated on the RBCs Hemolysed Appear cloudy red Optimal condition Appear clear red In a test tube. in a test tube. 7 Elodea leaf on a slide in distilled water: Hypotonic solution. Water moves into the cells by Osmosis. Chloroplast all fat & happy in a whole lot of water! The central vacuole fills with water and forces the chloroplasts away from the center of the cell and against the plasma membrane. The cell is Turgid. Central vacuole 8  Elodea leaf on a slide in 10% NaCl: Hypertonic solution. Water moves out of the cells by Osmosis Chloroplast are NOT happy! They are all pulled together in the center of the cell. The chloroplasts are pulled to the center of the cell. The plasma membrane pulls away from the cell wall. The cell is plasmolysed. 9 10 2H2O2 catalase 2H20 + O2 Catalase is an enzyme normally found Reactant Enzyme Products in many plant and animal tissues. Catalase breaks down toxic substances. It will convert hydrogen peroxide into oxygen and water. In this experiment, you will use potatoes as a source of catalase. enzyme substrate product 11  How do you know that a reaction has taken place? The presence of bubbles. What was the source of the enzyme in our experiment? Potato juice After the reaction was completed, what liquid remained in the test tube? Catalase and water During the reaction, what gas was released in the bubbles? Oxygen What happens to an enzyme when it is denatured? It will not function due to changes in the 3 deminsional structue of the enzyme. Enzymes, like proteins, can be denatured by extreme temperatures and changes in pH levels. The Reactant is the Hydrogen Peroxide The Product is Oxygen and Water The Enzyme is Catalase 12  You will be presented with test tubes and given their contents. You will be expected to predict if a reaction will take place or if it will not take place. If you predict it will not take place, explain why. Catalase at 0°C + Hydrogen peroxide Hydrogen peroxide Catalase + + Catalase at 22°C (room temp) Catalase sucrose + Hydrogen peroxide H2O + Catalase in a water bath 37°C Hydrogen peroxide + Hydrogen peroxide Boiled catalase + Hydrogen peroxide 13  You will be presented with test tubes and given their contents. You will be expected to predict if a reaction will take place or if it will not take place. If you predict it will not take place, explain why. Catalase at 0°C + Hydrogen peroxide = Yes, However, Cooler temp. slows down the reaction Hydrogen peroxide Catalase + + Catalase at 22°C (room temp) Catalase = Yes sucrose = No, + sucrose is not Hydrogen peroxide = Yes H2O a substrate for + catalase Catalase in a water bath 37°C Hydrogen peroxide = No, + no enzyme present Hydrogen peroxide = Yes Boiled catalase + Hydrogen peroxide = No, temp. denatured enzyme. 14  Catalase + Hydrogen peroxide + Water (pH7) Catalase + Hydrogen peroxide + HCl (pH 3) Station with two test tubes: one Catalase of the tubes has more catalase than + the other. When the same amt. Hydrogen peroxide of Hydrogen peroxide is simultaneously + added to both, predict what will happen. NaOH (pH 11) 1cm of Catalase 2cm of Catalase + + 4cm of Hydrogen peroxide & 4cm of Hydrogen peroxide 15  Catalase + Hydrogen peroxide + Water (pH7) = Yes Catalase + Hydrogen peroxide + HCl (pH 3) = No, pH is too low (acidic) Station with two test tubes: one Catalase of the tubes has more catalase than + the other. When the same amt. Hydrogen peroxide of Hydrogen peroxide is simultaneously + added to both, predict what will happen. NaOH (pH 11) = No, pH is too high (basic) 1cm of Catalase 2cm of Catalase + + 4cm of Hydrogen peroxide & 4cm of Hydrogen peroxide Prediction: The tube containing the greater amount of catalase will have a 16 more vigorous reaction because there are more active sites available. Experiment with liver and Hydrogen peroxide Does liver contain catalase? Yes. The experiment that was done in lab resulted in the test tube filling with bubbles (water and oxygen). This was an exergonic reaction because you could feel the heat that was being released by the reaction. Catalase IS reusable. An enzyme is NOT used up in the reaction. This can be proven by adding more Hydrogen peroxide. If a test tube of catalase and H2O2 Were left to run for 20 minutes, what substance(s) would remain in the test tube? Catalase and Water 17 Photosynthesis 6CO2 + 6H2O ==> C6H12O6 + 6O2 What cell organelle is involved in Photosynthesis? Chloroplasts What are the reactants of photosynthesis? CO2 and water 18  Chloroplast stroma Thylakoid (Individual disks) DNA Outer membrane Stacked disks - granum Inner membrane What cell organelle is involved in Photosynthesis? Chloroplast... (Light reactions in the thylakoid membrane; 19 Dark reactions in the stroma)  Chromatography What is the purpose of chromatography? Know the position of these pigments on A technique that separates different chemicals in a solution. the Chromotography strip. (In lab, pigments were separated.) What solvent is used in the separation? Chromotography solution: A: Beta carotene Petroleum ether and acetone B: Xanthophyll What 4 pigments are present in the leaves? C: Chlorophyll a Chlorophyll b, chlorophyll a, xanthophyll, beta-carotene D: Chlorophyll b Be able to identify each pigment on the chromatogram Which pigment is most soluble in the solvent? Beta-carotene (it traveled the furthest) Least soluble? Chlorophyll b (it traveled the least) How is the Rf value calculated? Rf = distance traveled by the pigment ÷ distance traveled by the solvent. Which pigment has the lowest Rf value? Chlorophyll b Which pigment has the highest Rf value? Beta-carotene 20  Cellular respiration C6H12O6 + 6O2 6CO2 + 6H2O + Energy What cell organelle is involved in cellular Respiration? Mitochondria What gas is being used by the plant in Cellular respiration? Oxygen Is the ATP being made aerobically or Anaerobically? Aerobically 21  Fermentation C6H12O6 yeast 2CO2 + 2 C2H5OH + 2ATP Is ATP being made aerobically or anaerobically? Anaerobically What organism is doing the fermenting? yeast What gas is released during fermentation? CO2 Cellular Respiration is not In which of the test tubes does fermentation take place? occuring in the Yeast + glucose = yes test tube! Yeast + lactose = no Yeast + sucrose = yes Yeast + water = no (control) We know glucose ferments the best because of the size of the CO 2 bubble in the respirometer. 22