Lecture 22 - Extracting energy from fuel molecules

Question 1

First law of thermodynamics and how it does it relate to human body

Answer 1

• Energy cannot be created or destroyed
• Only be converted
• The total energy within a system is constant
  meaning that energy from food us covered into forms used for cellular work

Question 2

What is anabolism

Answer 2

Anabolism is the process of building larger molecules, requiring energy ATP

Question 3

What is catabolism

Answer 3

Catabolism is the breakdown of large molecule, releasing energy used to synthesise ATP

Question 4

Why is ATP suited to act as the energy currency in cells

Answer 4

ATP has high-energy phosoagte bonds, is easily hydrolysed to release energy and can be regenerated easily

Question 5

Hydrolysis

Answer 5

• Reaction where a chemical bond is broken using water
• Water molecule is consumed in the separation of a larger molecule into smaller parts

Question 6

Four macronutrients and monomers they are composed of

Answer 6

Carbohydrates - monosaccharides
Protein - amino acid
Lipids - fatty acids
Nucleic acid - nucleotides

Question 7

Digestion involves

Answer 7

1. Hydrolysis of bonds connecting monomer units
2. absorption from GI into body

Question 8

Micronutrients for ATP synthesis

Answer 8

Minerals and vitamins

Question 9

Minerals

Answer 9

Inorganic elements in the diet
Major - greater abundance in the body e.g. Mg as a co factor
Minor - Concentration so low e.g. Fe in harm

Question 10

Vitamins

Answer 10

Organic substances usually essential in diet
Classified as;
Water soluble - not stored, B
Fat soluble - can be stored, D, E, A, K

Question 11

Cofactors and coenzymes

Answer 11

Minerals and vitamins are often cofactors
- small molecules required for the activity of an associated enzyme
Coenzyme;
- type of cofactor
- organic, often from vitamins

Question 12

Three key features of coenzymes in the pathways

Answer 12

• Low concentration in cells
• Acts a carriers
• Have two forms (Oxidised/reduced)

Question 13

Key coenzymes

Answer 13

• NAD
• FAD
• CoA

Question 14

Gibbs free energy

Answer 14

The G of reaction tells us about the energy stored in the chemical bonds of the products and substrates
G<0 - Reaction spontaneous, favourable, energy released
G=0 - reaction at equilibrium
G>0 - reaction not spontaneous, more energy required, unfavourable

Question 15

ATP spontaneity

Answer 15

ATP hydrolysis; energetically favourable
ATP synthesis; Energetically unfavourable

Question 16

Two key reaction types

Answer 16

1. Those involving ADP and ATP
2. Redox reactions ; fuel molecules get oxidised

Question 17

Oxidation reactions

Answer 17

Energy is released for ATP synthesis from fuel molecules by oxidation reactions

Question 18

Reducing equivalents

Answer 18

refers to hydrogen atoms or electrons that are transferred during redox reactions in metabolic pathways