Unit 2 - Metabolic Processes Flashcards
metabolism
catabolic and anabolic processes in a cell or organism
- catabolism: breakdown of molecules (e.g. starch→glucose→CO2 + H2O
- anabolism: building up of molecules (e.g. amino acids→proteins)
1st Law of Thermodynamics
Energy cannot be created or destroyed, but can only be converted from one form to another.
bond energy
the minimum amount of energy require to break one mole of bonds
exothermic reactions
- energy is released
- ΔH = negative
- increase in temperature of the solution
endothermic reactions
- energy is absorbed
- ΔH = positive
- decrease in temperature of the solution
enthalpy
measurement of heat (ΔH)
entropy
- measurement of randomness in energy (ΔS)
- as entropy increases, chaos increases
2nd Law of Thermodynamics
Over time, entropy increases (ΔSuniverse > 0).
free energy
- a.k.a. Gibbs Free Energy
- measurement of energy that can do useful work (ΔG)
- if ΔG = 0, the reaction is in equilibrium
exergonic reactions
- spontaneous (ΔG = negative)
- tend to be exothermic
- e.g. explosions
endergonic reactions
- non-spontaneous (ΔG = positive)
- tend to be endothermic
- e.g. photosynthesis
REDOX agents
molecules that facilitate energy transfer
endosymbiotic theory
- mitochondria evolved from prokaryotes
- proof of this is in its double membrane and its own DNA/RNA (i.e. mitochondrial RNA (mtRNA))
cellular respiration
C6H12O6 + 6O2→ CO2 + H2O
- can be anaerobic (no O2 required) or aerobic (O2 required)
- exergonic
- exothermic
- energy is released or stored as ATP
- made up of four stages:
- glycolysis
- pyruvate oxidation
- Krebs cycle
- electron transfer and chemiosmosis
- prokaryotes only undergo glycolysis
- eukaryotes undergo all four stages
POOPY I POOPY DING-DONG PROPER POOPY I CAN’T POOPY
glycolysis
- anaerobic
- occurs in cytosol
- biochemical pathway made up of 10 reactions:
1. phosphorylation
2. isomerization
3. phosphorylation
4. decomposition
5. decomposition
6. phosphorylation + REDOX
7. phosphorylation
8. isomerization
9. condensation
10. phosphorylation
major products/glucose:
- 2 net ATP
- 2 pyruvate
- 2 NADH
pyruvate oxidation
- occurs in intermembrane space
- reaction is doubled (2 pyruvate/glucose)
- biochemical pathway made up of 3 reactions:
1. decarboxylation
2. REDOX
3. synthesis
major products/glucose:
- 2 CO2
- 2 NADH
- 2 acetyl-CoA
Krebs cycle
- occurs in matrix
- reaction is doubled (2 acetyl-CoA/glucose)
- cyclical biochemical pathway made up of 8 reactions:
1. synthesis
2. isomerization
3. decarboxylation + REDOX
4. decarboxylation + REDOX + synthesis
5. decomposition + indirect phosphorylation
6. REDOX
7. hydration
8. REDOX
major products/glucose:
- 6 NADH
- 4 CO2
- 2 ATP
- 2 FADH2
DIG UNDER BIG COWS ONCE CONNOR, OK?
electron transport chain
(ETC)
- occurs in intermembrane space
- electron transfer and pumping of H+ from matrix into intermembrane space via cytochromes, and then through ATPase complexes to innermembrane space
- biochemical pathway made up of 5 cytochromes:
1. NADH dehydrogenase
2. ubiquinone (Q)
3. cytochrome b-c1 complex
4. cytochrome C (C)
5. cytochrome oxidase complex - final product is sweat (H+ + e- = H2O)
NADH → 3 H+
FADH2 (and NADH from glycolysis) → 2 H+
chemiosmosis
- establishment of chemiosmotic gradient; electrochemical potential
- H+ synthesizes the phosphorylation of ADP to ATP (1 H+ = 1 ATP)
factors that affect ATP synthesis
1. O2 availability
- O2 depletion
- e.g. coronary heart disorder, ischemia
2. glucose availability
- source of NADH and electrons
3. metabolic genetic disorders
- e.g. non-functional cytochromes
4. exposure to toxins, poisons, etc.
- e.g. cyanide binds with cytochromes
5. membreane permeability to NADH/FADH2, or H+
total theoretical yield of ATP
2 net ATP (glycolysis) + 2 ATP (Krebs cycle) + 32 ATP (ETC and chemiosmosis) = 36 ATP
total experimental yield of ATP
34 ATP
regulation of cellular respiration
- more ATP inhibits phosphofructokinase
- more ADP activates phosphofructokinase
- less citrate activates phosphofructokinase
- more NADH inhibits pyruvate decarboxylase
alcohol fermentation
- found in bread-making (yeast) and wine-making
1. glycolysis
2. 2 pyruvate → CO2 + 2 acetaldehyde
3. 2 acetaldehyde → 2 ethanol
major products/glucose
- 2 ATP
- 2 CO2
- 2 ethanol (EtOH)
lactic acid fermentation
- found in muscle cells
1. glycolysis
2. 2 pyruvate → 2 lactate
major products/glucose:
- 2 lactate
- 2 ATP
strenuous activty can cause a lactate buildup
deanimation
removal of an amino group from a molecule
β-oxidation
process by which fatty acids are broken down two carbons at a time into acetyl-CoA molecules, and vice versa
gluconeogenesis
process by which glucose molecules are formed from 2 glycerol, and vice versa
α-ketoglutarate
- inversely proportional with proteins (more α-ketoglutarate = less protein, and vice versa)
- marker for diagnosing neurological conditions in newborns
photosynthesis
CO2 + H2O→ C6H12O6 + 6O2
- synthesis of glucose using light, H2O from the soil, and CO2 from the atomsphere
- endergonic
- endothermic
chlorophyll
a pigment made up of a porphyrin ring and phytol chain
poryphrin ring
- has a metal cation in the middle, and an R-group (CH3 group means chlorophyll a; COH group means chlorophyll b)
- like the heme group in hemoglobin (which contains Fe instead)
phytol chain
- hydrophobic
- helps anchor chlorophyll molecule
molecular control of stomatal opening
usually during the daytime
- Photons activate H+ receptors found in the guard cell membrane; subsequent H+ efflux.
- K+ influx to compensate for ionic differences.
- H2 enters guard cells, via osmosis.
- Guard cells become turgid; stoma opens.
molecular control of stomatal closing
usually during the nightime
- H+ receptors found in the guard cell membrane deactivate; subsequent H+ influx.
- K+ efflux to compensate for ionic differences.
- H2O exits guard cells, via osmosis.
- Guard cells become flaccid; stoma closes.
PETER PIPER BUNDLED 6 PICKLES PEPPERS FOR RICK
light-dependent reactions
- electron transfer and pumping of H+ from stroma into thylakoid lumen via cytochromes, and then through ATPase complexes to thylakoid membrane
- either non-cyclic (photosystem I and II), or cyclic (photosystem l; more ATP used)
- biochemical pathway made up of 7 cytochromes:
water splitting enzyme performs photolysis (H2O → 2H+ + 1/2O2 + 2e+, and then…
1. photosystem II (P680)
2. plastoquinone (PQ)
3. cytochrome b6-f complex
4. plastocyanin (Pc)
5. photosystem I (P700)
6. ferredoxin (Fd)
7. NADP reductase
major reactants:
- H2O
- NADP+
- ADP
major products:
- O2
- ATP
- NADPH
light-independent reactions
- biochemical pathway made up of 3 phases:
1. carbon fixation (synthesis)
2. reduction reactions (phosphorylation, REDOX, dephosphorylation)
3. regeneration of RuBP (regeneration)
major reactants:
- CO2
- ATP
- NADPH
major products:
- G3P (either glucose used for cell walls or cellular respiration, starch stored in amyloplasts, or sucrose used for cellular respiration or transported to other parts of the plant via translocation)
- NADP+
- ADP
chromatography
technique used to separate molecules (e.g. pigments)
Rf equation
Rf = distance travelled by pigment/distance travelled by solvent
chromatographic polarities
if the solvent is polar, the further the pigment travels, the more polar, and vice versa (like dissolves like)
factors affecting successful chromatographic separation
- sufficient sample concentration
- different polarities of sample fragments
- sufficient sample amount
types of photosynthesis
C3 (found in temperate climates)
C4 (found in hot, dry climates)
- additional ATP needed
C.A.M. (found in arid, desert-like biomes)
- additional ATP needed
photorespiration
- the process in which O2 is binded to RuBP via rubisco instead of CO2; causing only one PGA to form
- reduces efficiency, and promotes water loss
C4 photosynthesis
- CO2 is fixed by synthesis with PEP, via PEP carboxylase, to form oxaloacetate (OAA) in the mesophyll cells.
- OAA becomes malate, and is transported into the bundle-sheath cells.
- Malate is decarboxylated and becomes pyruvate; carbon dioxide enters Calvin cycle.
- Pyruvate is transported back into the mesophyll cells, is phosphorated, and becomes PEP.
