Session 5 ILOs - BMI, obesity, malnutrition and undernutrition

Question 1

Define cell metabolism and explain its functions

Answer 1

Cell metabolism is a set of processes which derive energy and raw materials from food stuffs
Functions: support repair, growth, activity of the tissues to sustain life

Question 2

Describe the relationship between catabolism and anabolism

Answer 2

Catabolism is breaking bonds and anabolism is the process of making bonds, catabolism can be used in anabolism to make/create substances (can use intermediary metabolites from catabolism)

Question 3

Explain why cells need a continuous supply of energy

Answer 3

Cells need energy continuously to be able to do various types of work:

1. Biosynthetic work
2. Transport work - maintain ion gradients & nutrient uptake
3. Specialised functions i.e. mechanical work in muscle contraction etc.

Question 4

Explain the roles of redox reactions and H-carrier molecules in metabolism

Answer 4

Redox reactions are a way or harnessing the reducing power, to then power other reactions and it uses H-carrier molecules to do this

1. Directly e.g. use of NADPH in biosynthesis
2. Indirectly e.g. mitochondrial system to couple NADH to the produce ATP = key!

Question 5

Explain the biological role of ATP

Answer 5

ATP is an energy currency molecule, with the energy being stored in the phosphate bond and can be used to drive reactions
ATP/AMP can be used to activate pathways, e.g. if ATP is high then anabolic pathways are activated

Question 6

Explain the biological role of creatine phosphate & other molecules containing high energy of hydrolysis phosphate groups

Answer 6

Creatine phosphate acts as a very quick release, high energy store. When energy levels are high, phosphate bond energy may be stored in phosphocreatine (creatine with an extra phosphate group). Phosphocreatine + ADP can be converted to creatine + ATP by creatine kinase
Phosphoenolpyruvate (PEP) is the same thing but gets converted to pyruvate + Pi which can help to form ATP