Review

Question 1

What is a polar covalent bond?

Answer 1

unequal sharing of electrons in a covalent bond O is more electronegative than H

Question 2

Why is water polar?

Answer 2

bent shape accounts for - charge on the O side and + charge on the H side

Question 3

Explain how differences in carbon skeleton and attached functional groups cause organic molecules to have different chemical properties

Answer 3

A hydrocarbon chain can turn back on itself to form a ring compound, or spiral, a functional group affects what shape it will take and what chemical reactions it can perform

Question 4

Why are fats/oils insoluble in water?

Answer 4

they are non-polar and water is polar so fats/oils are hydrophobic

Question 5

What are waxes?

Answer 5

apolar lipid chains that form a coating on plants and animals or minerals, they protect from water loss, energy storage in plankton

Question 6

What are steroids?

Answer 6

four fused carbon rings, component of cell membranes, fluidity and singling molecules

Question 7

Which parts of the phospholipid bilayer are hydrophilic/phobic

Answer 7

hydrophobic interior/tails, hydrophilic exterior/head

Question 8

What are the tests for presence of macromolecules?

Answer 8

• benedict solution for simple sugars, turns red
• lugol’s solution for carbohydrates, turns black
• grease spot test for lipids, turns translucent
• biuret solution test for proteins, turns violet