Lecture 18: Introduction to Metabolism Flashcards
Metabolism
- an interconnected web of biochemical reactions
Series of reactions are
categorized into different metabolic pathways
Main purpose of metabolism (3)
- Generate energy
- Produce important molecules
- Eliminate toxic chemicals
Anabolism
- building of complex molecules from numerous simple ones with useful energy (ATP)
Catabolism
- the breakdown of complex molecules (fuel) into numerous simple ones
Adenosine Triphosphate
ATP to ADP process
ATP to AMP
How is free energy released?
ATP hydrolysis
ATP is commonly
hydrolyzed to ADP
ATP can be used to drive….
thermodynamically unfavourable reactions
ATP is the key intermediate between….. they can……
- Phosporyl group transfer reactions.
- Can accept/donate phosphoryl groups from/to important metabolites
After stored ATP and creatine phosphate is used up, ATP is….
- regenerated through aerobic and anaerobic metabolism
As muscle ATP decreases….
creatine phosphate acts as a phosphoryl buffer and replenish the ATP supply
Creatine Phosphate
a reserve of high-energy phosphate groups that can be used to rapidly generate ATP (adenosine triphosphate) during intense physical activity.
—– reactions releases energy
oxidation
most energy comes from molecules that are most …
- reduced
Carbons in carbohydrates and fats is….
oxidized to CO2 one carbon at a time, and the energy released is used to regenerate ATP from ADP and Pi
Oxidation:
lose electron (gain C-O bonds)
Reduction
- gain electrons (Lose C-O bonds)
Redox reaction
Transfer of e- between two molecules
To determine if a molecule is oxidized or reduced:
- determine oxidation number
- count bonds to oxygen
Increase in oxidation numbers mean
oxidation
Decrease in oxidation numbers mean
reduction
FInding oxidation via electronegativity:
FInding oxidation via number of oxygen bonds:
Activated carrier (5)
What it is+ ex
Molecule carrying a group that can be readily donated to other molecules. They may carry:
- Phosphoryl groups: ATP
- Electrons for fuel oxidation: Nicotinamide adenine dinucleotide (NADH), flavin adenine dinucleotide (FADH2)
- Electron for biosynthesis: nicotinamide adenine dinucleotide phosphate (NADPH)
- Two-carbon units: acetyl-coenzyme A (acetyl-CoA)
Activated carriers of electron for fuel oxidation: NADH
reactive site + what happens
- NAD+ is not carrying electrons, NADH is carrying electrons
Activated carriers of electron for fuel oxidation: FADH2
reactive site + what happens
Activated Carriers of two-carbon units: Acetyl-CoA
—- is the precursor to many activated carriers
Vitamin B
Activated carriers (ATP, NADH, NADPH, FADH2 and acetyl-CoA) are kinectically stable this means… + stability results in…(2)
- they react very slowly without specific catalyst enzymes, aka they dont react spontaneously.
- This stability results in enzymes controlling the flow of metabolism
Metabolis is —– to maintain —- and to respond to —–
- highly regulated
- homeostatsis
- changing environmental conditions
Regulation of metabolism (3)
The energy status of a cell controls metabolism. What is energy charge?
formula+what high EC mean
- Measure of how much energy is in a cell (cell’s energy status)
