proteins

Question 1

proteins:
what’s the polymers?
what’s the monomers?

Answer 1

monomers- amino acids
polymers- proteins

Question 2

what are the chemical elements in proteins.

Answer 2

C H O N (S)

Question 3

what’s a dipeptide?
what’s a polypeptide?

Answer 3

dipeptide- 2 amino acids joined together
polypeptide- 2+ amino acids joined together

Question 4

what are proteins made up of?

Answer 4

one or more polypeptides

Question 5

what’s the general structure of an amino acid

Answer 5

R group, carbon, hydrogen, amino group, carboxyl group
textbook pg 59

Question 6

what bond joins amino acids?

Answer 6

peptide bond

Question 7

what reaction joins amino acids?

Answer 7

synthesis:
condensation
OH+H forms a molecule of water - carboxyl and amine interact

Question 8

how are peptide bonds broken?

Answer 8

hydrolysis
adding molecule of water
assisted by protease (enzyme)

Question 9

what are the levels of protein structure?

Answer 9

primary
secondary
tertiary
quaternary

Question 10

what is the primary structure?

Answer 10

• sequence of amino acids in the poly peptide chain

Question 11

what is in the secondary structure?

Answer 11

• the hydrogen bonds forming between nearby amino acids in the chain
• making it coil into an alpha helix or a beat pleated sheet

Question 12

what’s in the tertiary structure?

Answer 12

-the further folding or coiling of the amino acids -> from the secondary structure bring R groups of different amino acids closer together so more interactions and bonds form
-if it’s a single polypeptide chain this is their final 3D structure

Question 13

what’s in the quaternary structure?

Answer 13

-how multiple different polypeptide chains (subunits) are assembled together

eg insulin is made of 2 bonded together poly peptide chains
eg haemoglobin is made of 4 bonded together polypeptide chains

-proteins with more than 1 polypeptide chain this is the proteins final 3D structure

Question 14

what type of bonding is holding the primary structure of the protein together?

Answer 14

peptide bonds between amino acids

Question 15

what type of bonding is holding the secondary structure of the protein together?

Answer 15

hydrogen bonds between nearby amino acids in the chain

Question 16

what type of bonding is holding the tertiary structure of the protein together(describe)? [4]

Answer 16

• ionic bonds- between oppositely charged R groups
• disulfide bonds/bridges- covalent, between R groups containing sulfur atoms
• hydrogen bonds- between same slightly charged atoms in R groups on polypeptide chain

•hydrophobic+hydrophilic interactions-hydrophobic R groups interact and clump together so hydrophilic R groups are pushed to the outside. affects folds in final structure

Question 17

what type of bonding is holding the quaternary structure of the protein together?

Answer 17

determined by tertiary so all bonds could influence

Question 18

order the bonds weakeast to strongest in the tertiary structure.

Answer 18

weakest: hydrophobic/philic interactions
hydrogen
ionic
strongest: disulfide

Question 19

what are the named types of protein? [3]

Answer 19

• globular -> conjugated
• fibrous

Question 20

what’s the structure of a globular protein?

Answer 20

hydrophilic R groups on amino acids pushed to outside of protein, caused by the folds from hydrophobic and hydrophilic interactions in tertiary structure

Question 21

what’s the example of a globular protein?

Answer 21

insulin

Question 22

what’s the example of a globular protein?

Answer 22

insulin

Question 23

what’s insulin?

Answer 23

hormone released by pancreas, into bloodstream
helps regulate blood glucose concentration

Question 24

what’s the structure of insulin?

Answer 24

2 poly peptide chains, held together by disulfide bond

Question 25

what’s the properties of globular proteins?

Answer 25

soluble
- so insulin can be transported into the blood stream for blood glucose conc
+ to regulate other chemical reactions, muscle contraction, immunity ect

Question 26

what’s structure of a conjugated protein?
example

Answer 26

globular proteins with a prosthetic group-eg haem containing ion Fe2+

haemoglobin
catalase

Question 27

what is haemoglobin?

Answer 27

• red, oxygen carrying pigment in red blood cells

Question 28

what is the structure of haemoglobin?
what does it allow?

Answer 28

• quaternary protein made of 4 polypeptides: 2 alpha, 2 alpha
• the ion Fe2+ allows each subunit containing prosthetic haem group, can combine to oxygen molecule so oxygen can be transported around the body

Question 29

what is catalase?

Answer 29

enzyme, catalyses reactions, increasing reaction rate

Question 30

what is the structure of catalase?
what does it allow?

Answer 30

-quaternary protein containing 4 haem prosthetic groups with Fe2+ ions inside.
-allows catalase to interact with hydrogen peroxide and speed up its breakdown.
- to stop it damaging cell components

Question 31

what is are fibrous proteins?
what are their properties? [3]

Answer 31

structural proteins

1) insoluble
2) strong
3) fairly unreactive

Question 32

what are the examples of fibrous proteins? [3]

Answer 32

keratin
elastin
collagen

Question 33

what is keratin?

Answer 33

fibrous proteins:
in external structures of animals
eg. skin, hair, nails, feathers, horns
flexible (skin) or hard/tough (nails)

Question 34

what is elastin?

Answer 34

fibrous proteins:
- elastic connective tissue
eg. skin, large blood vessels, ligaments
- elastic, tissues can return to original shape after stretched

Question 35

what is collagen?

Answer 35

fibrous protein:
- in animal collective tissues
eg bone, skin, muscle, NS, tendons, ligaments
- minerals can bind to them to increase rigidity, long, strong