Stucture Of Proteins

Question 1

what makes up a peptide?

Answer 1

many amino acids

Question 2

what is the basic structure of an amino acid?

Answer 2

1. amine group (N, H, H)
2. R-group (have a range of chemical groups in different amino acids)
3. carboxyl group (C, O, O, H)

Question 3

what bond between amino acids?

Answer 3

peptide bonds

Question 4

where do amino acids join together and what type of reaction is this?

Answer 4

amino acids bond at amine group and carboxyl group and this makes a condensation reaction.

Question 5

when many amino acids are joined together by peptide bonds a polypeptide is formed. what enzyme catalyzes this reaction at the sites of protein synthesis?

Answer 5

peptidyl transferase found in ribosomes

Question 6

what determines the shape, and therefore the function, of an polypeptide?

Answer 6

the different range of R-groups

Question 7

what are the different level of protein structure?

Answer 7

Primary structure
Secondary structure
Tertiary structure
Quaternary structure

Question 8

what is meant by a Primary structure? what bonds are involved?

Answer 8

Primary structure is the sequence of which amino acids are joined. it is directed by information carried within DNA. The only bonds involved are peptide bonds

Question 9

what is meant by a secondary alpha structure? what bonds are involved?

Answer 9

when the O, N, H atoms of the basic, repeating structure of amino acids interact. hydrogen bonds are formed within the amino acid chain, pulling it into a coil shape.

Question 10

what are the two types of secondary structure ?

Answer 10

Alpha and Beta

Question 11

what is meant by a secondary Beta structure? what bonds are involved?

Answer 11

polypeptide chains can lie parallel to one another joined by hydrogen bonds, forming sheet like structures.

Question 12

what is meant by a Tertiary structure?

Answer 12

tertiary structure is the folding of a protein into its final shape. the coiling of the secondary structure causes the R-groups to be closer together and therefore interact.

Question 13

what bonds are involved in tertiary structure?

Answer 13

1. hydrophobic and hydrophillic interactions - weak interactions between polar and non-polar R-groups
2. hydrogen bonds - these are the weakest of the bonds formed
3. ionic bonds - these are stronger hydrogen bonds and form between oppositely charged R-groups
4. disulfide bonds - these are covalent and the strongest of the bonds but only form with R-groups containing sulfur atoms.

Question 14

what is a Quaternary structure?

Answer 14

the association of two or more individual protein subunits.

Question 15

name two Quaternary structures?

Answer 15

hemoglobin and insulin

Question 16

what is the general name for enzymes that breakdown peptide bonds?

Answer 16

proteases