Day 1: Lab setup, before yeast has had a chance to begin respiring. Containers in order: Control, Glucose, Sucrose, Lactose, Starch Day 2: After 24 hours of yeast performing cellular respiration (or not!) Use the instruction sheet to help you answer any pre or post lab questions! Containers in order: Control, Glucose, Sucrose, Lactose, Starch
If you missed this lab, you have two options:
Attached below are the instructions for Lab 9. The focus of this lab was to measure the rate of photosynthesis by watching leaf discs rise. The leaves will rise from the bottom of a cup as O2 gas is produced as photosynthesis takes place. Below are pictures showing the lab setup and the data from one lab group in Period 2. Use the data to complete your lab sheet.
In this lab, we created cells using dialysis tubing, a semi-permeable film that is made in a tube shape. Inside the dialysis tubing, we put an UNKNOWN sugar solution inside the tubing (dyed blue), We made four of these. Then we put each dialysis tubing "cell" in a KNOWN concentration of sugar water: 0% sugar, 10% sugar, 20% sugar, and 30% sugar. Below are pictures of the lab set up. We measured the mass of the cells before and after being exposed to the different sugar solutions. If a cell gained mass, it was in a hypotonic solution. If a cell lost mass, it was in a hypertonic solution. If its mass was the same or nearly the same, it was in an isotonic solution. Use the data below to complete your lab packet.
Part A: Diffusion - observe the cubes below to visually identify which cube had the highest percentage of diffusion. The data table below has the measurements of the agar cubes. Use the data to complete your lab packet. Part B: Osmosis - observe the pictures below that show red onion cells before (picture 1), after exposure to 15% salt water (picture 2), and after having salt water replaced with distilled (pure) water (picture 3). Use the pictures to complete your lab packet.
Also...here is a cool video of osmosis happening in red onion cells in real time! |