L4 - Proteins p1

Question 1

How many natural amino acids are there?

Answer 1

20

Question 2

what are examples of proteins?

6

Answer 2

enzymes, hormones, haemoglobin, collagen

actid, myosin (in muscles)

Question 3

what type of bond do proteins have?

Answer 3

peptide bonds

Question 4

what are essential amino acids?

Answer 4

amino acids that must be obtained from diet

can’t be made in body

Question 5

what are some properties of amino acids?

3

Answer 5

colourless

crystalline

genuinely soluble in water but insoluble in organic solvents

Question 6

What test is done for proteins?

Answer 6

biuret test

Question 7

What is the biuret test?

Answer 7

add 2-3cm of liquid food sample to a clean, dry test tube

add 2-3cm of biuret reagent

observe for colour change

blue - purple/lilac means protein is positive

Question 8

What is the structure of an amino acid?

5

Answer 8

1 amino group (2H, 1N)

1 carboxylic acid group (1C, 10, 1OH)

1 R group

1 C in middle

1H off the C

Question 9

What are proteins made of?

Answer 9

amino acids

Question 10

What are the 4 levels of structure for protein?

Answer 10

primary
secondary
tertiary
quaternary

Question 11

What makes up amino acids?

Answer 11

carbon, hydrogen, oxygen, nitrogen