Chapter 14 Review Flashcards
Catabolism
- Exergonic Reaction
- Degradation of molecules to produce energy and raw material
- Energy from this goes on to Anabolism
Anabolism
- Endergonic Reaction
- Biosynthesis of molecules from simpler molecules.
- Requires Energy
Catabolism and Anabolism are coupled together to make these “high-energy” compounds:
- ATP
- NADH
Molecules that we may degrade:
- Glucose (sugars, aka carbs or monosaccharides)
- Fats
- Proteins
Organisms can be classified by their __________.
metabolism
Autotrophs
“self-feeders”
Chemolithotrophs
Receive energy from the oxidation of inorganic molecules NH3, H2S, Fe2+
Photoautotrophs
Obtain energy through photosynthesis
Obligate aerobes
Need O2 to survive; Us
Facultative anaerobes
Can live with or without O2. Ex: E. coli
Obligate anaerobes
O2 poisons them.
Metabolism of O2 leads to
O2- (superoxide)
_______ we need to consume because we can’t synthesize them ourselves.
Vitamins, minerals and trace elements
What is the most important mineral (especially in regards to ATP)?
Magnesium
All metabolic pathways are connected by _______________.
Enzymatic reactions
Catabolism
- Exergonic process
- Break down
- Produces energy that is then used to make high energy intermediates
Anabolism
- Endergonic
- Biosynthesis
- Requires energy
Glycolysis and the Citric Acid Cycle occur in the _______.
Cytoplasm
With glycolysis, glucose becomes _________, which is then used in the __________.
pyruvate ; mitochondria
What is bioenergetics?
The study of energy transductions
Bioenergetics have to ______________.
OBEY the laws of thermodynamics.
(delta) G
Free energy change of a reaction.
+ (delta) G
The system gains free energy (endergonic)
-Reaction is unfavorable. (nonspontaneous)
- (delta) G
The system loses free energy (exergonic)
-Reaction is favorable. (spontaneous)
(delta) H
change in enthalpy (heat) from the conversion of reactants to products.
+ (delta) H
the system takes in heat (endothermic)
- (delta) H
the system loses heat (exothermic)
(delta) S
change in entropy (disorder) that results from a reaction
+ (delta) S
the products of a reactions are more disordered than the reactants. (entropy increases)
- (delta) S
the products of a reaction are less disordered than the reactants. (entropy decreases)
(delta) G =
(delta) H - T (delta)S
(delta) G* =
-RT ln(Keq)
At equilibrium (or near equilibrium), reactions ______________________.
are easily reversed
Reactions far from equilibrium are ____________.
irreversible
Metabolic pathways are _________.
Irreversible; confers directionality
Every metabolic pathway has ____________.
A committed step (usually an irreversible exergonic step that occurs early on)
Catabolic and Anabolic pathways ________.
differ
The body is at a constant metabolic _______.
Flux
What controls flux?
Rate-determining steps
Flux
The rate of flow of metabolites through a metabolic pathway. Steady state
4 ways to control Flux
1) Allosteric Control (Negative Feedback Regulation)
2) Covalent Modifications (just phosphorylation; ex: hormone signaling)
3) Substrate cycles
4) Genetic Control (make more enzymes = faster reaction)
Metabolism of Glucose
C6H12O6 –> 6CO2 + 6 H2O
-2850 kJ/mol
exergonic reaction
Metabolism of Fatty Acids
C16H32O2 + 23O2 –> 16 CO2 + 16 H2O
-9781 kJ/mol
exergonic reaction
Oxidation of Glucose is used to make ________.
ATP
There is ___________ between the (gamma and beta) phosphate and the (alpha and beta) phosphate of ATP. Thus, when breaking either of these bonds through ________, it ________ (delta) G.
electrostatic ; hydrolyzation ; lowers
There is a large negative free energy change associated with ATP hydrolysis. This comes from these 3 things:
1) Electrostatic Respulsion
2) Resonance stabilization (the free phosphate shares e- better)
3) Solvation energy (energy associated with relieving stress to make it more soluable
High-energy phosphates include
1) Acetyl phosphate
2) 1,3- Bisphosphoglycerate
Low-energy phosphates include
1) alpha-D-Glucose-6-phosphate
2) L-Glycerol-3-phosphate
The four ways for an electron to transfer from a donor to an acceptor
1) Directly as electrons (Redox Rxns).
2) Hydrogen atoms
3) Hydride Ions
4) Through direct combination with oxygen
The two most important electron transfer mechanisms for biological systems:
1) Directly as e-
2) Hydride Ions
