List the 6 nutrients required for all organisms. Describe their role briefly.
- Carbohydrates (including fibre for humans): Energy storage & supply, structure (in some organisms).
- Proteins: Structure, transport (membranes), enzymes, antibodies, most hormones.
- Lipids: Membranes, energy supply, thermal & electrical insulation, protective layer/padding, some hormones.
- Vitamins and minerals: Form parts of some larger molecules, take part in some metabolic reactions, some act as coenzymes or enzyme activators.
- Nucleic acids: Information molecules - carry instructions for life.
- Water: Take part in many reactions, support in plants, solvent for most metabolic reactions, transport.
List the 4 key biological molecules.
- Nucleic acids
What is a risk factor?
A factor that increase your chance of developing a particular disease.
The main chemical elements found in biological molecules are:
- (These elements make up 99% of all organisms)
The sum total of all the biochemical reactions taking place in the cells of an organism.
What does biochemistry refer to?
Biochemistry refers to the chemical reactions involving biological molecules.
What is the name for a metabolic reaction involved in breaking larger molecules into smaller ones? Give 1 example.
- Catabolic reactions
- eg. digestion
What is the name for metabolic reactions involving building smaller molecules into larger ones? Give 1 example.
- Anabolic reactions
- eg. muscle growth.
Carbon has a valency of 4. What does this mean?
- Means it can form covalent bonds with 4 other atoms.
- It can bond together to form long chains and rings, and possible to bond other atoms to these. Because of this multi-bonding feature, carbon is a kind of framework atom.
Which types of biological molecules can form polymers?
- Carbohydrates, Proteins, Nucleic acids
- (Lipids are made of smaller molecules bonded together, they are not polymers because the smaller molecules are very different from each other.)
What is the monomer and polymer of carbohydrates?
- Monomer - Monosaccharides (simple sugars)
- Polymer - Polysaccharides
What is the monomer and polymer of proteins?
- Monomer - Amino acids
- Polymer - Polypeptides and proteins
What is the monomer and polymer of nucleic acids?
- Monomer - Nucleotides
- Polymer - DNA and RNA
What is the chemical reaction that links biological monomers together called? What does it also combine?
- Condensation reaction
- (same reaction is repeated many times to link many monomers together to form polymer)
- It also links the different subunits together in lipid molecules.
What happens in condensation reactions?
- A water molecule is released
- A new covalent bond is formed
- A larger molecule is formed by the bonding together of smaller molecules
What is the name of the reaction that splits larger molecules to monomers?
- Hydrolysis reaction
- (reverse of condensation)
What happens in all hydrolysis reactions?
- A water molecule is used
- A covalent bond is broken
- Smaller molecules are formed by the splitting of a larger molecule
Hydrogen bonds occur between what?
- Form when a slightly negatively charged part of a molecule comes close to a slightly positively charged hydrogen atom in the same (or another0 molecule. eg. in water.
- They are not strong bonds - can be easily broken (by heating for example) and often described as "interactions" or "forces".