Intro to Biochemistry

Question 1

Friedrich Wohler synthesized the organic compound ______ by heating the inorganic compound _________

Answer 1

Friedrich Wohler synthesized the organic compound urea by heating the inorganic compound ammonium cyanate

Question 2

What was shown for the first time by Friedrich Wohler’s experiment of synthesizing urea from the heating of ammonium cyanate?

Answer 2

That compounds found exclusively in living organisms could be synthesized from common inorganic substances

Question 3

Who discovered stereoisomers?

Answer 3

Louis Pasteur

Question 4

What are two major breakthroughs in the history of biochemistry mentioned in the textbook?

Answer 4

1. Identification of enzymes as catalysts of biological reactions
2. Identification of nucleic acids as information molecules

Question 5

The identification of enzymes as catalysts of biological reactions resulted in part from research of ________ who showed that yeast cells could catalyze the fermentation of glucose to alcohol and CO2

Answer 5

The identification of enzymes as catalysts of biological reactions resulted in part from research of Eduard Buchner who showed that yeast cells could catalyze the fermentation of glucose to alcohol and CO2

Question 6

What two concepts did Fischer propose about enzymes?

Answer 6

1. During catalysis an enzyme and it’s reactant (substrate) combine to form an intermediate compound
2. Only a molecule with a suitable structure can serve as a substrate for a given enzyme

Question 7

What is a key property of enzyme catalysis? (ie what effect does a catalyst have on a reaction)?

Answer 7

Enzyme catalysis allows biological reactions to occur much faster than they would without a catalyst

Question 8

In addition to speeding up reaction rates, what other effect does catalysis have on biological reactions?

Answer 8

Produce very high yields with few by-products

ie must more efficient than organic reactions because by-products can be toxic and forming them wastes energy

Question 9

Which three researchers conducted an experiment that led to the conclusion that nucleic acid (DNA) is the genetic material (carries information)

Answer 9

Oswald Avery, Colin Macleod and Maclyn McCarty

Question 10

What does the central Dogma state?

Answer 10

The unidirectional flow of information from nucleic acid to protein

DNA -transcibed->RNA -translated-> protein

Question 11

What six non-metal elements make up 97% of the weight of most organisms?

Answer 11

1. C
2. H
3. N
4. O
5. P
6. S

Question 12

What are the 5 ions essential in all species?

Answer 12

1. Ca²⁺
2. K⁺
3. Na⁺
4. Mg²⁺
5. Cl^-

Question 13

Ester and ether linkages are common in ______ and _____

Answer 13

Ester and ether linkages are common in Fatty Acids and Lipids

Question 14

Amide linkages are found in:

Answer 14

Amide linkages are found in: Proteins

Question 15

Phosphate Ester and Phophoanhydride linkages occur in:

Answer 15

Phosphate Ester and Phophoanhydride linkages occur in: Nucleotides

Question 16

What is the most important difference between biochemical reactions and reactions that occur in a laboratory?

Answer 16

Almost all biochemical reactions are catalyzed by enzymes and thus proceed at very high rates

Question 17

What is the difference between in vivo and in vitro

Answer 17

• in vivo* = takes place inside an organism
• in vitro* = takes place under laboratory conditions

Question 18

What is a macromolecule?

Answer 18

Biological macromolecules are usually a form of polymer created by joining many smaller organic molecules (monomers) via condensation (removal of the elements of water)

Question 19

How is each monomer of a given polymer added?

Answer 19

By repeating the same enzyme-catalyzed reaction.

Question 20

What is the functional group:

R-OH

Answer 20

Alcohol

Question 21

What is the functional group?

Answer 21

Aldehyde

(carbonyl group (C=O) is terminal)

Question 22

What is the functional group?

Answer 22

Ketone

(carbonyl group (C=O) is internal)

Question 23

What is the functional group?

Under most biological conditions these exist as _________

Answer 23

Carboxylic acid

Under most biological conditions carboxylic acids exist as carboxylate anions:

Question 24

What is the functional group?

Answer 24

Thiol

Question 25

Covalent bonds between monomers are organized with directional patterns of connectivity. What does this mean?

Answer 25

Directionality = all covalen bonds are in the same orientation (asymmetry in bonds connecting monomers)

Question 26

What type of bond connects amino acids together to form proteins?

Answer 26

Peptide bond

(aka amine bonds) Nitrogen to carbonyl

Question 27

What type of bond joins nucleotides together to form nucleic acids?

Answer 27

Phosphodiester bond

Question 28

What type of bond joins monosaccharides together to form polysaccharides?

Answer 28

Glycosidic bond

Question 29

Which bonds are stronger, hydrogen bonds or covalent bonds?

Answer 29

Hydrogen bonds are MUCH weaker than covalent bonds. But are more numerous