1.6 Proteins

Question 1

List 3 examples of proteins

Answer 1

• enzymes
• channel proteins
• transport proteins

Question 2

What is the function of enzymes?

Answer 2

• roughly spherical in shape due to tight folding of polypeptide chains
• soluble
• have roles in metabolism like digestives enzymes
• some help to synthesise (make) large molecules

Question 3

What is the function of a transport enzyme?

Answer 3

• channel proteins
• they’re in membranes - - hydrophobic and hydrophilic amino acids
• these amino acids cause the protein to fold up into a channel
• these proteins transport molecules and ions across the membrane

Question 4

What is the function of a structural protein

Answer 4

• physically strong
• consist of long polypeptide chains lying parallel to each other with cross links
• eg keratin and collagen

Question 5

What is the test for proteins and the positive result?

Answer 5

• solution needs to be alkaline so add sodium hydroxide solution
• add copper (II) sulfate solution
• protein is present = purple solution