Skill:
• Identification of biochemicals such as sugars, lipids or amino acids from molecular diagrams
Carbohydrates
The structure of complex carbohydrates may vary depending on the composition of monomeric subunits
Polysaccharides may differ according to the type of monosaccharide they possess and the way the subunits bond together
- Glucose monomers can be combined to form a variety of different polymers – including glycogen, cellulose and starch
Polymers of Glucose
Lipids
Lipids can be roughly organised into one of three main classes:
- Simple (neutral) lipids – Esters of fatty acids and alcohol (e.g. triglycerides and waxes)
- Compound lipids – Esters of fatty acids, alcohol and additional groups (e.g. phospholipids and glycolipids)
- Derived lipids – Substances derived from simple or compound lipids (e.g. steroids and carotenoids)
Three Main Types of Lipids
Proteins
Amino acids join together by peptide bonds which form between the amine and carboxyl groups of adjacent amino acids
The fusion of two amino acids creates a dipeptide, with further additions resulting in the formation of a polypeptide chain
- The subsequent folding of the chain depends on the order of amino acids in a sequence (based on chemical properties)
Formation of a Dipeptide
Nucleic Acids
Nucleotides form bonds between the pentose sugar and phosphate group to form long polynucleotide chains
- In DNA, two complementary chains will pair up via hydrogen bonding between nitrogenous bases to form double strands
- This double stranded molecule may then twist to form a double helical arrangement
Formation of a Polynucleotide Chain
