Week 4

Question 1

_____________ the building blocks of proteins.

Answer 1

Amino Acids.

Question 2

Amino acids contain ____________ and _____________ functional groups.

Answer 2

Amine and carboxylic acid.

Question 3

In nature the ___________ enantiomer of the amino acid is commonly found.

Answer 3

L

Question 4

______________ is a molecule that possesses both a positive and negative charge.

Answer 4

Zwitterion

Question 5

_____________ side chains are non polar and incapable of hydrogen bonding.

Answer 5

Hydrophobic

Question 6

_____________charged amino acids contain a carboxyl group and are commonly ____________ at physiological pH.

Answer 6

Negatively, deprotonated.

Question 7

______________ charged amino acids include lysine, arginine, and histidine.

Answer 7

Positively

Question 8

Amino acids serve a variety of roles in biochemistry including:

Answer 8

1. Lipid metabolism
2. Amino acid catabolism
3. Neurotransmission

Question 9

Why is proline the least flexible amino acid?

Answer 9

Its side chain is bonded to its amino group.

Question 10

_________ is the linkage between two amino acids.

Answer 10

Peptide bond.

Question 11

A peptide bond is an _________ linkage between the __________ group of amino acid and the ___________ group of the next.

Answer 11

Amide,carboxyl, amino.

Question 12

A _____________ molecule is removed in order for an amide bond to form.

Answer 12

Water.

Question 13

_____________ are nonprotein groups required for protein binding or activity.

Answer 13

Cofactor.

Question 14

Cofactors can be divided into two common categories:

Answer 14

Minerals(metal and ions) and vitamins (small organic groups.

Question 15

___________ are enzymes that catalyze phosphorylation reaction.

Answer 15

Kinases.

Question 16

____________ is typically the source of phosphate.

Answer 16

ATP.

Question 17

______________ can change the activity of an enzyme and is thought to act as switch in the cell.

Answer 17

Phosphorylation.

Question 18

A peptide bond is normally an amide but also is capable of mildly acting as what?

Answer 18

An oxime.

Question 19

What are the 4 levels of protein structure?

Answer 19

1. Primary
2. Secondary
3. Tertiary
   4.Quaternary

Question 20

The _____________ structure is the linear arrangement of amino acids.

Answer 20

Primary.

Question 21

The ____________ structure is held together by hydrogen bonding.

Answer 21

Secondary.

Question 22

The secondary structure consists of two major structural elements:

Answer 22

Alpha helix and Beta sheet

Question 23

____________ is the most common structure observed in proteins.

Answer 23

Alpha helix

Question 24

_____________ can be parallel or anti-parallel.

Answer 24

Beta sheet.

Question 25

In anti-parallel beta sheets the hydrogen bonds are __________.

Answer 25

Linear.

Question 26

In parallel beta sheets the hydrogen bonds are __________.

Answer 26

Horizontal.

Question 27

___________ and ____________ limit the flexibility of the peptide chain.

Answer 27

Hairpin and Loops.

Question 28

____________ structure gives the overall shape of the protein.

Answer 28

Tertiary.

Question 29

___________ are combinations of secondary structure.

Answer 29

Motifs

Question 30

___________ pieces of a protein that retain their structure in the absence of the rest of the protein.

Answer 30

Domains.

Question 31

What are the bonding forces involved in stabilizing tertiary structure?

Answer 31

1. Hydrogen bonding 2. London dispersion forces 3. Dipole-dipole interactions 4. Salt bridges 5. Cation interactions 6. Disulfide bonds

Question 32

___________ describes the phenomenon in which hydrophobic groups cluster together.

Answer 32

Hydrophobic effect.

Question 33

____________ structure is a complex structure that incorporates multiple subunits or different proteins.

Answer 33

Quaternary

Question 34

Which amino acid can donate the most hydrogen bonds?

Answer 34

Arginine.

Question 35

__________ a protein that acts as a pore in the membrane, it selectively allows water to pass in and out of the cell.

Answer 35

Aquaporin.

Question 36

Aquaporin is a ___________ protein that consists of 6 transmembrane alpha helices.

Answer 36

Transmembrane.

Question 37

__________ is an enzyme that cleaves dietary into peptides.

Answer 37

Chymotrypsin.

Question 38

Chymotrypsin is produced by the _________ and secreted into the ____________.

Answer 38

Pancreas, Intestinal lumen.

Question 39

Chymotrypsin is composed of __________ beta barrels and ____________ short alpha helix.

Answer 39

Two and one.

Question 40

__________ is a fibrous protein mostly concentrated in muscle and connective tissue.

Answer 40

Collagen.

Question 41

Collagen is composed of a triple helix that contains __________, _____________, and ______________.

Answer 41

Glycine, proline, and hydroxyproline.

Question 42

____________ is a globular, tetrameric protein found in red blood cells.

Answer 42

Hemoglobin.

Question 43

Hemoglobin uses heme as a ___________ for each subunit.

Answer 43

Cofactor.

Question 44

Hemoglobin is a ____________ protein.

Answer 44

Transport.

Question 45

Collagen is a __________ protein.

Answer 45

Structural.

Question 46

_____________ are molecules of the immune system that recognize and bind to antigens.

Answer 46

Immunoglobulins.

Question 47

Immunoglobulins are __________ proteins.

Answer 47

Binding.

Question 48

____________ is a protein hormone produced by pancreatic beta cells.

Answer 48

Insulin.

Question 49

Interrupted or impaired insulin signaling can result in __________.

Answer 49

Diabetes.

Question 50

____________ diabetes is a failure to produce insulin.

Answer 50

Type I

Question 51

___________ diabetes insulin is not received.

Answer 51

Type II

Question 52

__________ acts as molecular motor in which energy is used to elicit a muscle contraction and transport vesicles in the cell.

Answer 52

Myosin.

Question 53

Myosin contains___________ chains and ____________ chains.

Answer 53

Heavy and light.

Question 54

_____________ chain interacts with the cytoskeletal protein_________.

Answer 54

Heavy, actin.

Question 55

__________ chain plays a role in binding Ca+2.

Answer 55

Light chains.

Question 56

Myosin is a _____________ protein.

Answer 56

Molecular motor.

Question 57

How many subunits does hemoglobin have?

Answer 57

4