EBIO 1210 MIDTERM 1: LIPIDS; QUESTIONS WITH CORRECT
ANSWERS
What are four features of a polyunsaturated fatty acid? -- Answer ✔✔ 1. It is fluid at
room temperature.
2. It has two or more kinks.
3. It has two or more C=C bonds.
4. It has a lower energy content than a saturated fatty acid with the same number of C
atoms.
What is the relationship between dehydration synthesis and hydrolysis? -- Answer ✔✔
Dehydration synthesis creates polymers and hydrolysis creates monomers.
What are all life's large molecules synthesized by and broken down by? -- Answer ✔✔
Removal of a water molecule; addition of a water molecule.
How many molecules of water are needed to completely break down a polymer
consisting of five monomers? -- Answer ✔✔ Four
The polarity of water molecules results in _______ bonds between water molecules,
and make a water molecule stick to any molecules with _______ bonds or _________
regions. -- Answer ✔✔ Hydrogen; polar covalent; charged.
In a polar covalent bond, how are the electrons configured? -- Answer ✔✔ Tightly held
by one of the atoms forming the bond?
What is one example of a non-polar covalent bond? -- Answer ✔✔ C-H bonds
Predict with which partner an oxygen atom (O) will most likely form a non-polar
covalent bond. -- Answer ✔✔ With another oxygen (O) atom.
, What are four properties shared by carbon dioxide and water? -- Answer ✔✔ 1. Low
reactivity
2. Polar covalent bonds
3. Low chemical potential energy
4. Formed when hydrocarbons are burned with oxygen
Polar covalent bonds form between atoms with what degree to which they attract
electrons? -- Answer ✔✔ An intermediate difference in the degree to which they attract
electrons.
Non-polar covalent bonds form between atoms with what degree to which they attract
electrons? -- Answer ✔✔ A similar, or the same, degree to which they attract electrons.
Ionic bonds form between atoms with what degree to which they attract electrons? --
Answer ✔✔ The largest difference in the degree to which they attract electrons.
Fill in the blank. Na+ and Cl- in table salt are held together by __________ bonds. --
Answer ✔✔ Ionic
Why is fat better suited for storage of energy than a phospholipid? -- Answer ✔✔ The
fat has three fatty acid chains and therefore contains more C-H bonds.
What are three reasons why a phospholipid is better suited for forming biological
membranes than a fat. -- Answer ✔✔ 1. Possesses a phosphate-containing hydrophilic
head group instead of a third fatty acid chain.
2. Has both hydrophobic portions and portions containing electrical charges.
3. Is able to form a bilayer that acts as a barrier for the diffusion of hydrophilic
substances.
Cholesterol is the starting material for which substances? -- Answer ✔✔ Estrogen and
testosterone, steroid stress hormones, but not fats.
What are the four major classes of life's large biological molecules? -- Answer ✔✔
Nucleic acids, proteins, lipids, polysaccharides.
ANSWERS
What are four features of a polyunsaturated fatty acid? -- Answer ✔✔ 1. It is fluid at
room temperature.
2. It has two or more kinks.
3. It has two or more C=C bonds.
4. It has a lower energy content than a saturated fatty acid with the same number of C
atoms.
What is the relationship between dehydration synthesis and hydrolysis? -- Answer ✔✔
Dehydration synthesis creates polymers and hydrolysis creates monomers.
What are all life's large molecules synthesized by and broken down by? -- Answer ✔✔
Removal of a water molecule; addition of a water molecule.
How many molecules of water are needed to completely break down a polymer
consisting of five monomers? -- Answer ✔✔ Four
The polarity of water molecules results in _______ bonds between water molecules,
and make a water molecule stick to any molecules with _______ bonds or _________
regions. -- Answer ✔✔ Hydrogen; polar covalent; charged.
In a polar covalent bond, how are the electrons configured? -- Answer ✔✔ Tightly held
by one of the atoms forming the bond?
What is one example of a non-polar covalent bond? -- Answer ✔✔ C-H bonds
Predict with which partner an oxygen atom (O) will most likely form a non-polar
covalent bond. -- Answer ✔✔ With another oxygen (O) atom.
, What are four properties shared by carbon dioxide and water? -- Answer ✔✔ 1. Low
reactivity
2. Polar covalent bonds
3. Low chemical potential energy
4. Formed when hydrocarbons are burned with oxygen
Polar covalent bonds form between atoms with what degree to which they attract
electrons? -- Answer ✔✔ An intermediate difference in the degree to which they attract
electrons.
Non-polar covalent bonds form between atoms with what degree to which they attract
electrons? -- Answer ✔✔ A similar, or the same, degree to which they attract electrons.
Ionic bonds form between atoms with what degree to which they attract electrons? --
Answer ✔✔ The largest difference in the degree to which they attract electrons.
Fill in the blank. Na+ and Cl- in table salt are held together by __________ bonds. --
Answer ✔✔ Ionic
Why is fat better suited for storage of energy than a phospholipid? -- Answer ✔✔ The
fat has three fatty acid chains and therefore contains more C-H bonds.
What are three reasons why a phospholipid is better suited for forming biological
membranes than a fat. -- Answer ✔✔ 1. Possesses a phosphate-containing hydrophilic
head group instead of a third fatty acid chain.
2. Has both hydrophobic portions and portions containing electrical charges.
3. Is able to form a bilayer that acts as a barrier for the diffusion of hydrophilic
substances.
Cholesterol is the starting material for which substances? -- Answer ✔✔ Estrogen and
testosterone, steroid stress hormones, but not fats.
What are the four major classes of life's large biological molecules? -- Answer ✔✔
Nucleic acids, proteins, lipids, polysaccharides.
