In this podcasts we summarize the structure and function of the four main classes of organic molecules found in living things:
1. Carbohydrates: sugars (e.g., glucose) and their polymers (e.g., starch and cellulose).
Structure:
Made of multiples of CH2O (e.g., glucose: C6H12O6)
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| Glucose, a monosaccharide (simple sugar) |
Functions:
- Energy storage and processing (e.g., glucose, starch)
- Structure (e.g., cellulose)
- Cellular recognition
2. Lipids: a group of non-polar, hydrophobic molecules.
Lipids include:
- Fats
Structure: 3 fatty acid attached to a glycerol backbone
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| An unsaturated fat composed of a glycerol backbone (left) and 3 fatty acids |
Functions: energy storage, thermal insulation, mechanical protection of some organs
- Phospholipids
Structure: glycerol backbone + 2 fatty acids + phosphate group and variable hydrophilic group
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| A phospholipid |
Functions: form the basic structure of biological membranes
- Steroids
Structure: 4 fused rings
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| Cholesterol, a steroid |
Functions: stabilize membranes (cholesterol); some are hormones (e.g., estrogen, testosterone)
3. Proteins
Structure: chains of amino acids folded into a 3-D structure
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| An amino acid. The nature of the R group varies depending on the amino acid. |
Functions: proteins are responsible for most of the work in living cells; e.g., structural support (e.g., collagen, keratin), movement (e.g., actin and myosin), transport (e.g., haemoglobin), catalysis of chemical reactions (enzymes).
4. Nucleic acids (DNA and RNA)
Structure: polymers of nucleotides; RNA is single-stranded, DNA is double-stranded due to complementary base pairing
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| A DNA nucleotide |
Functions: storage and transfer of genetic information in cells. The information contained in genes (DNA) is used to make proteins, a process that requires different types of RNA molecules.
Keywords and Quiz coming soon!
Keywords and Quiz coming soon!
