Chpt 26 Metabolism Flashcards
three possible outcomes for digested food molecules absorbed by the
gastrointestinal tract:
supply energy
serve as building blocks stored for future use
metabolism
All chemical reactions occurring in body
Catabolism
break down complex molecules
Exergonic – produce more energy than they consume
example of catabolism
Ex. breaking down food molecules
Anabolism
combine simple molecules into complex ones
Endergonic – consume more energy than they produce
example of anabolism
Creating complex molecules (proteins, glycogen
anabolic reactions transfer energy from
ATP to complex molecules
catabolic reactions transfer energy from
complex molecules to ATP
Adenosine triphosphate (ATP)
ADP + P + energy= ATP
Removal of P from ATP releases energy
Oxidation
removal of electrons
Decrease in potential energy
Dehydrogenation
removal of hydrogens
Liberated hydrogen transferred by
coenzymes
NAD+ (Nicotinamide adenine dinucleotide)
NADH + H+ NAD+ + 2 H+ + 2e-
FAD (Flavin adenine dinucleotide)
FADH2
FAD + 2 H+ + 2e-
Glucose is oxidize
Reduction
addition of electrons
Increase in potential energy
NADH, FADH2
“LEO says GER”
Phosphorlyation
= addition of phosphate groups
Substrate-level phosphorylation
Transferring high-energy phosphate group from
an intermediate directly to ADP
(ie. creatine phosphate)
Oxidative phosphorylation
Remove electrons and pass them through
electron transport chain to oxygen
Photophosphorylation
Only in chlorophyll-containing plant cells
Fate of glucose depends on needs of body
cells
ATP production
synthesis of amino acids, glycogen, or triglycerides
GluT transporters bring
glucose into the cell
via facilitated diffusion
cellular respiration
A) Glycolysis
-Anaerobic respiration – does not require
oxygen
B) Formation of acetyl coenzyme A
C) Krebs cycle reactions
D) Electron transport chain reactions
-Aerobic respiration – requires oxygen
glycolysis
Splits 6-carbon glucose into 2 3-carbon
molecules of pyruvic acid
Consumes 2 ATP but generates 4 ATP
If oxygen is scarce (anaerobic)
reduced to lactic acid
If oxygen is plentiful (aerobic)
converted to acetyl
coenzyme A
cellular respiration begins with
glycolysis
The Krebs cycle (citric acid cycle)
where does the krebs cycle occur
Occurs in matrix of mitochondria
krebs cycle
Series of redox reactions
2 decarboxylation reactions release CO2
Reduced coenzymes (NADH and FADH2) are
the most important outcome
Reduced = gain electrons
One molecule of ATP generated by substrate-
level phosphorylation
electron transport chain
Series of electron carriers in inner mitochondrial
membrane reduced and oxidized (cytochromes)
electron transport chain process
As electrons pass through chain, the H+ gradient
is used to form ATP (ATP synthase)
Need H+ and ADP
Called Chemiosmosis
Final electron acceptor is oxygen to form water
how many ATP in total
32 per glucose molecule
glycogenesis =
glucose storage
glycogenolysis =
glucose release
gluconeogenesis =
formation of glucose from proteins and fats
