1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Tems11 [23]
3 years ago
14

Your lab group is experimenting with the diffusion of molecules across a membrane. Dialysis tubing is used as a model cell membr

ane, because is it semi-permeable, allowing small molecules to cross the membrane, but NOT larger molecules, like starch. A starch solution is placed in the dialysis tubing and then the dialysis tubing is placed in an iodine and water solution. Iodine is used as an indicator for the presence of starch. Normally, iodine is a yellow-brown color, but in the presence of starch, it turns a deep purple. After observing the experimental setup for 20 minutes, the iodine solution remains brown, but the starch solution inside the dialysis tubing is purple and swollen. Based on what you learned from the lab, starch is MOST likely to cross the cell membrane at which of the points indicated on the diagram?

Biology
1 answer:
Margaret [11]3 years ago
5 0

Answer: the membrane channel

Explanation:

In passive diffusion, the small water molecules can move across the phospholipid bilayer seen in blue. This layer acts as a semi-permeable or selectively permeable membrane; its hydrophilic heads are attracted to water (seen facing outwards) while its water-repellent hydrophobic tails face towards each other- allowing  molecules of water to diffuse across the membrane along the concentration gradient.

Thus the water will move from an area of high concentration  to an area of low concentration, until the system reaches a steady state called equilibrium- after this, there will be no net movement of water. Similarly via osmosis, the water passes through the membrane due to the difference in osmotic pressure on either side of the phospholipid bilayer this means that the water moves from regions of high osmotic pressure/concentration to regions of low pressure/ concentration to a steady state.

The dialysis tubing mimics a semi permeable membrane; it only allows water and small molecules of iodine to cross into the bag containing starch. The tubing is impermeable to starch;  these large molecules require the aid of protein omplexes called membrane channels, in order to move across the membrane and against the concentration gradient.

You might be interested in
The element important to life that are recycle are
katovenus [111]
Circulation of chemical nutrients such as oxygen,carbon,phosphorus,nitrogen,water, and calcium. Through the biological and physical world are known as biogeochemical cycles.
3 0
3 years ago
Why are beavers a keystone pecies
oee [108]
They construct dams and create an ecosystem for other species . Because of their dam building nests become available for birds, fish population increases and waterfowl population goes up
7 0
3 years ago
What are the physical characteristics of bird cells?
kykrilka [37]
Lightweight beaks, heavy teeth, stability in flight
6 0
3 years ago
A frantic parent calls stating their child has swallowed dish soap. what should the nurse advise?
timofeeve [1]

When a child swallow a dish soap the good advice is to call poison control. There are also different reason why e get poisoned, during a health symposium a nurse teaches the group how to prevent food poisoning. The nurse evaluates that the teaching is understood when one of the participants states "Meats and cream-based foods need to be refrigerated."

6 0
3 years ago
What is the name of the structure labeled C in the diagram below?
elena-s [515]

Answer:

it is a cell membrane (d)

Hope this helps!!!

3 0
2 years ago
Other questions:
  • If 1,000 f2 offspring resulted from the cross, approximately how many of them would you expect to have red, terminal flowers?
    8·1 answer
  • A healthy environment depends on biogeochemical cycles maintaining a balance of input and output. High levels of nitrogenous com
    11·1 answer
  • The size of the iris and pupil can change size. If you walked from a bright room into a dark room, what would happen to the size
    11·1 answer
  • Where does a vulture obtain his energy
    12·1 answer
  • Approximately what percent of the Earth’s surface is covered by ocean?
    10·2 answers
  • Please answer this for me
    5·1 answer
  • What is the polynomial system of nomenclature as used in the middle ages?
    15·1 answer
  • List six other waste product of certain plants<br>pls help now​
    14·1 answer
  • Soil is a combination of tiny rock fragments and decayed plant materials how do u think soil helps a plant
    7·1 answer
  • beta-carotene is group of answer choices a retinol. absorbed more efficiently from raw foods than from cooked foods. an antioxid
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!