L12: Intro to metabolism Flashcards
Define metabolism
“Totality of chemical reactions & physical changes that occur in living organisms, consisting of anabolism & catabolism”
Define catabolism
Metabolic breakdown of complex substances into smaller products , with the release of energy
Define anabolism
Energy requiring part of metabolism where simpler substances are transformed into more complex ones, with storage of energy
Catabolism
- Name ends in…
- Generates…
- Located in …
- Lysis
- ATP & NADH
- Mitochondria
Anabolism
- Name ends in…
- Uses…
- Located in …
- Genesis
- Uses ATP, GTP & UTP
- In cytosol
Function of stepwise breakdown in metabolism
Releases energy in useable small ‘packages’
What does different ‘forward’ & ‘reverse’ pathways allow?
Separate regulation
W
Where is energy stored in each step of metabolism?
Activated carrier molecules
What is the result of catabolic pathways?
ATP synthesis
Why is hydrolysis of ATP energetically so favourable?
- Relives electrostatic repulsion between phosphate groups
- Release phosphate ion is stabilised; increase entropy
- ‘High energy bond’ is useful
Why is hydrolysis of ATP to AMP + PPi much better than ATP to ADP?
Releases almost twice as much free energy
Functions of ATP
- Used directly in cell motility & muscle contration (motor proteins)
- Used in active transport systems
- Used in metabolic control; regulates enzyme activity
- Used in metabolism to add Pi to metabolic intermediates
Role of UTP
Drives synthesis of complex sugar
Role of GTP
Synthesis of proteins
Name 2 ‘high energy’ nucleotide carriers used to drive specific biosynthetic reactions
- UTP
- GTP
Name group carried in high-energy linkage for these activated carriers:
1. ATP
2. NADH, NAPH,FADH2
3. Acetyl CoA
4. Uridine diphosphate glucose
- Phosphate
- Electrons & hydrogens
- Acetyl group
- Glucose
Role of NAD+
Accepting H atom & carrying them to ETC to synthesis ATP
What is transferred when H atom is transferred?
H+ & e-
What happens to proton when 2 H atoms are transferred to NAD+ from a donor?
One proton (H+) is released to solution
Define reduction & oxidation
Oxidation: loss electrons, gain O2, loss H+
Reduction: gain electrons, lose O2, gain H+
What replaces NADP in anabolic reactions?
NAD
What is acetyl-CoA a carrier of?
An acyl group (2C)
NOT ELECTRONS OR HYDROGENS
What bond links acetyl group to CoA?
‘High energy’ thioester bond
How many stages does catabolism of sugars, fats & amino acids occur in?
3 stages
Name 3 stages of catabolism of sugars, fats & amino acids
- Glycolysis
- Beta-oxidation
- Transamination
