Intro to respiration Flashcards
What are the 2 types of metabolic pathways?
Anabolic and Catabolic
Define anabolic
pathways requires energy and involved in biosynthesis of complex molecules from simple molecules
Define catabolic
pathway releases energy and involves the breakdown of molecules
What are the 2 functions of oxidative catabolism of glucose?
1- production of free energy in the ATP form
2- Production of intermediates from glycolysis and the TCA cycle to provide materials for other metabolic pathways
Define oxidative metabolism
A chemical process in which oxygen is used to make energy from carbohydrates, also called aerobic metabolism /aerobic respiration/ and cell respiration.
Name the respiration equation.
What is the standard free energy change?
C6H12O6 + 6O2 → 6CO2 + 6H2O
The standard free energy change (G°´) for this reaction is -2834 kJmol-1
Energy that is not used for work is released as what?
Heat
Define Delta G°
Change in Gibbs free energy at pH 0 (1M [H+]) under standard conditions
Define Delta G°´
Change in Gibbs free energy at pH 7 under standard conditions
What does Delta G prime show us about the reaction?
Provides info on what happens to free energy. This amount is related to difference in energy level between products and reactants
If Delta G prime is negative…..
free energy is released hence it is exergonic
If Delta G prime is positive…..
free energy is absorbed hence it is endergonic
Exergonic and Endergonic differ from endo and exothermic reactions- how?
Entropy not included in exo and endo
What are the 4 biological uses of the release of energies?
Mechanical work- eg muscle contraction
Transport work -eg establish ion gradients
Heat Generation
Biochemical Work- eg energy requiring chemical reactions
Define Kc
Define Q
what is their relationship
Kc= Equilibrium constant
Q= reactant quotient
Kc=Q and equilibrium
At equilibrium
State ΔG°
Change in ΔG°
Change in [reactant] and [product]
Delta G=0
No change in free energy
concentrations are constant
State the equation for ΔG°
What does this allow us to do?
ΔG°= -RTlnK
Predict spontaneity if K is known
To estimate if reaction lies to the left or the right if ΔG° is known
Which equation links ΔG and ΔG prime?
ΔG = ΔG°´ + RT lnQ
where Q =[Products]/[Reactants]
Endergonic or Exergonic?
Large Kc
negative ΔG prime
Exergonic
Endergonic or Exergonic?
Small Kc
Positive ΔG prime
Endergonic
Delta G is dependent on two parts
What are they?
A constant term whose value depends only on the reaction taking place
A variable term that depends on the concentration of the reactants and products
If Delta G is negative equilibrium lies in favour of the ….?
Lies in favour of the products
If Delta G is positive, equilibrium lies in favour of the……?
Lies in favour of the reactants
If the Delta G is large and negative what does this mean for the reaction?
The reaction is irreversible
If delta G is large and positive what does this mean for the reaction?
Reaction will not proceed
In reactions with multiple steps what is the relationship between the delta Gs
Delta G are additive
What are the two forms of the enzyme for glucose?
Glucokinase and hexokinase
Are metabolic pathways reversible?
No its irreversible
Describe feedback inhibition
The product of a late or last step frequently acts as an inhibitor of the first committed step. Hence, end product controls its own synthesis. All metabolic pathways are regulated.
Each metabolic pathways have a first committed step
xx
There are 2 forms of glucose- what are they?
D-glucose can be alpha or beta
It can also be cyclic or branched.
The branched version is CHO-ChOH-COHH-CHOH-CH2OH
The 2nd OH is on the left the rest are on the right
