bioenergetics Flashcards
autotrophs
use light to obtain energy
heterotrophs
obtain energy from eating other organisms
lithotrophs
nitrogen or sulfur fixing bacteria
gibbs free energy
reflects the overall spontinaeity of a reaction / favorability
- thermodynamic and depends on enthalpy and entropy
gibbs free energy eqn
ΔG = ΔH- TΔS
gibbs free energy eqn
ΔG = ΔH- TΔS
-ΔG
spontaneous and exergonic
- perform work on sorroundings
+ΔG
not spontaneous and endergonic
- work is performed on the system by sorroundings
ΔG vs ΔG˚
ΔG˚is standard measure of favorability
ΔG maximum energy under any condition
ΔG˚eqn
ΔG˚= -RT lnKeq
ΔG eqn
ΔG˚+ RTlnQ
coupling exergonic and endergonic reactions
couple favored with unfavored reactions in a cell
is ATP hydrolysis ender or exergonic
highly endergonic and favorable
ΔG˚ or ΔG <0
spontaneous reaction
and Keq>1
main strategies for obtaining cellular energy
- high energy bonds
- Redox reactions
primary example of obtaining energy through high energy bonds
Adenosine triphosphate
the 3 phosphate groups attached by phosphoannhydride bonds can be hydrolyzed to yield adp or amp
product of ATP hydrolysis of a single phosphoannhydride bond
ADP + pi
GTP for energy
contains same phosphoannhydride bonds as ATP and can under go hydrolysis
acetyl coA for energy
high energy thioester
most common mechanism of atp synthesis
ETC via atp synthase and oxidative phosphorylation
standard reduction potential
how much something wants to be reduced
o2 is highest in ETC , complex 1 is least
standard reduction potential of electrochemical cell
E∘cell=E∘cathode−E∘anode
E(reduced) - E (oxidized)
oxidation potential
E.cell = -O. cell
redox reaction for NADH
NAD+ 1H + 2 e- –> NADH
accepts 1 h and 2 e
redox reaction for FADH2
FAD+ + 2H + 2 e- –> FADH2
physiological ph range
7.35 to 7.45
what cells secrete insulin
beta cells of pancreas
what cells secrete glucagon
alpha cells of pancreas
what does insulin do
decrease BGL by increasing glucose uptake
what signals up-regulate insulin release
voltage gated calcium into beta cells, argenine, leucine, ach, cholesytochiline , GLPand GIP
what signals inhibit insulin
epinephrine glucagon
insulin responsive tissue
muscle, adipcoytes
GLUT 4
glucose transporters that come to surface of insulin responsive tissue (adiopse and skeletal muscle)
insulin metabolic effecst
increased glycolyisis, decreased gluconeogenesis, increased glycogenesis, fatty acid synthesis
what gluconeogenic enzyme does insulin inhibit
pyruvate carboxylase
how does insulin affect proteolysis
inhibits
diabetes mellitus
dysregulation of insulin in type 1 –> autoimmune attack on beta cell s
type 2 –> gradual dissensitivity to insulin
treatment for T2 diabetes
diet modifications and hyperglycemic meds
glucagon produced in
alpha cells of pancreas
what does glucagon do
release glucose into blood due to low BGL
what metabolic activities does glucagon promote
gluconeogenesis, glycogenolysis, inhibits glycolysis,
what molecules promote lipolysis
glucagon, cortisol, epinephrine
