Ch. 2 Additional Questions Flashcards
How can the lower density of ice protect life from freezing?
In bodies of water, ice serves as an insulating barrier to protect the life underneath from freezing.
Why is freezing dangerous to life?
Ice crystals form when water freezes that ruptures and irreversibly damage essential cell membranes.
What liquid has the highest heat capacity?
Water
How does the high heat capacity of water help warm blooded animals maintain homeostasis?
Water transports heat from warm to cool places, which helps keep the body at an even temperature.
Where does vaporization occur?
On the surface of water.
Why does it take so much energy for water to vaporize?
The hydrogen bonds between water molecules require a lot of energy to break.
How does evaporation help maintain homeostasis?
The energy taken up by evaporation helps keep an organism cool.
What is the difference between cohesion and adhesion?
Cohesion is the attraction between water molecules, adhesion is the attraction to a surface/other molecules.
What is the relationship between cohesion and surface tension?
Water’s cohesion keeps the hydrogen bonds intact which allows for surface tension to support what is floating on the water.
When may adhesion be stronger than cohesion?
Adhesion is stronger than cohesion during capillary action when the water will move across the surface due to its attraction to the other molecules.
How do hydrogen and hydroxide ions form in pure water?
Water will spontaneously dissociate into hydrogen ions H+ and hydroxide ions HO-
What makes a more acidic solution?
More H+
What makes a more alkaline solution?
More HO- or other negatively charged ions.
How do buffers help maintain homeostasis?
Buffers in the body absorb excess H+ and OH- to prevent dangerous or sharp changes in the body’s pH.
What are macromolecules and what are the main four?
Macromolecules are complex molecules, the main four are carbohydrates, lipids, proteins, and nucleic acids.
