Edit View History marks Window Help proprofs.com Study Questi... Microsoft Of...

Question

Edit View History marks Window Help proprofs.com Study Questi... Microsoft Of... Untitled d nt st f Total Questions: 23 The rate of movement of the water molecules slows greatly 20) When temperatures reach 0 oC, ice crystals form within cell of organisms causing the cells to burst. Based on the chemical properties of water, explain why this occurs. Type your answer here: any species of insects, frogs, etc. are able to survive temperatures below 0 oC without their cells forming ice crystals and ting. How do these organisms prevent ice crystals to form in their body fluids and cells. Type your answer here:

Explanation / Answer

ANS.20) Solutution effects:

As ice crystals grow in freezing water the solutes are excluded ,causing them to become the concentrated in the remaining liquid water.high concentration of some solutes can be very damaging.

Extracellular ice formation:

when tissues are cooled slowly ,water migrates outof cell, and ice forms in the extracellular spac. to much extracellular ice can cause mechanical damage to the cell membrane due to crushing.

Dehydration:

Migration of water causing extracellular ice formation, can cause cellular dehydration.the associated stresses on the cell can cause damage directly.

ANS.21)Many organisms can survive in freezing conditions by replacing their most of the internal water with the sugur trehalose,preventing it from crystallization that otherwise damages the cell membranes.this process is known as Cryopresevation.mixture of solutes can acheive similar effects some solutes includes salts have disadvantage that may be toxic at higher concentrations . in addition to that many organisms like frogs.water bear etc.can tolerate the freezing of their blood and othher tissues.Urea is accumulated in tissues in prepartion for over wintering.and liver glycogen is converted into large quantities glucose in response to internal ice formation.both "Urea" and "Glucose" act as a cryoprotectants to limit the amount of ice that forms and reduce osmotic shrinkage of cells.

Related Questions

Navigate

• Browse (All)
• Browse E
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.