Overview of metabolism and revision from basic biochemistry
Learning objectives:
1. Define metabolism, catabolic & anabolic pathways
2. Define the principle characteristics of MP
3. Describe & explain how certain metabolic reaction & thus pathways use ATP to make thermodynamically
unfavourable process favourable
4. Define phosphoryl transfer potential & explain their roles as recurring motif is in metabolism
5. Describe & explain the principle ways that metabolic pathways are regulated.
What need to know for exam?
1. In general: the overall process for each pathway
What it does
What does it make
Where it takes place
When does it happen
2. In detail: the key regulatory steps within
Which steps are crucial
What are they in detail
How are they regulated
LO1. DEFINE METABOLISM, CATABOLIC & ANABOLIC PATHWAYS
Define metabolism?
Metabolism:
- The sum total of the chemical that occur in living organisms, resulting in growth, production of energy,
elimination of waste material
2 general purposes (thus 2 general classification):
1. To capture energy from the environment and convert it to a form suitable for us (cellular work)
2. To transform groups of organic compounds into 1 another, particularly the transformation of small
organic compounds into macromolecules
The 2 aspects of metabolism are interdependent; neither can occur without the other
On one half, cells obtain energy by exergonic breakdown of organic compounds
On the other hand, a major use of stored energy is the synthesis of macromolecules
Laws of thermodynamics:
1st law: law of conservation of energy
- Energy cannot be created nor destroyed, only transferred
nd
2 law:
- Entropy of any isolated system always increases
Energy capture & storage
Cells isolate energy from the environment by 2 major routes:
1. Phototrophs:
- Green plants and algea capture light energy through photosynthesis
2. Chemotrophs:
- Animal cells and most microorganisms obtain energy by breaking down organic compounds that are high
in chemical energy (particularly sugars & lipids) into products with less chemical energy
, From capture & storage to energy use
During these degradations, the energy that is released is captured and stored
- The stored energy can be used at a later time to perform cellular work
The 2nd purpose of metabolism is the conversion of this rather small set of compounds into a larger and more
diversified set of molecules
Thousands of reactions each catalysed by a specific enzyme, split, join together and rearrange the atoms create
almost everything
Metabolism- complex not random & all dependent on another
Not random
- Every reaction is part of a larger scheme, each reaction connected to another through metabolic
pathways
- E.g. conversion of glucose to pyruvic acid
Learning objectives:
1. Define metabolism, catabolic & anabolic pathways
2. Define the principle characteristics of MP
3. Describe & explain how certain metabolic reaction & thus pathways use ATP to make thermodynamically
unfavourable process favourable
4. Define phosphoryl transfer potential & explain their roles as recurring motif is in metabolism
5. Describe & explain the principle ways that metabolic pathways are regulated.
What need to know for exam?
1. In general: the overall process for each pathway
What it does
What does it make
Where it takes place
When does it happen
2. In detail: the key regulatory steps within
Which steps are crucial
What are they in detail
How are they regulated
LO1. DEFINE METABOLISM, CATABOLIC & ANABOLIC PATHWAYS
Define metabolism?
Metabolism:
- The sum total of the chemical that occur in living organisms, resulting in growth, production of energy,
elimination of waste material
2 general purposes (thus 2 general classification):
1. To capture energy from the environment and convert it to a form suitable for us (cellular work)
2. To transform groups of organic compounds into 1 another, particularly the transformation of small
organic compounds into macromolecules
The 2 aspects of metabolism are interdependent; neither can occur without the other
On one half, cells obtain energy by exergonic breakdown of organic compounds
On the other hand, a major use of stored energy is the synthesis of macromolecules
Laws of thermodynamics:
1st law: law of conservation of energy
- Energy cannot be created nor destroyed, only transferred
nd
2 law:
- Entropy of any isolated system always increases
Energy capture & storage
Cells isolate energy from the environment by 2 major routes:
1. Phototrophs:
- Green plants and algea capture light energy through photosynthesis
2. Chemotrophs:
- Animal cells and most microorganisms obtain energy by breaking down organic compounds that are high
in chemical energy (particularly sugars & lipids) into products with less chemical energy
, From capture & storage to energy use
During these degradations, the energy that is released is captured and stored
- The stored energy can be used at a later time to perform cellular work
The 2nd purpose of metabolism is the conversion of this rather small set of compounds into a larger and more
diversified set of molecules
Thousands of reactions each catalysed by a specific enzyme, split, join together and rearrange the atoms create
almost everything
Metabolism- complex not random & all dependent on another
Not random
- Every reaction is part of a larger scheme, each reaction connected to another through metabolic
pathways
- E.g. conversion of glucose to pyruvic acid
