Metabolism Flashcards
What is metabolism?
The process which living systems acquire and use free energy in order to carry out their functions
What does anabolic mean?
The synthesis of biomolecules from simpler components
What does catabolic mean?
The degradation of nutrients to salvage components and gain energy
What are the 2 key principles that govern metabolism?
Common evolutionary origin
Laws of thermodynamics
What is an autotroph?
Autotrophs synthesise all cellular components from simple molecules
What is a photoautotroph?
Photoautotrophs use light to produce carbohydrates which are oxidised giving free energy
What are chemolithotrophs?
Chemolitrophs obtain free energy from inorganic compound oxidation
What is a heterotroph?
A heterotroph oxides carbs, lipids and proteins
What is the main oxidising agent?
O2
How do we obtain vitamins?
Diet
What are the 2 types of pathways ?
Degradative pathways
Biosynthetic pathways
What is a -ve ∆G, +ve ∆G and 0 ∆G ?
-ve ∆G = Favourable
0 ∆G = Equilibrium
+ve ∆G = unfavourable (needs ATP input)
What is ∆G?
Free energy
What do all reactions use to increase speed?
Enzymes
Where can metabolic reactions occur? (8)
Cytosol RER SER Mitchondrion - matrix Nucleus Peroxisome Lysosome Golgi apparatus
What are the 4 types of carb metabolism?
Glycolysis (glucose breakdown)
Gluconeogenesis (Synthesis of glucose)
Glycogen breakdown, glycogen synthesis
Pentose phosphate pathway
What are the 2 types of fat metabolism?
Synthesis of free fatty acids
Mobilization of TAGs and breakdown of FFA
What are the 2 Amino acid metabolism processes?
Removal of amino group to from NH4+
Urea cycle
What is a metabolic role of the liver?
Metabolism of carbs, lipid and A.A
What is a metabolic role of the muscle? (2)
ATP production for muscle contraction
Source of A.A. in short-term starvation
What is a metabolic role of the brain?
Nerve transmission - high ATP requirement
What is a metabolic role of adipose?
Fat synthesis and storage
What drives ATP synthesis?
Proton gradient
Where is the electron transport chain found?
Inner mitochondrial membrane
What are the 2 mobile electron carriers in the ETC?
Coenzyme Q and cytochrome C
What happens at complex 1 of the ETC?
NADH binds and transfers electrons to Q
What happens at complex 2 of the ETC? (2)
Accepts electrons from FADH
Transfers electrons to Q
What is coenzyme Q?
Small lipid compound that transfers electrons
What happens at complex 4 of the ETC? (2)
8 electrons pumped across IMM
Water molecule produced
Why transfer electrons?
Protons pumping across the IMM creates a proton gradient - drives ATP synthesis
What is ATP synthase?
Rotates as protons pass down the channel - conformational change of ADP to ATP
Why does our body not just use glycolysis?
Oxidative phosphorylation is much more efficient
What are 3 inhibitors of the ETC?
Rotenone, Antimycin A, Cyanide azide
