2.1 Molecules to metabolism Flashcards
Organic compounds
A compound that contains carbon and is found in living things.
Carbon
- Atomic number 6, which means that it has 4 electrons in its outer shell.
- These can form 4 covalent bonds with other carbon atoms or atoms of other elements, allowing a diversity of stable carbon compounds to exist.
Covalent bonds are the strongest type of bonds between atoms.
Carbon based compounds found in living organisms include:
- Carbohydrates
- Lipids
- Proteins
- Nucleic acids
These are the 4 types of macromolecules
Skill: Drawing molecular diagrams of glucose, ribose, a saturated fatty acid and a generalized amino acid.
Carbohydrates
- Composed of CHO
- The ratio of hydrogen to oxygen is 2:1
- Glucose is the monomer of carbohydrates
- (CH2O)n
- Monomers are commonly ring shaped molecules
Learn to draw alpha-d-glucose and beta-d-glucose!
Alpha-D-glucose
Carbohydrate - common monosacchirade
Used in the production of ATP in cells.
Beta-D-glucose
Carbohydrate - common monosacchirade
Used to build cell walls in plants (makes cellulose)
Starch
Carbohydrate
Used as long term storage in plants.
- Made of alpha-D-glucose
Ribose
Carbohydrate - common monosacchirade
Used as a component of RNA and DNA.
Lipids
- Made of CHO
- Non-polar, hydrophobic molecules
- Serve as a major component in cell membranes (phospholipids, cholesterol)
- May be utilised as a long-term energy storage molecule (fats and oils)
- Also may function as a signaling molecule (steroids)
- The monomers of lipids are fatty acids and glycerol
Triglycerides
Lipid
Used as long term storage in adipose tissue (body fat) in animals
Made of one glycerol molecule and three fatty acids
Steroids
Lipid
Used as chemical messengers in the body.
- Have a distinct ring shape.
Phospholipids
Lipid
Major component in plasma membranes.
Proteins
- Composed of CHON (sometimes they also contain S)
- Consists of amino acids that are arranged in long chains (joined by peptide bonds)
Uses of proteins
- Structural proteins - keratin, collagen
- Enzymes - catalase
- Hormones - insulin
- Immunoglobin - antibodies
- Gas transport - haemoglobin
Nucleic acids
- Composed of CHONP
- Chains formed by nucleotides
- Nucleotides are formed of a nitrogenous base, a pentose sugar and a phosphate group
- If the sugar is ribose, the nucleic acid formed will be RNA. If the sugar is deoxyribose then DNA is formed.
- DNA: used to store genetic information.
- RNA: used to create proteins at ribosomes using the information stored in DNA
Metabolism
Metabolism is all of the enzymatic reactions that take place in a cell or organism.
anabolism + catabolism
Anabolism
- The synthesis of complex molecules from simpler molecules
- The formation of macromolecules from monomers by condensation reaction
- Requires the input of energy
- Example: protein made form amino acids, starch made from glucose units
Condensation reaction
Anabolism
The reaction in which two smaller organic molecules combine to form a larger molecule with the accompanied formation of water (or some other simple molecule).
Catabolism
- The breakdown of complex molecules into simpler molecules
- Includes the hydrolysis of macromolecules into monomers
- Releases energy
- Example: the breakdown of sugars (including glycolysis) and fats to release energy
Hydrolysis reaction
Catabolism
The breaking of chemical bonds by the addition of water molecules.
Vitalism
A doctrine that dictated that organic molecules could only be synthesised by living systems.
- Not from inorganic molecules.
Urea
- Wöhler accidentally synthesised urea in 1828, whilst attempting to prepare ammonium cyanate.
- He demonstrated that a by-product of life could be artificially synthesised in a laboratory.
- This undermines vitalism as organic chemicals were previously thought to by synthesised only by organisms.
Polymers containing glucose
Starch, glycogen, amylose, amylopectin
