Awhite starch solution was poured into a length of dialysis tubing and the ends were tied. the tubing was then dropped into the beaker of iodine solution. after 10 minutes, the white starch solution turned black, and the iodine water remained red. what cellular structure was the dialysis tubing most likely representing in this experiment

Cell membrane

Explanation:

The cell membrane is mainly composed of the lipid bilayer and embedded proteins. The hydrophobic core of the cell membrane does not allow the polar, charged, and large substances to move through it freely. However, the non-polar and small substances can diffuse through the membrane. Therefore, cell membranes are semipermeable and regulate the entry and exit of substances from cells.

In the given experiment, iodine molecules from the beaker enter the dialysis tube and turned the starch solution black. On the other hand, the large starch molecules were not allowed to diffuse across the dialysis tube and there was no change in the color of the iodine solution present in the beaker. This represents that the dialysis tube served as a semipermeable membrane and allowed only selected molecules to pass through it.

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.