Molecular Biology
Field of study that focuses on investigating biological activity at a molecular level
Compare and contrast the reductionist and systems to approach to molecular biology
reductionism studies the individual components of a biological system in isolation
systems biology aims to study the parts of a system when they are part of a whole
How many bonds can carbon form ?
Four single bonds
or
Two double bonds
Carbon has four electrons in their valence shell
What properties of carbon allows it to form a diversity of stable compounds
Ability to form covalent bonds, stable molecules can be formed.
Stability allows carbon to form large molecules
The four major groups of carbon compounds used by organisms
Carbohydrates, Lipids, proteins and nucleic acid
state the elements contained in carbohydrates and outline the basic properties and give examples
Carbon, hydrogen and oxygen
Functions
- source of energy
- production of ATP in cells
- Long term storage in plants
- Build cell wall in plants
- component of DNA/RNA
Examples
- Bread
- Pasta
state the elements contained in Lipids and outline the basic properties and give examples
Carbon, oxygen and hydrogen
1 glycerol and three fatty acids - triglycerides
Properties
- Non polar
- major component of cell membranes (phospholipid and cholesterol)
- Long term energy storage molecule
- Signalling molecules (steroids)
Examples
- Avocado
- Seeds and nuts
- Eggs
- meat
state the elements contained in Proteins and outline the basic properties and give examples
Carbon, hydrogen, oxygen and nitrogen (sulphur is present in some
Properties
- made of amino acids arranged in chains
- metabolic proteins acts as catalysts
- structural molecules
- Cellular signalling, transduction pathways
Examples
- Polypeptides
- Milk
- Yoghurt
- Cheese
- Dairy products
- Fish
state the elements contained in Nucleic acid and outline the basic properties and give examples
Carbon, hydrogen, oxygen, nitrogen, phosphorus chains of subunits called nucleotides - consist of base sugar - phosphate group covalently bonded together
Ribose -> RNA
Deoxyribose –> DNA
Properties
- store genetic info
- create proteins at ribosome using info stored in DNA
Define metabolism
the web of all enzyme-catalysed reactions that occur within a cell or organism
pathways by which one type of molecule is transformed into another
Define Anabolism
synthesis of complex molecules from simpler molecules
including the formation of macromolecules from monomers by condensation reactions
Explain Condensation reaction
two smaller organic molecules combine to form a larger molecule whilst forming water or some other simple molecule
water releasing, formation of bonds
Examples of Anabolism
Protein synthesis
DNA synthesis
Photosynthesis
Synthesis of complex carbohydrates
Define Catabolism
Breakdown of complex molecules into simple molecules including the hydrolysis of macromolecules into monomers
release energy
Explain Hydrolysis reaction
breaking of chemical bonds by the addition of water molecules
Examples of Catabolism
Digestion of food in the mouth, stomach and small intestine
Cell respiration
Digestion of complex carbon compounds in dead organic matter ny decomposers
What is Urea
an example of an organic compound that can be artificially synthesised
Define Vitalism
organic molecules could only be synthesized by living systems
people believed that living things has this “vital force” which makes organic molecules
Falsification of vitalism
- In 1828, Frederick Woehler heated an inorganic salt (ammonium cyanate) and produced urea
- Urea is a waste product of nitrogen metabolism and is eliminated by the kidneys in mammals
- The artificial synthesis of urea demonstrates that organic molecules are not fundamentally different to inorganic molecules
