Protein functional diversity

Question 1

Characteristics of globular proteins?

Answer 1

• functional
• water soluble
• usually spherical - tertiary structure critical to function
• weaker

Question 2

Characteristics of fibrous proteins

Answer 2

• structural
• not water solube
• elongated
• stronger, and more beta pleated sheets

Question 3

Why are proteins functionally diverse?

Answer 3

many combinations of amino acids are possible. This can form many proteins with diverse structures, and therefore functions.

Question 4

7 main types of proteins?

Answer 4

SHIT CRE(E)
Structural - fibrous support tissue in skin, bone (collagen/keratin)
Hormone - regulates body acivities (insulin)
Immunoglobulin - defence against disease (antibodies)
Transport - carries other molecules (haemoglobin)
Contractile proteins - facilitate muscle movement (myosin)
Receptor molecule - responds to stimuli (eg. insulin receptors)
Enzyme - catalyses reactions (lactase)

Question 5

why are globular proteins water soluble and fibrous proteins not?

Answer 5

in globular proteins, amino acids with polar side chains tend to point outwards - they can interact with water and dissolve . Fibrous -> inwards -> can’t interact