What is cell metabolised defined as?
The highly integrated network of chemical reactions that occur within cells
What does the network of chemical reactions involved in cell metabolism consist of?
A number of distinct chemical pathways (metabolic pathways) which link together
Do the metabolic pathways occur in all cells?
Some do, whilst others are confined to cells with specific functions
What is produced from cell metabolism of nutrients?
- Energy for cell function and synthesis of cell components
- Building block molecules
- Organic precursor molecules
- Biosynthetic reducing power
In what form is energy produced by cell metabolism?
ATP
What are the building block molecules produced by cell metabolism used for?
Synthesis of cell components needed for growth, maintenance, repair and division of the cell
What are the organic precursor molecules produced by cell metabolism used for?
To allow the inter-conversion of building block molecules
Give an example of an organic precursor molecule produced by cell metabolism
Acetyl-CoA
What is the biosynthetic reducing power produced by cell metabolism used in?
The synthesis of cell components
What molecule holds biosynthetic reducing power?
NADPH
What sources provide cells nutrients?
- Diet
- Synthesis in the body tissue
- Release from storage
What can happen to cell nutrients after being metabolised?
- Degradation to release energy
- Synthesis of cell components
- Storage
In what tissues can nutrients be degraded to release energy?
All
In what tissues can nutrients be used to synthesise cell components?
All tissues except RBCs
In what tissues can nutrients be metabolised to storage?
- Liver
- Adipose tissue
- Skeletal muscle
What is catabolism?
The breakdown of larger molecules into smaller ones
What is anabolism?
Where smaller molecules are built up into larger ones
How are catabolism and anabolism involved in cell metabolism?
Cell metabolism consists of pathways in which the overall reaction is catabolism linked to anabolism
Are catabolism pathways oxidative or reductive?
Oxidative
What is meant by catabolic pathways being oxidative?
They release H+ ions (reducing power)
What do catabolic pathways release?
- Large amounts of free energy
- Intermediary metabolites
Are anabolic pathways oxidative or reductive?
Reductive
What is meant by anabolic pathways being reductive?
They use H+ ions
What do anabolic pathways do?
Use the intermediary metabolites and energy (ATP) produced by catabolism to drive the synthesis of important cell components
What happens if energy intake from food is insufficient for cells function?
The body utilises energy stores to keep the supply of energy continuous
What does metabolism couple?
The energy released from exergonic reactions to the energy required by endergonic reactions
What is required in the coupling of exergonic reactions and endergonic reactions in metabolism?
An intermediate process - the ADP/ATP cycle
What is an exergonic reaction?
One that is energy releasing
Is the Gibbs Free Energy positive or negative in exergonic reactions?
Negative
Give three examples of phosphorylated compounds
- Phosphonenolpyruvate
- Creatine phosphate
- ATP
