Bio 168 Hands on Lab 2

docx

School

Fayetteville Technical Community College *

*We aren’t endorsed by this school

Course

168

Subject

Biology

Date

Apr 3, 2024

Type

docx

Pages

Uploaded by MagistrateMoleMaster1065

Erika Vaughan January 24, 2024 Bio 168 Hands on Lab 2 Hands On Lab 2: Cells and Membrane Transport (3 Activities) Submission instructions  Type your answers and copy all pictures directly into this Word document. Submit it via the blackboard submission link in Word format (docx). Introduction: Cells are the basic structural and functional units of life. Your entire body is composed of cells and the substances produced by them. Each type of cell you possess has a unique structure based on its overall function, but they all share a set of common organelles that fulfill the basic needs every cell has. We will look at each of these organelles, identify them, and define their functions. One of the universal activities within the body is the movement of substances into and out of cells. Gases, nutrients, wastes, chemicals, and water must all be transported in a controlled manner for cells to maintain homeostasis. For example, if a cell contains too much or too little salt, then it will die. The plasma membrane is the major regulator of cellular transport. In this lab you will demonstrate the two simplest transport mechanisms used by the plasma membrane, diffusion and osmosis. Watch This: This video on tonicity is particularly helpful and clear on explaining this concept that many find a bit tricky. It will be quite helpful when working on activity 3 in this lab. Khan Academy Tonicity (opens in new window: 6min:30sec) Activity 1: Cellular Structure Complete the table by identifying each part of the cell (diagram on next page) and give the function of each. Both columns must be correct for credit. Structure Function 1. Golgi apparatus Modifies, packages, and distributes proteins and lipids for secretion or internal use 2. Cilia Move materials over the surface of cells 3. Peroxisome Serves as one site of lipid and amino acid degradation; breaks down hydrogen peroxide 4. Nucleus Acts as the control center of the cell. DNA within the nucleus regulates protein synthesis and therefore the chemical reactions of the cell 5. Nucleolus Facilitating ribosome biogenesis 6. Nuclear envelope Separates the contents of the nucleus from the cytoplasm and provides the 1

Erika Vaughan January 24, 2024 Bio 168 Hands on Lab 2 framework of the nucleus 7. Rough endoplasmic reticulum Synthesizes proteins, which are usually transported to the Golgi apparatus 8. Smooth endoplasmic reticulum Manufactures lipids and carbohydrates; detoxifies harmful chemicals; stores calcium 9. Centrioles Serves as centers for microtubule formation; determine cell polarity during cell division; form the basal bodies of cilia and flagella 10.Lysosome Contains digestive enzymes 11.Plasma membrane Functions as the outer boundary of the cell; controls they entry and exit of substances; receptor proteins function in intercellular communication; marker molecules enable cells to recognize one another 12.Mitochondria Are major sites of ATP synthesis when O2 is available 13.Microvilli Increase surface area of the plasma membrane for absorbtion and secretion; modified to form sensory receptors 2

Erika Vaughan January 24, 2024 Bio 168 Hands on Lab 2 3

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Erika Vaughan January 24, 2024 Bio 168 Hands on Lab 2 Activity 1 Conclusion Questions All parts of the question must be correct for credit. 14.Many of what small organelles give #7 it’s studded appearance AND what is the function of these? Ribosomes. They serve as the sight of protein synthesis. 15.What organelle is not visible on the cell above because in humans it is present only on sperm? Flagellum. 16.What are the loose strands of DNA with associated proteins found in the nucleus AND what form do these strands coil tightly into as the cell begins to divide? Chromatin, and they form mitotic chromosomes. 17.Name the 3 types of proteins that make up the cytoskeleton in order from largest to smallest. 1) Microfilaments (actin filaments). 2) Intermediate filaments. 3) Microtubules. 18. A double-layer of what molecules are the main component of #11? Membrane Transport Pre-Activity Questions Phosopholipids and cholesterol 19.To facilitate transport, the plasma membrane of a cell is selectively permeable. Define selective permeability. a. Selective permeability is being able to differentiate between the types of molecules, only letting a select few molecules pass through will blocking others. 20. Define solution and give examples of the two major components of solutions. a. A homogenous mixture formed when a solute is dissolved into a solvent. i. Ex. Mixing sugar and water, whereas sugar is the solute and water is the solvent. ii. Mixing a diluent into the Varicella vial (frozen powder live vaccine) 21.Watch this 3 minute video about concentration gradients (link opens in new window). How would you describe a concentration gradient? a. I think of it similarly to a thanksgiving plate in a sense. Overcrowded and the food has got to move somewhere else on the plate to not overload the plate and fall off. In doing so, it crosses paths with other foods (particles) causing them to mix up, resulting in a mixed region of particles (food). 22. Define diffusion Movement of molecules from a higher concentration to a lower concentration. 23. Define osmosis Movement of water from a higher concentration across a semipermeable membrane to a lower concentration. 4

Erika Vaughan January 24, 2024 Bio 168 Hands on Lab 2 24-27. Compare and contrast diffusion and osmosis. Give at least 2 differences and 2 similarities (1pt. for each difference and 1pt for each similarity). Activity 2: Diffusion In this activity, you will observe a substance diffusing through a selectively permeable membrane. As evidence of diffusion, we will use iodine, an indicator that turns blue- black the presence of starch. Materials  2-cup clear glass container o Size does not have to be exact, but it should be taller than it is wide o Drinking glasses or measuring cups work fine.  1 sandwich size resealable bag o The cheaper the bag, the better this experiment will work  ~10 drops liquid Iodine o Warning: Handle with care, toxic if ingested and can stain! o Can be obtained in any drugstore  Do NOT purchase colorless iodine! It will not work. Iodine should be brownish-yellow in color.  ~2 tablespoons Cornstarch  Water  Camera Procedure 1. Fill the glass container with 200 mL (~1 cup) of water and add 10 drops of iodine 2. Place 2-4 tablespoons of cornstarch in a plastic bag and add 100 mL of water. 3. Carefully close the bag and gently squeeze to mix the cornstarch and water. 4. Gently place the bag into the container so that the cornstarch solution is submerged in the iodine solution. 5. Gather data a. Take a picture at the start (0min) and end of your experiment (60min). Post these pictures in the results section. b. In the provided data table, record the starting color of the solution in the beaker and bag, then observe and record color changes every 15 minutes for 1 hour. Results 5

Erika Vaughan January 24, 2024 Bio 168 Hands on Lab 2 28. 0min Picture 29. 60min Picture 30. Data Table Solution 0 min 15min 30min 45min 60min Color in Container brown Brown Brown Brown Brown Color in Bag white white Off white color (tinted) Light purple purple Activity 2 Conclusion Questions 6

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Erika Vaughan January 24, 2024 Bio 168 Hands on Lab 2 31. Based on your observations, which substance moved, the iodine or the cornstarch? How can you tell? The iodine moved into the bag, whereas the cornstarch remained within the bag. The cornstarch and water changed color, but the iodine solution remained as it was. 32. What would happen if you did an experiment in which the iodine solution was in the plastic bag and the cornstarch solution was in the beaker? I believe that the iodine would seep into the cornstarch solution and causing the iodine and water combination to be brown but it would cause the cornstarch and water to become a darker brown/black color. Activity 3: Osmosis In this activity, you will observe osmosis through a selectively permeable membrane. Osmosis is easily observed in plants, as the osmotic pressure of the water is what provides support (this is why plants wilt when they need water). In this lab you will observe the effect of osmosis using a very familiar plant, the potato. Materials  2 clear glass containers o Size does not have to be exact, but shallow bowls work best  1 Potato  Salt  Water  Camera Procedure 1. Label or mark your containers #1 and #2—Any method works, as long as you can tell them apart. 2. In container 1, mix 15 m (one tablespoon) of salt with 100 ml (~1/2 cup) of water and stir until the salt is completely dissolved. 3. In container 2, fill with 100ml (~1/2 cup) of pure water. 4. Cut 2 strips of potato about the size of a French fry. They should be no thicker than 0.5 cm (~⅓ in). Make sure to remove all of the skin from the potato. 5. Gather preliminary data c. Take a picture of both potato strips at the start (0min) of your experiment. Post this picture in the results section. d. Examine each strip and record your observations of the firmness of the strips in the provided data table 6. Place one of the strips in container #1 (salt water) and the other strip in the container #2 (pure water). Make sure that both potato strips are completely submerged. 7. Leave the strips in the water for 60 minutes. 8. Gather Results e. Take a picture of both potato strips at the end (60min) of your experiment. Post this picture in the results section. 7

Erika Vaughan January 24, 2024 Bio 168 Hands on Lab 2 f. Examine each strip and record your observations of the firmness of the strips in the provided data table 33. 0min Picture 34. 60min Picture 8

Erika Vaughan January 24, 2024 Bio 168 Hands on Lab 2 35. Data Table Container Firmness @ 0 min Firmness @ 60min 1 (salt water) Firm limp 2 (Pure water) Firm firm Activity 3 Conclusion Questions 36. This experiment showed osmosis. Based on your results would you classify the salt water as hypertonic or hypotonic? Why? Since the water inside the potato was pushed out by osmosis, it would mean the salt water is hypertonic. 37. This experiment showed osmosis. Based on your results would you classify the pure water as hypertonic or hypotonic? Why? The water was hypotonic, because in this water, the potato retained its water. 38-46: Hypothetically, use red blood cells to explain osmosis and states of tonicity. Red blood cells naturally are approximately 0.9% salt in content. We introduced red blood cells to the following solutions: A. 100% water B. 0.9% saline C. 10% saline Match solutions A, B, or C with the criteria (each letter used 3x): Solution Type Solution A, B, or C Net Water Movement Solution A, B, or C Cell Change Solution A, B, or C Hypertonic 38.C Into Cell 41.A No Change 44.B Hypotonic 39.A No Water Movement 42.B Crenation 45.C Isotonic 40.B Out Of Cell 43.C Swelling/ Lysis 46.A 9

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Bio 168 Hands on Lab 2

Related Documents