B1.1 - carbon, condensation and carbohydrates (2c)

Question 1

what is an organic molecule?

Answer 1

any molecule that contains a C-C or C-H bond

Question 2

why is carbon the basis for life?

Answer 2

carbon is the basis of life due to bonding properties as it can form 4 single bonds with other carbon atoms or non-metallic compounds (H, O, N, P) in a covalent bond, where electrons are shared

Question 3

why is there great diversity of organic compounds?

Answer 3

there is great diversity of organic compounds as due to different:
categories - most molecules in living organisms are carbohydrates, lipids, proteins or nucleic acids
structures - can be branched or unbranched, single or multiple rings

Question 4

what is metabolism?

Answer 4

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

Question 5

what is anabolism?

Answer 5

the synthesis of complex molecules from simpler molecules, including the formation of macromolecules from monomers by condensation reactions

Question 6

what is catabolism?

Answer 6

the breakdown of complex molecules into simpler molecules, including the hydrolysis of macromolecules into monomers

Question 7

what are monosaccharides?

Answer 7

monosaccharides are the monomer forms of carbohydrates (simple sugas, such as glucose and fructose)
- monosaccharides have a similar number of oxygen and carbon atoms, because carbohydrates have the simplified formula CH₂O

Question 8

what are disaccharides?

Answer 8

two monosaccharides joined together
- sucrose and maltose

Question 9

what are polysaccharides?

Answer 9

glucose monomers are linked in chains, through condensation reactions, to form polymers, called polysaccharides
- many monosaccharides joined together
- e.g) starch (amylose and amylopection), glycogen and cellulose

Question 10

what are condensation reactions?

Answer 10

condensation reactions occur between two hydroxyl groups
- an -O- bond is formed between the 2 monomers
- water is released

Question 11

what are hydrolysis reactions?

Answer 11

water molecules are split to provide the -H and -OH groups that are incorporated to produce monomers

Question 12

where does hydrolysis occur in our bodies?

Answer 12

• digestion, which releases monomers from stored polysaccharides

Question 13

what is glucose?
what are the properties?

Answer 13

glucose is one of the main monosaccharides in living organisms, because its properties link well to how it is used:

• glucose is a polar molecule, due to having five hydroxyl (-OH) groups, each of which has a polar bond
• this means glucose dissolves readily in the polar solvent water
• glucose has high transportability
  it is very soluble in water and so can be transported in blood plasma and tissue fluid
• glucose is chemically stable because the bonds are covalent bonds that do not readily break
• glucose yields a lots of chemical energy when its covalent bonds are broken in oxidation reactions (ie, respiration), making it a good energy store

Question 14

what are examples of pentose monosaccharides?

Answer 14

5 C and 6 O - ribose

5 C and 5 O - deoxyribose

Question 15

what are examples of hexose monosaccharides?

Answer 15

6 C and 6 O atom - alpha D glucose

6 C and 6 O atoms - alpha B glucose (OH and H on carbon 1 are flipped)

6 C and 5 O - fructose