Globular Proteins

Question 1

What are globular proteins?

Answer 1

• Soluble in water
• Spherical because non-polar hydrophobic R groups orientate towards centre, and polar hydrophilic R groups orientate themselves to outside
• Can be easily transported in organisms and used in metabolic reactions
• Some conjugated and contain prosthetic groups like haemoglobin

Question 2

Bio Molecules notes on haemoglobin

Answer 2

• Globular
• Carries 4 oxygen molecules
• Quaternary structure, 4 subunits, 2 alpha 2 beta chains
• Contains a prosthetic haem group (Fe 2+, can reversibly combine with oxygen)
• Sickle cell anaemia is where sequence of amino acids is changed in haemoglobin

Question 3

Catalase function

Answer 3

• Intracellular
• Hydrogen peroxide biproduct of metabolic reactions
• Harmful to cells
• Catalase converts H2O2 to water and oxygen
• Prevents damage to cells

Question 4

Amylase function

Answer 4

• Extracellular
• Amylase hydrolyses starch into simple sugars
• Secreted by salivary glands and pancreas
• Digests in mouth and small intestine