Lecture 3: Polymerization and Proteins

Question 1

What is the carbon backbone?

Answer 1

Carbon and hydrogen atoms bonded together

Question 2

Purpose of functional groups

Answer 2

Functional groups bind to the carbon backbone and give function to a molecule

Question 3

What is a wet weight?

Answer 3

Shows what humans are made up of everything except teeth, bones or hair

Question 4

Macromolecules

Answer 4

All occur in polymers
- Proteins
-Carbohydrates
-Nucleic Acids

Question 5

Lipids

Answer 5

-Not macromolecules since they are never polymers

Question 6

Biochemical Unity

Answer 6

Macromolecules are made the exact same way in all living things meaning we can eat each other to obtain necessary biochemicals

Question 7

Polymerization

Answer 7

Monomers bonded together via covalent bonds
- Two monomers form a covalent bond and water is released
-Anabolic(requires energy)
-DNA replication, Protein Synthesis, Making of Starch

Question 8

What are proteins in terms of amino acids?

Answer 8

Proteins are polymers of amino acids

Question 9

Depolymerization

Answer 9

-Condensation reaction
-Bond between two monomers is broken with the help of a water molecule
- OH binds to one monomer and H bonds to O of other monomer (leaving to OH’s)
-Catabolic(releases energy)

Question 10

Basic Structure of all amino acids

Answer 10

Starts with an amino group, then there is a central carbon group, attached to the central carbon group there is a side chain and then also attached to the central carbon is a carboxyl group

Question 11

Nonionized Amino Acid Group

Answer 11

Amino Group is (NH2) and the carboxyl group is COOH

Question 12

Ionized Amino Acid Group

Answer 12

-Amino Acids in the human body are ionized due to pH of 7
-Amino group is NH3+ and the carboxyl group is COO-

Question 13

What would happen if pH decreased in the body?

Answer 13

-Carboxyl group would become COOH and amino group would become non-ionized leading to alterations of amino acids and future proteins

Question 14

Types of side chains(3 Types)

Answer 14

1. Non-polar side chains: mostly carbon and hydrogen
2. Polar side chains: have polar covalent bonds
3. Electrically charged side chains(NH3+ and COOH)

Question 15

What is a peptide bond?

Answer 15

Bond between two amino acids

Question 16

How does a peptide bond occur?

Answer 16

Occurs between nitrogen of amino group and carbon of carboxyl group. OH of carboxyl group is released and H of amino acid group is also released(water is released)

Question 17

What prevents amino acids from rotating freely around their peptide bonds?

Answer 17

Partial double bond character

Question 18

Are non-polar amino acids hydrophobic or hydrophilic?

Answer 18

Hydrophobic

Question 19

Are polar amino acids hydrophobic or hydrophilic?

Answer 19

Hydrophilic

Question 20

What is the primary structure and its function?

Answer 20

-The order of amino acids
-Determines the function and how proteins will fold

Question 21

Beginning and end of a polypeptide chain

Answer 21

Starts with an amino group(N-terminus)
End with a carboxyl group (C-terminus)

Question 22

Secondary Structure

Answer 22

-Does not include side chains
-Hydrogen bond forms between oxygen(from carboxyl) and hydrogen (from amino group)
-Forms either alpha-helix or beta-helix

Question 23

Primary Structure

Answer 23

-Amino acids form polypeptide chain
-Peptide bonds between each amino acid

Question 24

Alpha-Helix

Answer 24

• Side chains point outward
• hydrogen bonds form in the direction of the helix

Question 25

Beta-pleated Sheet

Answer 25

-Side chains point away from the plane

Question 26

What is special about the proline side chain?

Answer 26

-Its side chain is bonded to the nitrogen and therefore the nitrogen lacks a hydrogen needed to create the bond (O-H) bond within the polypeptide chains
-This creates a kink in the peptide chain and prevents the rotation of the N-C bond
-The hydrogen bond cannot be formed between the oxygen and hydrogen since the nitrogen now lacks an H
-The proline is thus most likely found at the end of the polypeptide chain