Biochemistry - The Chemistry of Life

Which of these elements MUST be present in order for a molecule to be considered organic?
1. carbon, C
2. Hydrogen, H
3. Oxygen, O
4. Chlorine, Cl
5. Nitrogen, N
6. Iron, Fe
Which six elements make up most of the mass of living cells?
1. Carbon, C
2. Hydrogen, H
3. Phosphorus, P
4. Sulfur, S
5. Oxygen, O
6. Nitrogen
7. Iron, Fe
8. Sodium, Na
9. Potassium, K
10. Helium, He
The bonds between atoms in organic molecules such as sugars, fats and proteins are
1. ionic bonds
2. covalent bonds
3. metallic bonds
4. nuclear bonds
Proteins are made up of long chains of which of these building blocks?
1. sugars
2. amino acids
3. fatty acids
4. glycerol molecules
5. nucleic acids
The organic molecules that carry the genetic code of a cell belong to which class of molecules
1. nucleic acids
2. proteins
3. lipids
4. starches
5. steroids
Which of the following would provide the greatest amount of energy when burned by cells?
1. one gram of protein
2. one gram of fat
3. one gram of sugar
4. one gram of starch
The building blocks of a triglyceride molecule are
1. amino acids and glycerol
2. nucleic acids and amino acids
3. glycogen and fatty acids
4. fatty acids and glycerol
5. sugars and starches
Which of the following is not normally a function of proteins in healthy cells?
1. a component of cell membranes
2. long-term energy storage
3. functioning as enzymes
When sugars polymerize in long chains, they may form any of the following except:
1. glycogen
2. cellulose
3. starch
4. proteins
Examples of nucleic acids include
1. DNA and RNA
2. amino acids and fatty acids
3. sugars and starches
4. fats and proteins
Which of the following is an example of an organic chemical compound?
1. sodium chloride, NaCl
2. glucose, C₆H₁₂O₆
3. carbon dioxide, CO₂
4. sufur trioxide, SO₃
When electrons are shared between atoms of nonmetals, a(n) ________________ bond is formed.
1. covalent
2. ionic
3. metallic
4. nuclear
When a bond results from the transfer of electrons between atoms, it's a(n) ________________ bond that has formed.
1. covalent
2. ionic
3. metallic
4. nuclear
Assuming you can digest all of them, which of the following carbohydrates has the greatest energy value per gram?
1. sugar
2. starch
3. cellulose
4. glycogen
5. none of these, because they all have the same energy value