Proteins Details

Question 1

Components of amino acids

Answer 1

-The central carbon atom
-Amine group(-NH₂)
-Carboxyl group(-COOH)
-R-group

Question 2

Number of different types of amino acids used to make proteins

Answer 2

20

Question 3

Reaction used to link amino acids together

Answer 3

Condensation reactions

Question 4

Maximum number of amino acids in a peptide chain

Answer 4

There isn’t one(however, most polypeptide chains have between 50 and 2,000 amino acids)

Question 5

Factor which determines the sequence of amino acids in the polypeptide

Answer 5

The sequence of bases in the DNA

Question 6

Word equation for the condensation reaction between amino acids(for dipeptides)

Answer 6

Amino acid + Amino acid → Dipeptide chain + Water

Question 7

Hydroxyl group

Answer 7

OH(polar)

Question 8

Methyl group

Answer 8

-CH₃(non polar)

Question 9

Carboxyl group

Answer 9

-COOH(is charged; ionized to release H⁺ ions)

Question 10

Amine group

Answer 10

-NH₂(charged; accepts H⁺ to form NH₃)

Question 11

Phosphate group

Answer 11

-PO₃H₂

Question 12

How the 20 amino acids(that are used to make polypeptides) are produced

Answer 12

They are produced in plants by photosynthesis(these amino acids then pass to animals in their food)

Question 13

Number of essential amino acids

Answer 13

9

Question 14

Number of non essential amino acids

Answer 14

11

Question 15

Plant-based foods have too little of specific amino acids for human needs(T/F)

Answer 15

True(animal-based foods supply amino acids in the proportions needed in the human diet though)

Question 16

Not all amino acids are used in every polypeptide(T/F)

Answer 16

True

Question 17

Conditions which can denature proteins

Answer 17

-Heat
-Change in pH

Question 18

Examples of peptides

Answer 18

-Glucagon
-Myoglobin
-Titin

Question 19

Examples of polypeptides

Answer 19

-Insulin
-Beta-endorphin
-Titin
-Alpha amylase

Question 20

Levels of complexity of the structure of proteins

Answer 20

-Primary
-Secondary
-Tertiary
-Quaternary

Question 21

What characterizes the primary structure of proteins?

Answer 21

the linear sequence of amino acids in a polypeptide

Question 22

What can cause changes to conformation in carbon compounds?

Answer 22

Bond rotation

Question 23

Why is the overall conformation of proteins predictable and repeatable?

Answer 23

Cells construct proteins with amino acids in a precise position

Question 24

From which region to which region does a polypeptide go when being synthesized by a ribosome?

Answer 24

From the amino(N) terminus to the carboxyl(C) terminus

Question 25

What may happen to the polypeptide chain as it is synthesized?

Answer 25

-Parts of it may coil up to form a helix -Fold may form at some points to make the shape globular

Question 26

Why do the conformation of polypeptides tend to stay precisely the same when they are synthesized?

Answer 26

It is stabilized by intramolecular bonds between the amino acids brought together by the coiling and folding processes

Question 27

Of the components of amino acids, which group largely determines the properties of the proteins?

Answer 27

The R-group

Question 28

Number of R-groups of amino acids(which are used to make proteins) that are hydrophobic

Answer 28

9 R-groups are hydrophobic(3 of them have rings, the other 6 don't)

Question 29

Number of R-groups of amino acids(which are used to make proteins) that are hydrophillic

Answer 29

11 R-groups are hydrophillic

Question 30

Of the 11 R-groups of amino acids(which are hydrophillic), how many are never charged?

Answer 30

4 R-groups are never charged

Question 31

Of the 11 R-groups of amino acids(which are hydrophillic), how many of them are capable of having a charge?

Answer 31

7 R-groups can be charged

Question 32

Of the 7 R-groups of amino acids(which are hydrophillic and can be charged), how many of them are basic(and can be positively charged)?

Answer 32

3 R-groups are basic and can be positively charged

Question 33

Of the 7 R-groups of amino acids(which are hydrophillic and can be charged), how many of them are acidic(and can be negatively charged)?

Answer 33

4 R-groups are acidic and can be negatively charged