protein structure

Question 1

define the primary structure of a protein

Answer 1

the order of amino acids in a polypeptide chain

Question 2

what bond holds the shape of an alpha and beta pleated sheet

Answer 2

hydrogen bonds

Question 3

what level of structure do alpha helices and beta pleated sheets have

Answer 3

secondary structure

Question 4

name 2 secondary structure proteins

Answer 4

alpha helix and beta pleated sheet

Question 5

how are secondary structure proteins termed that related to their function

Answer 5

as the formation of either alpha helix or beta pleated sheet relates to its function as its crucial for its overall 3D shape which influences its ability to perform its biological role

Question 6

name the 4 types of bonds that can form between R groups in a tertiary structure protein

Answer 6

-hydrogen bond
-covalent bond
-disulphide bridge
-ionic bond

Question 7

give 3 examples of a tertiary structure protein

Answer 7

-enzymes
-haemoglobin
-antibodies

Question 8

what is a quaternary structure protein

Answer 8

overall 3D arrangement of multiple polypeptide chains within a protein

Question 9

name 1 quaternary structure protein and its function

Answer 9

haemoglobin which is responsible for transporting oxygen in blood

Question 10

what is the sequence of amino acids in the primary structure determined by

Answer 10

its determined by DNA as 1 gene codes for 1 polypeptide

Question 11

what bond is between each amino acid

Answer 11

a peptide bond

Question 12

what is the secondary structure of a protein

Answer 12

the shape that the polypeptide chain forms due to hydrogen bonding

Question 13

why do hydrogen bonds determine the secondary structure of a protein

Answer 13

as hydrogen bonds twist and fold the polypeptide forming an alpha helix or a beta pleated sheet which is less common

Question 14

what is the tertiary structure of a protein

Answer 14

the alpha helix of the secondary protein is further folded and twisted to give a more complex, compact 3D structure.

Question 15

What is the tertiary structure shape maintained by

Answer 15

hydrogen bonds, covalent bonds, disulphide bridges and Ionic bonds

Question 16

how many genes are needed to code for haemoglobin

Answer 16

4 as there are 4 polypeptide chains

Question 17

Structure of globular proteins

Answer 17

they are compact and folded into spherical molecules

Question 18

As globular proteins are folded into spherical molecules what does this make them

Answer 18

soluble in water so they have many different functions

Question 19

what are the functions of globular proteins

Answer 19

-enzymes
-antibodies
-plasma proteins
-hormones

Question 20

name an example of a globular protein

Answer 20

haemoglobin

Question 21

what does haemoglobin consist of

Answer 21

its consist of 4 folded polypeptide chains which at the centre of each is the iron containing group, harm

Question 22

structure of fibrous proteins

Answer 22

they are long thin molecules, which consist of polypeptides in parallel chains or sheets with cross linkages to form long fibres

Question 23

due to their shape what are fibrous proteins

Answer 23

in soluble in water

Question 24

what are the functions of fibrous proteins

Answer 24

they have structural functions as they are strong and tough

Question 25

what do fibrous proteins form due to the cross linkages which form long fibres

Answer 25

keratin which is the protein in hair

Question 26

give an example of a fibrous protein

Answer 26

collagen

Question 27

how does collagen being a fibrous protein link to its function

Answer 27

as it provides the strength and toughness needed in tendons

Question 28

what does a single fibre consist of

Answer 28

3 identical polypeptide chains that are twisted around each other that look like a rope

Question 29

how many polypeptides does haemoglobin have compared to collagen

Answer 29

haemoglobin has 4 whereas collagen has 3

Question 30

what are the 3 chains in a single fibre linked by and what does this make the molecule

Answer 30

the 3 chains are linked by hydrogen bonds which makes the molecule very stable

Question 31

how are the polypeptides present in haemoglobin different to those in collagen

Answer 31

as in haemoglobin each polypeptide molecule is different whereas in collagen each polypeptide molecule is the same

Question 32

what is the highest level of protein structure presents in haemoglobin compared to collagen

Answer 32

haemoglobin has the highest level of protein structure, quaternary whereas collagen has the highest protein structure of secondary structure