2.1 Molecules to metabolism

Urea

Urea

A nitrogen-containing compound that can be naturally produced in urine or artificially synthesized

Purpose of urea

Produced when there is an excess of amino acids in the body as to excrete the nitrogen from the amino acids

Natural synthesis of urea

Produced in the liver and then transported by the bloodstream to the kidneys, where it is filtered and passed out of the body in urine

Vitalism

Theory that the origin and phenomena of life are due to a vital principle, different from purely chemical or physical forces, that is only present in living organisms

Falsification of vitalsim

In 1828, German chemist Wohler synthesized urea using silver isocyanate and ammonium chloride, the first artificial synthesis of a compound

Carbohydrates

Molecules composed of C, H, and O. H and O in a 2:! ratio

Lipids

Broad class of molecules that are insoluble in water. Includes fatty acids, triglycerides, steroids and waxes

Proteins

Molecules composed of one or more chains of amino acids (contains C, H, O, and N)

Nucleic acids

Chains of subunits called nucleotides (containing C, H, O, N and P)

Types of nucleic acids

Ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)

Drawing ribose

• formula: C5H10O5

• 5-membered ring with a side chain

• C1 on the right of oxygen

• -OH up in C1, down in C2 and C3

Drawing glucose

• formula: C6H12O6

• 6-membered ring with a side chain

• C1 on the right of oxygen

• -OH down in C1, C2 and C4, up in C3

Drawing amino acids

• carbon in the centre is bonded to

• amine group -NH2

• carboxyl group -COOH

• H

• R group

Drawing fatty acids

• C-atoms form an unbranched chain

• Bonded to each other by single bonds

• At one end is part of a carboxyl group

• At the other end the C-atom is bonded to three H atoms

• All other C atoms are bonded to 2 H atoms  

Metabolism

the sum of all the enzyme-catalyzed reactions in a cell or organism

Metabolic pathways

Process in which one type of molecule is transformed into another in a series of small steps

Anabolism

Synthesis of simpler molecules into complex molecules. Requires energy, usually as ATP

Anabolic processes

• Condensation reactions

• Protein synthesis using ribosomes

• DNA synthesis during replication

• Photosynthesis

• Synthesis of complex carbohydrates

Catabolism

Breakdown of complex molecules into simpler molecules. Releases energy (due to breaking of bonds)

Catabolic processes

• Hydrolysis

• Digestion of food

• Cell respiration

• Digestion of complex carbon compounds in dead organic matter by decomposers