Metabolic Molecules (2.1)

Question 1

What is an organic compound?

Answer 1

A compound that contains carbon and is found in living things.

Question 2

Why does carbon form the basis of organic life?

Answer 2

Because each carbon atoms forms four covalent bonds allowing a great diversity of compounds to exist. These covalent bonds are relatively strong so the molecules formed are stable.

Question 3

Important carbon compounds

Answer 3

Carbohydrates, lipids, proteins and nucleic acids.

Question 4

What are the three groups of carbohydrates?

Answer 4

Monosaccharides (single sugar units)
Disaccharides (two sugar units)
Polysaccharides (many sugar units)

Question 5

What are lipids made up of?

Answer 5

Lipids exist in many different structures so do not have a recurring monomer. However, many lipids contain fatty acid chains as part of their structure. Fatty acid chains are long chains of hydrocarbons that can be saturated or unsaturated.

Question 6

What are proteins made up of?

Answer 6

Monomers called amino acids, which join together to form polypeptide chains.

Question 7

What are nucleic acids made up of?

Answer 7

Monomers called nucleotides, which join together to form polynucleotide chains. Nucleotides are made up of a pentose sugar, a phosphate group and a nitrogenous base.

Question 8

Theory of Vitalism

Answer 8

The idea that living organisms were composed of organic molecules that could only be produced by a ‘vital force’.

Question 9

How was the Theory of Vitalism falsified?

Answer 9

The synthesis of Urea by Fredrich Wohler in 1828.

Question 10

Explain the synthesis of Urea

Answer 10

Urea is produced naturally in human urine but Wohler synthesised Urea using silver isocyanate and ammonium chloride.

Question 11

Metabolism

Answer 11

The web of all enzyme-catalysed reactions that occur within a cell or organism.

Question 12

What functions does metabolism serve?

Answer 12

1) A source of energy for cellular processes like growth.
2) Enables the synthesis of new materials for use within the cell.

Question 13

What is a metabolic pathway?

Answer 13

A series of chemical reactions within a cell.

Question 14

What is anabolism?

Answer 14

The synthesis of complex molecules from simpler molecules. Typically occurs via condensation reactions.
Example: The synthesis of glucose from CO2 in photosynthesis

Question 15

What is catabolism?

Answer 15

The breakdown of complex molecules into simpler molecules. Typically occurs via hydrolysis reactions.
Example: The breakdown of glucose into CO2 and H2O in respiration.