1) Why is the concentration of certain ions in the vacuole higher than in the cytoplasm of plant cells?
2) Name an organism which has two nuclei in it's cell.
3) Explain why the molecules of amino acids are described as polar?
Answers
Answer:
1) A vacuole is water filled membrane-bound cell organelle which contains organic as well as inorganic molecules like enzymes, ions et cetera.
The concentration of certain ions (such as protons, potassium ions) is higher in the vacuole as compared to the cytoplasm as it is mainly involved in stabilizing the cytoplasmic pH, and osmotic or turgor pressure of the cell.
It is achieved mainly by pumping these ions into the vacuole. Low pH of the vacuole also helps degradative enzymes to function properly.
2) Giardia is an example of an organism which has two nuclei in its cell.
3) The polar or non-polar nature describes the nature of the side chain attached to the amino acid. Almost all amino acids can attain positive and negative charge at particular pH due to which they are considered as polar.