Protiens

Question 1

what does organic mean?

Answer 1

Containing carbon

Question 2

what are the roles of protiens

Answer 2

-structural
-metabolic
-transport

Question 3

what elements do amino acids contain

Answer 3

carbon, hydrogen, oxygen, nitrogen and sometimes sulphur and phosphate

Question 4

Polymer of amino acid

Answer 4

Polypeptide

Question 5

Carboxyl/acid group

Answer 5

c=0
-oh

Question 6

amino group

Answer 6

N-h
-h

Question 7

What’s an R group

Answer 7

-variable group

Question 8

how many amino acids are there?

Answer 8

20, 8 essential ones

Question 9

what does essential mean

Answer 9

must get them in our diet

Question 10

properties of amino acids

Answer 10

-they’re soluble
-they’re amphoteric

Question 11

how amino acids differ

Answer 11

-size
-polarity
-charge

Question 12

what are the positive and negative amino acids called

Answer 12

positive- base
negative- acid

Question 13

how do amino acids join together

Answer 13

join by a reaction between amino group of one protein and carboxyl group of the other amino acid
-this is a condensation reaction

Question 14

bond/link between amino acids

Answer 14

peptide link/bonds

Question 15

similarity and difference between glyosidic bond and peptide bond

Answer 15

similarity- condensation build up and hydrolysis breaks down
difference- peptide has link between C-N and glyosidic bond between
C-O-C

Question 16

amphoteric

Answer 16

amino group accepts H+ ions and carboxylic group donates H+ ions
-in acidic environment, amine accepts H+
-in alkaline environment, carboxyl/acid group donates H+

Question 17

primary structure

Answer 17

specific sequence of amino aicds- one long chain, coded by the DNA of the cell

Question 18

secondary structure

Answer 18

form when polypeptide chain takes up a particular shape through folding

Question 19

forms of secondary structure

Answer 19

alpha helix and beta sheet

Question 20

how is alpha helix and beta pleated sheet formed

Answer 20

hydrogen bonds between hydrogen of amine and oxygen of carboxyl

Question 21

tertiary structure

Answer 21

secondary structure folded further to form complex shape due to 4 different bonds between acids

Question 22

4 types of bond in tertiary protiens

Answer 22

Disulphide, ionic, hydrogen, hydrophilic/phobic interactions

Question 23

hydrogen bonds

Answer 23

form between hydrogen atoms with slight positive charge and other atoms with a slight negative charge
-amino and carboxyl group
-give protein strength

Question 24

ionic bonds

Answer 24

between carboxyl and amino groups that are part of R groups, positive and negative groups strongly attracted to each other

Question 25

disulphide links

Answer 25

-the R group of amino acid cysteine contains sulphur -disulphide bridges formed between the R groups of two cysteines, strong covalent bonds

Question 26

hydrophobic and hydrophilic interactions

Answer 26

-hydrophobic parts of R groups associate together in centre of polypeptide in water (rotate inwards) -hydrophilic parts associate with each other on the edge of the polypeptide to be close to water (turn outwards)

Question 27

quaternary structure

Answer 27

more than one polypeptide chain, arranged in a complex structure

Question 28

example of quaternary protein and its structure

Answer 28

Haemoglobin, contains the haem group which bonds to the o2 and polypeptide chains

Question 29

strong to weakest bonds

Answer 29

ionic, disulphide, hydrogen

Question 30

properties of fiberous proteins

Answer 30

-mostly insoluble -not folded into a complex 3D shape -strong, long molecules -have high proportion of amino acids with hydrophobic R groups -repetative AA sequence in primary structure creates organised structure, compact

Question 31

properties of globular proteins

Answer 31

-folded to keep hydrophobic R groups inside and hydrophillic R groups outside -soluble in water -spherical in shape -must be soluble for processes such as chemical reactions, immunity and muscle contraction

Question 32

example of globular protein

Answer 32

insulin- transported in blood so must be soluble

Question 33

example of fiberous protein

Answer 33

-keratin and elastin

Question 34

structure of heamaglobin

Answer 34

globular, quaternary protein with 4 subunits, 2 alpha globin and 2 beta globin chains- each subunit has one haem that has iron which binds to oxygen

Question 35

denaturisation of proteins

Answer 35

-typically effect secondary , tertiary or quintenary structures but doesn't affect peptide bonds in primary structure

Question 36

features of primary structure

Answer 36

-sequence of AA's -peptide bonds

Question 37

features of secondary structure

Answer 37

-hydrogen bonds -initial folding of protein chain -alpha helices and beta pleated sheets

Question 38

features of tertiary structure

Answer 38

-overall 3D shape begins to form -ionic bonding

Question 39

features of quaternary structure

Answer 39

-alpha and beta subunits -prosthetic groups -multiple chains