AboutWalter Hintz Expertise Science teacher for over 50 years. MSc. in biology. I can answer questions in general biology, zoology, botany, anatomy and physiology and biochemistry.
Experience I have a MSc in biology and have been a science teacher for over 50 years. At present I am a faculty member at a college and a science consultant at seven catholic schools.
Publications The Ohio journal of Science
Momentum-The Journal of the Catholic Education Association
Question I have an "experiment" if you will that I have to record data on. The only information given is this:
1. 3 sac of tubing were filled with a 2M sucrose solution. The tubing is permeable only to water.
2. Each sac was weighed and then placed into a beaker containing an unknown concentration of sucrose.
3. The sacs were allowed to remain in the beakers for 2 hrs. They were removed and reweighed. the results are given on the table below.
INITIAL WEIGHT OF SAC FINAL WT OF SAC
A-2M SUCROSE 20 GRAMS 8 GRAMS
B-2M SUCROSE 20 GRAMS 18 GRAMS
C - 2M SUCROSE 20 GRAMS 36 GRAMS
Question 1) how does the tubing act as a cel membrane?
2) explain why there is a difference in weights at the end of the experiment?
3)Identify each solution Hypertonic, Hypotonic, or Isotonic?
Solution A
solution B
Solution C
4) what osmotic problem does a bacterium encounter in fresh water?
5) In salt water?
I am totally lost as to what I am supposed to be doing, and I truly don't understand a bit of it. Can u please halp??
Thanks in advance,
Shannon
Answer Question 1. The tubing only simulates a cell membrane because it allows water to pas through
Question 2 There was a difference in the sucrose concentration in the beakers
Question 3 Sacs A and B were in a beaker with a solution greater then 2M glucose so they lost water through osmosis and the concentration in the beakers was greater in A then in B
Sac B was in a beaker with no sucrose so it gained water
Remember that with osmosis water moves from a area of high concentration to on of low concentration
Solution A and B were hypotonic and C was hypertonic
Question 4 Bacterium in fresh water will gain water through osmosis
Question 5 In salt water they will lose water and dehydrate. That is why salted foods can be preserved. Bacteria that land on a salted food will dehydrate
