Chemistry of Life Review

What makes a molecule polar?

• Equal sharing of valence electrons
• Unequal sharing of valence electrons
• Stealing of electrons
• Temporary charges that come and go

Which of the following is an organic compound?

• H₂O
• C₆H₁₂O₆
• NH₂
• OH

Because water has a positively charged end and a negatively charged end, it can be described as

• amphipathic
• hydrophobic
• polar
• nonpolar

Tags

NGSS.HS-ESS2-5

What property of water allows it to be such a versatile solvent that it is often called the "universal solvent?"

• Purity
• Polarity and cohesion
• High heat capacity
• Expansion upon freezing

Which of the following properties of water enables molecules to cling together as they move from the roots to the leaves of plants?

• Water expands as it freezes.
• Water is an excellent solvent.
• Water exhibits cohesive behavior.
• Water moderates temperature.

Some insects can stand on the surface of calm water. Their feet push the surface of the water down slightly, but they do not break the surface. Why?

• The insects are light enough so they do not break the hydrogen bonds holding the water molecules together
  
• The insects actually use their wings to hover slightly above the water’s surface and they only skim it with their feet.
• The insect’s feet are non-polar, so they are repelled by the polar water molecules and are pushed away from the water’s surface.
• The insects are small enough to see the individual water molecules, so they are able to step carefully from one molecule to the next
  

What are the four elements that all life is made up of?

• Hydrogen, Oxygen, Nitrogen and Carbon
• Helium, Oxygen, Neon and Carbon
• Hydrogen, Titanium, Carbon, Nitrogen
• Oxygen, Chlorine, Iron, Nitrogen

Which is not a monomer?

• nucelotide
• protein
• glucose
• amino acid

_{Who am I? I'm a polymer composed of amino acids that are linked by peptide bonds. Amino acid bonds determine my folds.} 

• Lipid
• Carbohydrate
• Protein
• Sugar

Tags

NGSS.HS-LS1-1

NGSS.HS-LS1-6

What gives water so many important properties for life?

• adhesion and cohesion

• the amount of carbon in each molecule

• energy released exothermically

• hydrogen bonds give it polarity

Tags

NGSS.HS-ESS2-5