Week 5 - Metabolism Flashcards
What is metabolism
the sum of all chemical reactions involved in maintaining the dynamic state of a cell organism
What is a pathway
A series of biochemical reactions
What is catabolism
The biochemical pathways that are involved in generating energy by breaking down large nutrient molecules into smaller molecules with the concurrent production of E
What are the 3 stages of catabolism
- Hydrolysis of complex molecules to their component building blocks
- Conversion of building blacks to acetyl CoA (or other simple intermediates)
- Oxidation of acetyl CoA; oxidative phosphorylation
What is anabolism
The pathways by which biomolecules are synthesized
What is the equation for metabolism
catabolism + anabolism = metabolism
What are the different locations where metabolic reactions occur
- cell (plasma) membrane
- Cytosol (solution outside of organelles)
- mitochondrion
What energy production occurs in the cell membrane
- hormone recognition (adrenaline)
- nutrient/metabolite transport
What energy production occurs in the cytosol
- glycolysis
- pentose phosphate path
- lipid synthesis
What energy production occurs in the mitochondrion
- fatty acid oxidation
TCA cycle
electron transport - oxid phosphorylation
How is ATP a common currency for the storage and transfer of energy
The hydrolysis of the terminal phosphate of ATP to produce ADP releases energy - as the phosphoanhydride bond is a high energy bond
(Notes: the hydrolysis of a phosphoanhydride bond liberates more energy than hydrolysis of a phosphoester bond)
What is the function of ATP
Phosphorylation of ADP to ATP requires energy
When the high energy bond in ATP is cleaved the energy released is used to drive other reactions that are coupled to it
Hydrolysis of ATP to ADP releases energy
What are the key molecules in metabolism
- NAD+/NADH - Nicotinamide adenine dinucleotide
- NADP+/NADPH - Nicotinamide adenine dinucleotide phosphate
- FAD/FADH2 - Flavin adenine dinucleotide
- CoA/ Acetyl-CoA - coenzyme A
- G-6-P Glucose-6-phosphate
What is NAD+/NADH
Nicotinamide adenine dinucleotide
NAD+ = 2 electron oxidizing agent (this is reduced)
NADH = 2 electron reducing agent (gets oxidized)
Used tocapture energy and give it back in different reactions e.g. glyclosysis, electron transport system, TCA
What is the structure of NAD+
*need to be able to recognize the components of the molecule
What is FAD
Flavin Adenine Dinucleotide
What is NADP+/NADPH
Nicotinamide adenine dinucleotide phosphate (NADP+)
NADP+ = biological oxidsing agent
NADPH = 2 electron reducing agent (very powerful one), and is oxidised to NADP+ and transports a H+
Used in Fatty acid biosynthesis (and pentose phosphate pathway, but not important)
What is Acetyl-CoA
Used in TCA, FA synthesis and cholesterol synthesis
Has a high energy thioester bond
What is the structure of CoA
What is G-6-P
Glucose-6-phosphate
Found in glycolysis step 1
Can also be used in several other pathways:
- pentose phosphate pathway (NADPH synthesis)
- glycogen synthesis
- phosphoketolase pathway (alternative pathway for the formation of energy used by bacteria_
What are the 3 basic stages in catabolism
- Hydrolysis of complex molecules to their component building blocks
- Conversion of building blocks to acetyl CoA (or other simple intermediates)
- Oxidation of acetyl CoA: oxidative phosphorylation to produce ATP and CO2
What are carbohydrates
Simple sugars which are carbon-hydrates
e.g.
Glucose = C6H12O6
Sucrose = C12H22O11
What is the structure of carbohydrates
All D form - using the hydroxyl group (if the OH on the bottom chiral centre points to the right, it is referred to as D-)
What are monosaccharides
A carbohydrate that cannot be hydrolyzed to a simpler carbohydrate
What is the structure of D- Glucose
C6H12O6
Remember: SOS - same side, other side, same side - for the position of the hydroxyl group
Example of pentose sugars C5
- D-Ribose (sugar found in RNA)
- 2-Deoxy-D-ribose (sugar found in DNA)
Example of Hexose sugars C6
- D-glucose (blood sugar)
- D-fructose (found in sweet fruits and honey) - a type of ketohecose sugar (has a ketone functional group)
What is glucose
An aldohexose monosaccharide
Glucose is the immediate fuel source for cellular respiration
What is the structure of glucose in solution
NAD+
Coenzyme A
NADH
Acetyl-CoA
G-6-P
Glucose-6-Phosphate
a-D-Glucopyranose
b-D-Glucopyranose (glucose in solution)
