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Biological Sciences
BISC 101
Derek Bingham

Lab Review 1 Objective Lens Total Magnification Diameter (µm) 4x 40x 4500 µm 10x 100x 1800 µm 40x 400x 450 µm Microscope Drawing Format: Osmosis and Diffusion Lab: control = substance (i.e., glucose) + reagent control = dH 2 + reagent Smaller substances are able to diffuse through the semipermeable membrane while larger substances cannot. Diffusion can only occur from [HIGH] to [LOW]. Part A: Set-Up of Dialysis Tubing 1. Retrieve well-soaked dialysis tubing (~6” long). 2. Fold one end over (~1”) and apply clamp to the seal that end of the tubing. 3. Open other end of tubing and slowly dispense 3 mL of each into it: protein, starch, glucose, and NaCl 4. Squeeze air from intestine. Fold the open end over 1” and clamp. 5. Rinse tubing in tap water, blot dry, weigh, and record the weight in Table 1. 6. Place intestine in a 250 mL beaker. Add tap water until tubing is submerged. Part B: Sampling of Water Surrounding the Intestine and Intestinal Contents 1. Label four test tubes: G10, S10, P10, N10 2. Label four more test tubes: G20, S20, P20, N20 Lab Review 2 3. After the tubing has sat in the water for 10 minutes, use a pipette to transfer 20 drops of water from the beaker into the G10, S10, P10, and N10 test tubes. Place them into a TTR for later. 4. After the tubing has sat in the water for an additional 10 minutes, pipette 20 drops of water from the beaker into the G20, S20, P20, and N20 test tubes. Place them into the TTR for later. 5. Remove intestine from the beaker and pat dry. Weigh it and record the weight in Table 1. 6. Label four more test tubes: G-IC, S-IC, P-IC, N-IC 7. Open and empty the tubing contents into a clean beaker. 8. Using a new pipette, add 20 drops of the intestine contents into each of the G-IC, S-IC, P-IC, and N-IC test tubes. Place them into the TTR for later. Part C: Nutrient Testing Setting up the negative controls: 1. Label four test tubes: G-, S-, P-, N- 2. Add 20 drops distilled water (dH O)2to each of these test tubes. 3. Place tubes in TTR for later. Setting up the positive controls: 1. Label four test tubes: G+, S+, P+, N+ 2. Using the dropper bottles labeled “glucose”, “starch”, “protein”, and “NaCl”, add 20 drops into each appropriately labeled tubes. Nutrient testing: 1. Check that you have 20 test tubes, with 4 groups of 5 tubes. Each group represents a nutrient: glucose, starch, protein, and NaCl. The five tubes in each group are labeled -, +, 10, 20, and IC. 2. Test for Glucose a. Add 10 drops of Benedict’s reagent to all G tubes, and gently mix. b. Place tubes in hot water bath (80 C) for 10 minutes. c. Glucose absent = clear blue d. Glucose present = opaque green (a little glucose) / yellow, orange, or red (a lot of glucose). e. Record results in Tables 2 & 3. 3. Test for starch a. Add 5 drops of Lugol’s iodine to all S tubes. b. Starch absent = yellowish c. Starch present = blue/black or purple d. Record results in Tables 2 & 3. 4. Test for protein a. Add 10 drops of Biuret reagent to all P tubes. b. Protein absent = light blue c. Protein present = violet/purple d. Record results in Tables 2 & 3. 5. Test for NaCl a. Add 5 drops of silver nitrate reagent to all N tubes. b. NaCl absent = clear c. NaCl present = white precipitate d. Record results in Tables 2 & 3. Lab Review 3 Results: Table 1. Weight of Intestine Before Weight (g) After Weight (g) Difference in Weight (g) Gain or Loss? 21.9 22.8 0.9 Gain Table 2. Controls Nutrient Tested For Positive Control (Colour) Negative Colour (Colour) Glucose Orange Clear blue Starch Black yellow Protein Purple Light blue NaCl Precipitate Clear Table 3. Nutrient Test Results After 10 Minutes After 20 Minutes Intestinal Contents (IC) Nutrient Tested For (+/-, colour) (+/-, colour) (+/-, colour) Glucose Light blue, - Opaque green, + Orange, + Starch Yellow, - Yellow, - Black, + Protein Blue, - Blue, - Violet, + NaCl Precipitate, + Precipitate, + Precipitate, + Questions What are the purposes of the positive and negative controls in this experiment?  For comparison, to see what it would look like if the colour is absent or present Which substances (glucose, starch, protein, NaCl) were able to diffuse through the dialysis tubing?  NaCl did a little bit after 10 minutes  NaCl (more) and glucose did after 20 minutes What explains why some substances might pass through the membrane while others do not?  Mainly depends on the size  Starch and protein were too big What evidence is there, if any, in your experiment that osmosis has occurred? What are the conditions in your experiment that would result in osmosis?  Tubing weighed more  Membrane was selectively permeable and it was in water. Therefore, some substances diffused. Types of Bones:  Long – humerus, femur  Short – carpals and tarsals  Flat – skull bones, scapula, sternum  Irregular – hyoid, sacrum, vertebrae Lab Review 4 Types of Joints: Structural Classification 1. Fibrous – bones held together by dense irregular CT (rich in collagen fibres) a. Sutures – between skull bones b. Syndesmoses – above the ankle where the fibula and tibia converge i. Gomphosis – tooth sockets c. Interosseous membrane – radius/ulna and fibula/tibia 2. Cartilaginous – bones held together by cartilage a. Synchondrosis – between vertebrae b. Symphysis – between pubic bones 3. Synovial – bones forming the joint has a synovial cavity, united by dense irregular CT (of an articular capsule) and often by ligaments; example = knee joint Functional Classification 1. Synarthrosis – immovable 2. Amphiarthrosis – slightly movable 3. Diarthrosis – freely movable Muscles Origin – attachment of a muscle’s tendon to the stationary bone Insertion – attachment of a muscle’s tendon to the movable bone  A lever is a rigid structure that moves around the fixed point (fulcrum)  Effort causes movement; the force exerted by muscular contraction  Load opposes movement; the weight of the body part or some resistance that the moving body part is trying to overcome (i.e., a heavy object in your hand).  Motion occurs when the effort exceeds the load Distance between fulcrum and load and the point at which the effort is applied determines whether a given lever operates at a mechanical advantage or a mechanical disadvantage  Load is closer to the fulcrum, effort is farther from the
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