Mechanics Of Biomaterials

Question 1

Engineerings tasks organs can do

Answer 1

• work in tension only
• work mainly in compression
• provide a permeable partition
• allow for fluid transport

Question 2

Composite, hierarchical materials

Answer 2

• composite: made out of several components
• hierarchical: significant structure at more than one length-scale

Question 3

Enzymes

Answer 3

• highly selective, catalysing only one reaction
• consist of a non-protein and a protein - usually globular
• catalytic activity is pH and temperature sensitive

Question 4

Cofactors, coenzymes and prosthetic groups

Answer 4

Cofactors: cations required for catalysis
Coenzymes: organic molecules, vitamins or made from vitamins, not permanently bound to enzyme molecule, activate enzyme
Prosthetic groups: organic groups (coenzymes) that are permanently bound to the enzyme

Question 5

Enzyme mechanism

Answer 5

Lock and key - induced fit - stabilises transition state

Question 6

Enzymes: how to inhibit

Answer 6

• pH and temp inhibit
• competitive inhibition or non-competitive inhibition
  Eg: ritonavir: HIV protease inhibitor
  Neviapine: HIV reverse transcriptase inhibitor

Question 7

Carbohydrates

Answer 7

• molecular compounds made from carbon, hydrogen and oxygen - polysaccharides
• source of energy for the body
• building blocks for polysaccharides

Question 8

Sugars

Answer 8

• monosaccharides
  (CH2O)n where n=3,5,6
• concentration in blood of 1 g/l
• small size and solubility in water of glucose molecules allows them to pass through cell membrane
• when metabolised energy is released

Question 9

Monosaccharides

Answer 9

• glucose, galactose, fructose
• galactose doesn’t play same part in cellular respiration
• fructose - glucose substitute

Question 10

Polysaccharides

Answer 10

Cellulose: polymer of glucose (structural)
Starch: glucose polymer (stores energy)

Question 11

Cellular respiration

Answer 11

Steps:
- glycolysis
- citric acid cycle
- electron transport chain

Question 12

Glycolysis

Answer 12

• changes glucose into puryvate
• produces 2 ATP molecules

Question 13

Citric acid cycle

Answer 13

• further oxidises puryvate to CO2
• Produces NADH and FADH2
• birth intermediates to gain more ATP

Question 14

Electron transport chain

Answer 14

-NADH and e- used to pump protons across a membrane
-ATP synthase uses pH gradient across the membrane to synthesise more ATP
- process produces 30/32 ATP molecules

Question 15

Anaerobic respiration

Answer 15

• without oxygen pyrrhic acid is converted in lactose or ethanol (yeast)
• only 2 ATPs produced via anaerobic routes