Proteins 2.1.2 (k,l,m,n,o)

Question 1

monomer of a protein?

Answer 1

amino acids

Question 2

what is formed with two amino acids?

Answer 2

a dipeptide

Question 3

what is an amino acid chain?

Answer 3

a polypeptide

Question 4

what is the general structure of an amino acid?

Answer 4

Question 5

what bonds link amino acids together?

Answer 5

peptide bonds

Question 6

what reaction forms peptide bonds?

Answer 6

condensations

a molecule of water is produced

Question 7

what reaction destroys peptide bonds?

Answer 7

hydrolysis

Question 8

what are the levels to protein structure?

Answer 8

primary
secondary
tertiary
quaternary

Question 9

what is the primary structure of a protein?

Answer 9

the sequence of amino acids in a polypeptide chain

Question 10

what bonds are present in the primary structure?

Answer 10

peptide bonds

Question 11

what is the secondary structure of a protein?

Answer 11

the coiling of the polypeptide chain into:
- alpha helix
- beta pleated sheet

Question 12

alpha helix

Answer 12

Question 13

beta-pleated sheet

Answer 13

Question 14

what bonds are present in the secondary structure?

Answer 14

peptide bonds
hydrogen bonds

Question 15

what is the tertiary structure of a protein?

Answer 15

the further folding of a polypeptide chain into it’s 3D structure

Question 16

what bonds are present in the tertiary structure?

Answer 16

ionic
disulfide bridges
hydrophobic-hydrophilic interactions
hydrogen bonds

Question 17

in the tertiary structure what are the bonds formed between?

Answer 17

the R-groups of a protein

Question 18

ionic bonding

Answer 18

between oppositely charged R-groups

Question 19

disulfide bridges

Answer 19

between two R-groups which both contain cysteine

Question 20

hydrophobic-hydrophilic interactions

Answer 20

between hydrophobic and hydrophilic R-groups

Question 21

hydrogen bonds

Answer 21

between delta +ve and delta -ve R -groups

Question 22

what is the quarternary structure?

Answer 22

the interactions between more than one polypeptide chain

the final 3D structure

Question 23

what are the two types of protein?

Answer 23

globular
fibrous

Question 24

properties of globular proteins

Answer 24

compact
spherical
water soluble

Question 25

how are globular proteins water soluble?

Answer 25

they have their hydrophobic R-groups pointing inwards they have their hydrophilic R-groups pointing outwards

Question 26

why is water solubility important for globular proteins?

Answer 26

they have to be able to be dissolved in water to be transported

Question 27

examples of globular proteins

Answer 27

insulin haemoglobin catalase

Question 28

role of insulin

Answer 28

hormone which decreases the blood glucose level

Question 29

structure of insulin

Answer 29

two polypeptide chains joined together by disulfide bridges

Question 30

what is a conjugated protein?

Answer 30

a protein which contains a non-protein element called a prosthetic group

Question 31

example of a conjugated protein

Answer 31

haemoglobin

Question 32

what is the prosthetic group in haemoglobin?

Answer 32

Fe2+

Question 33

structure of haemoglobin

Answer 33

4 polypeptides with 2 alpha and 2 beta subunits each subunit contains a prosthetic group of Fe2+

Question 34

what does the Fe2+ do?

Answer 34

binds to oxygen or carbon dioxide which allows haemoglobin to transport it around the body

Question 35

why does haemoglobin have to be water soluble?

Answer 35

it needs to be able to dissolve in the blood to be transported around the body

Question 36

role of catalase

Answer 36

breaks down hydrogen peroxide

Question 37

structure of catalase

Answer 37

four prosthetic groups each have their own haem grou[

Question 38

properties of fibrous proteins

Answer 38

long insoluble strong - high tensile strength

Question 39

properties of fibrous proteins

Answer 39

long insoluble strong - high tensile strength

Question 40

examples of fibrous proteins

Answer 40

collagen keratin elastin

Question 41

properties of collagen

Answer 41

strong flexible insoluble

Question 42

what makes collagen strong?

Answer 42

presence of cysteine means that disulfide bridges are formed which require a lot of energy to overcome

Question 43

properties of elastin

Answer 43

flexible