Bio – Wk 2 – Lecture 1 – 14/3/25: macromolecules (carbohydrates, Lipids, Nucleic acids)
4 large biological molecules:
Carbohydrates – sugars, starch, cellulose
Lipids – Fats/oils, phospholipids of biological membranes
Nucleic acids – DNA and RNA
Proteins – made from amino acids
Macromolecules are very large complex molecules:
- Built from multiple , repeating units added together
- Carbohydrates, nucleic acids and proteins are macromolecules.
- macromolecules are built from repeating units - Units (monomer)
- Lipids aren’t strictly macromolecules, but very important for life
Lipids: are diverse group of hydrophobic molecules:
- Are not true polymers
- Mix poorly with water (if at all) – insoluble in water
- Are mostly hydrogen and carbon
Types:
- Fats and oils (triglycerides)
- Phospholipids
- Steroids
Fats:
- Formed from two types of smaller molecules -> 1
glycerol (3 carbons) +
- 3 fatty acid molecules (long hydrocarbon tails – don’t
mix with water – different fatty acids have different
tail lengths)
- Unsaturated fatty acid has at least 1 or more double
bonds between carbons – saturated has no double
bonds (bound to as many hydrogens as possible)
Phospholipids:
- In a phospholipid, two fatty acids and a phosphate
group are attached to glycerol.
- The two fatty acid tails are
hydrophobic, but the phosphate
group ands it’s attachments form
a hydrophilic head.
- -phospholipids self-assemble into
double-layered sheets (bilayer)
- This is the fundamental structure
of cell membranes
- The hydrophobic tails pack tightly
together away from the aqueous
environment.
Steroids:
- Steroids are lipids characterised by four carbon rings
4 large biological molecules:
Carbohydrates – sugars, starch, cellulose
Lipids – Fats/oils, phospholipids of biological membranes
Nucleic acids – DNA and RNA
Proteins – made from amino acids
Macromolecules are very large complex molecules:
- Built from multiple , repeating units added together
- Carbohydrates, nucleic acids and proteins are macromolecules.
- macromolecules are built from repeating units - Units (monomer)
- Lipids aren’t strictly macromolecules, but very important for life
Lipids: are diverse group of hydrophobic molecules:
- Are not true polymers
- Mix poorly with water (if at all) – insoluble in water
- Are mostly hydrogen and carbon
Types:
- Fats and oils (triglycerides)
- Phospholipids
- Steroids
Fats:
- Formed from two types of smaller molecules -> 1
glycerol (3 carbons) +
- 3 fatty acid molecules (long hydrocarbon tails – don’t
mix with water – different fatty acids have different
tail lengths)
- Unsaturated fatty acid has at least 1 or more double
bonds between carbons – saturated has no double
bonds (bound to as many hydrogens as possible)
Phospholipids:
- In a phospholipid, two fatty acids and a phosphate
group are attached to glycerol.
- The two fatty acid tails are
hydrophobic, but the phosphate
group ands it’s attachments form
a hydrophilic head.
- -phospholipids self-assemble into
double-layered sheets (bilayer)
- This is the fundamental structure
of cell membranes
- The hydrophobic tails pack tightly
together away from the aqueous
environment.
Steroids:
- Steroids are lipids characterised by four carbon rings
