L1-2: The Building Blocks of Life

Question 1

What are the 20-22 amino acids?

Answer 1

Alanine, Asparagine, Arginine, Aspartic acid, Cysteine, Glycine, Glutamine, Glutamic acid, Histidine, Hydroxyproline, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Proline, Selenocysteine, Serine, Tryptophan, Tyrosine, Threonine, Valine

Question 2

Which amino acids are charged?

Answer 2

-ive
Aspartic acid
Glutamic acid
+ive
Arginine
Histidine
Lysine

Question 3

Which amino acids not directly encoded?

Answer 3

Selenocysteine and Hydroxyproline

Question 4

What amount of a human is protein (dry weight %and wet weight kg)

Answer 4

~25% and 12kg wet

Question 5

What is the approximate number of proteins in the human body?

Answer 5

20,000

Question 6

What are the 4 levels of protein structure?

Answer 6

primary, secondary, tertiary and quaternary

Question 7

What 2 structures are formed from secondary protein structure?

Answer 7

alpha helix and beta pleated sheet

Question 8

What is the bond between amino acids called?

Answer 8

Peptide bond

Question 9

What are the 2 classifications of amino acids?

Answer 9

L and D amino acids

Question 10

How is the ribosome structured?

Answer 10

It has large and small sub-units

Question 11

What would be stopped when protein synthesis is a drug target? And where would the target be?

Answer 11

Peptide bond formation and at the active site of the ribosome

Question 12

Which type of amino acids do ribosomes make?

Answer 12

L-amino acids

Question 13

Why are the bonds in a tetrahedral arrangement in amino acids?

Answer 13

To minimize overlap

Question 14

What arrangement do electron shells adopt in proteins?

Answer 14

sp3 hybridization which is in a tetrahedron

Question 15

What does it mean when a carbon is chiral?

Answer 15

The different chiral forms of a molecule cannot be superimposed on each other

Question 16

How can you detect 2 different chiral molecules and what are they called?

Answer 16

Use plane-polarized light from a polarizer which rotates clockwise or anticlockwise and they are called enantiomers

Question 17

What is L/D configuration relative to?

Answer 17

D-glyceraldehyde

Question 18

What handed are alpha helicies?

Answer 18

Right handed

Question 19

What is an example of a drug used that changed enantiomers in the body?

Answer 19

Thalidomide (late 1950s)

Question 20

What are the amino acids with hydrophobic side chains?

Answer 20

Ala, Val, Ile, Leu, Met, Phe, Tyr, Trp

Question 21

What is each amino acid in a sequence called?

Answer 21

A residue

Question 22

What are the characteristics of the peptide bond?

Answer 22

Rigid and planar

Question 23

What is electronegativity?

Answer 23

Attraction of different elements for electrons due to atomic number and distance from nucleus of valence electrons

Question 24

What are the slight charges of the amide and carbonyl groups?

Answer 24

Amide- positive
Carbonyl- negative

Question 25

Why are hydrogen bonds important?

Answer 25

Secondary structure arises from backbone hydrogen bonding and higher level structure has large hydrogen bonding contribution

Question 26

how many residues per turn are there in a 100 degree repeat?

Answer 26

3.6

Question 27

What amino acids are preferred in alpha helices?

Answer 27

Ala, Glu, Leu, Met, Ile, Lys, Phe, Trp

Question 28

On average, how many residues do alpha helices contain?

Answer 28

11

Question 29

How many residue repeats do beta strands have?

Answer 29

2

Question 30

What are the preferred amino acids in beta strands?

Answer 30

Ile, Tyr and Val

Question 31

What type of handedness do beta pleated sheets usually have?

Answer 31

Right-handed twist

Question 32

What do beta-sheets often form?

Answer 32

The core of globular proteins