3. Proteins

Question 1

proteins are made up of

Answer 1

1 or more polypeptide

Question 2

a polypeptide is formed when more than 1

Answer 2

amino acids join together

Question 3

general structure of amino acids

Answer 3

carboxyl group COOH
amine group NH2
carbon containing R group (variable

Question 4

all living things share

Answer 4

20 amino acids

Question 5

only difference between amino acids is what makes up the

Answer 5

carbon containing R group

Question 6

bonds between amino acids are

Answer 6

peptide bonds

Question 7

amino acids are linked together by

Answer 7

condensation reaction (H2O released)

Question 8

primary structure

Answer 8

sequence of amino acids in the polypeptide chain

Question 9

secondary structure

Answer 9

H bonds form between amino acids

makes it coil or fold

Question 10

tertiary structure

Answer 10

coiled and folded further
more bonds between different parts of the polypeptide chain - hydrogen bonds, ionic bonds and disulfide bridges
for proteins made of a single polypeptide chain this forms their final 3d structure

Question 11

quatenary structure

Answer 11

several polypeptide chains held together by bonds

quatenary structure is the way these polypeptide chains
are assembled together

for proteins made of more than one polypeptide chain e.g. haemoglobin quatenary structure is the proteins final 3D structure

Question 12

proteins as enzymes

Answer 12

soluble
often have roles in metabolism
e.g. some enzymes break down large molecules and others help to synthesis large molecules

Question 13

proteins as antibodies

Answer 13

immune reponse 
2 light (short) polypeptide chains and 2 heavy (long) polypeptide chains 
variable regions

Question 14

proteins as transport proteins

Answer 14

transport molecules and ions across membranes

Question 15

proteins as structural proteins

Answer 15

physically strong
long polypeptide chains parallel to each other with cross-links between them
keratin (found in hair and nails)
collagen (found in connective tissue)

Question 16

test for proteins

Answer 16

biuret test
1. test solutuion needs to be alkaline so add few drops of sodium hydroxide solution
2. add some copper (II) sulfate solution.
protein present = purple
no protein = stays blue