HS2339 Week 1 Organic Material Structure and Properties

Question 1

Describe the two main categories of organic materials

Answer 1

Question 2

Leather- preparatory process

Answer 2

preparatory process prevents putrefaction
protein based

Question 3

Explain the fibrous nature of leather

Answer 3

• leather is built up from many polymer chains
• amino acids react orderly to create long patterns of side chains attached to amino acids
• preferred order is twisting into a helix, rope like structure
• ## align to produce fibrils, hence fibrous structure of leather

Question 4

Explain the effect of water on leather

Answer 4

• water swells leather, attracted through hydrogen bonds onto OH group on proteins

Question 5

Physical structure of wood and plant cells (diagrams)

Answer 5

• because of the hydrogen bonding abilities of cellulose
  attracts moisture from the atmosphere and will expand or contract the cellulose depending on hydrogen bonding
• leads to paint layers peeling off wood with expansion and contraction

Question 6

Describe how wood cracks due to it being anisotropic

Answer 6

• anisotropy, does not have the same properties in both directions
• when they absorb water, they swell differently along both axises
• leads to breaking/ cracking

Question 7

Cell wall chemistry in plants

Answer 7

• polymeric, based on cellulose

Question 8

describe biodeteriation

Answer 8

• we can use chemicals to hydrolyse and break down chains in both cellulose and proteins ie wood and leather
• normally in nature, broken down by microbes in biodeteration
• ## microbe utilise cellulose and protein for food, break down structure through hydrolysis. bodily process