Proteins

Question 1

What are proteins and how are they formed?

Answer 1

Naturally condensation polymers formed by joining together thousands of amino acid molecules.

Question 2

What are amino acids functional groups?

Answer 2

• Amino (amine) group -NH2
• Carboxyl group -COOH

Question 3

What are essential amino acids?

Answer 3

Amino acids which must be present in a humans diet at the cannot be synthesised by the body

Question 4

How do you make proteins?

Answer 4

The condensation of amino acids

Question 5

How do you break proteins?

Answer 5

Through hydrolysis

Question 6

Describe the process of breaking down proteins into amino acids?

Answer 6

Water molecules break apart the peptide links of the protein molecule (hydrolysis) leaving amino acids

Question 7

What is the amide/peptide link?

Answer 7

H O
| ||
— N—C —

Question 8

What are the 2 main types of protein molecules?

Answer 8

Fibrous & Globular

Question 9

Where are fibrous proteins found?

Answer 9

Animal tissue, hair, nails, muscle

Question 10

Properties of fibrous proteins?

Answer 10

They are long, spiral chains folded to for long thin shapes.
They are strong and generally insoluable in water

Question 11

Properties of Globular proteins?

Answer 11

They are spiral chains folded into spherical shapes held by intermolecular bonding between the side chains of the amino acids involved.
Generally soluble in water.

Question 12

Where are Globular proteins found?

Answer 12

Haemoglobin and certain hormones like insulin and enzymes

Question 13

What does cooking proteins allow?

Answer 13

For the proteins to denature (change shape) which changes the texture of foods.

Question 14

Hydrophilic meaning

Answer 14

Soluable/mixes with water - likes water

Question 15

Hydrophobic meaning

Answer 15

Insoluable/ does not mix with water - dislikes water

Question 16

What happens when you heat a protein?

Answer 16

It denatures - breaking the hydrogen bonds and resulting in a change in shape