Download Cellular Respiration

Metabolic Processes
• Catabolic Processes (pathways) – capture energy in a form cells can use
by breaking down complex molecules into simpler ones
 Cellular Respiration
• Glycolysis
• Fermentation
• Aerobic respiration
 Fat metabolism
 Protein metabolism
 Light-dependent reactions of photosynthesis
pl. Grana
• Anabolic Processes (pathways) – use energy for:
Chloroplast
 Chemical work (energy for enzymes)
 Biosynthesis of molecules and macromolecules
• Synthesis of amino acids, proteins, polysaccharides, lipids, etc
• Light-independent (dark) reactions of photosynthesis
 Mechanical work (motor proteins – e.g. flagella)
 Transport work (e.g. carrier proteins)
Metabolic Processes
• Catabolic Processes (pathways) – capture energy in a form cells can use
by breaking down complex molecules into simpler ones via oxidation
 Cellular Respiration
• Glycolysis
• Fermentation
• Aerobic respiration
 Fat metabolism
 Protein metabolism
 Light-dependent reactions
of photosynthesis
Cellular Respiration is the transfer of energy stored in the chemical bonds of glucose
molecules to energy carrier molecules (ATP) that take the energy to all parts of the
cell to do work. This occurs via a series of chemical reactions to capture as much
chemical energy as possible (by releasing it in small increments) thereby minimizing
energy lost as heat and other forms.
Metabolic Processes
• Catabolic Processes (pathways) – capture energy in a form cells can use
by breaking down complex molecules into simpler ones via oxidation
 Cellular Respiration
• Glycolysis
• Fermentation
• Aerobic respiration
 Fat metabolism
 Protein metabolism
 Light-dependent reactions
of photosynthesis
One molecule of glucose (6-carbon sugar) is
converted into two molecules of pyruvate (3
carbon sugar) via a series of chemical reactions
that release the energy stored in the chemical
bonds little by little resulting in the production
of 2 ATP and 2 NADH molecules per glucose.
Cellular Respiration
• Glycolysis
 Metabolic pathway used by most prokaryotic and eukaryotic
organisms to break down glucose and capture its energy
 Glucose (6-carbon molecule)  2 pyruvates (3-carbon molecules)
+ 2 NAD+ + 2 ADP
+ 2 NADH + 2 ATP
 10 steps, each involves one or more enzymes
 The enzymes involved in this pathway are highly conserved (found
in all cells – prokaryotes and eukaryotes)
 Not very efficient – a lot of energy still remains tied up in the
pyruvates, which can be further metabolized by organisms capable
of aerobic respiration
Metabolic Processes
• Catabolic Processes (pathways) – capture energy in a form cells can use
by breaking down complex molecules into simpler ones via oxidation
 Cellular Respiration
• Glycolysis
• Fermentation
• Aerobic respiration
 Fat metabolism
 Protein metabolism
 Light-dependent reactions
of photosynthesis
Organisms use energy from
NADH produced from
glycolysis – results in
various “waste products”
depending on the organism
Metabolic Processes
• Catabolic Processes (pathways) – capture energy in a form cells can use
by breaking down complex molecules into simpler ones via oxidation
 Cellular Respiration
Homolactic Acid Fermentation
• Glycolysis
• Fermentation
 NADH is used to convert pyruvate
• Aerobic respiration
(pyruvic acid) to lactic acid
 Fat metabolism
 Occurs in:
 Protein metabolism
• Lactobacilli
(utilized in cheese production)
 Light-dependent reactions
of photosynthesis
• Mammalian muscle cells
(responsible for soar muscles)
Metabolic Processes
• Catabolic Processes (pathways) – capture energy in a form cells can use
by breaking down complex molecules into simpler ones via oxidation
 Cellular Respiration
• Glycolysis
Anaerobic Respiration
• Fermentation
• Aerobic respiration
- Occur without O2
 Fat metabolism
C6H12O6  pyruvate + energy  products of
 Protein metabolism
fermentation
 Light-dependent reactions
(e.g. lactic acid
of photosynthesis
or ethyl alcohol)
Metabolic Processes
• Catabolic Processes (pathways) – capture energy in a form cells can use
by breaking down complex molecules into simpler ones via oxidation
carbon
 Cellular Respiration
glucose oxygen dioxide water
• Glycolysis
C6H12O6 + 6O2  6CO2 + 6H2O + energy!
• Fermentation
• Aerobic respiration
Know this formula for
Requires O2! Aerobic Cellular Respiration!
 Fat metabolism
 Protein metabolism
 Light-dependent reactions
of photosynthesis
Aerobic Respiration
KNOW THIS SLIDE!
 Aerobic respiration starts in the cytoplasm with glycolysis and
concludes in the mitochondria where oxygen is used to help
break down pyruvate to produce ATP.
Aerobic Cellular Respiration
carbon
glucose
oxygen water dioxide
( C6H12O6  pyruvate ) + 6O2  6H20 + 6CO2 + energy
ADP + P  ATP
1
Oxidation
of
Pyruvate
2
3
4
2
2
34
A total of 38
ATP are
produced per
glucose
Aerobic Respiration
1. Oxidation of Pyruvate:
• Pyruvates (from glycolysis) enter matrix of mitochondria in eukaryotes
(whole process takes place at plasma membrane in prokaryotes)
• Pyruvate (3-carbon compound) is converted into a 2-carbon compound
 Energy is released and transferred to NAD and H+ to form NADH (energy
carrier molecule)
 The carbon that was removed pairs with O2 to form CO2 (which exists the cell
as a waste product)
Glycolysis  this step  Kreb’s cycle  electron transport & chemiosmosis
Aerobic Respiration
2. Kreb’s Cycle (Citric Acid Cycle): each 2 carbon compound (acetyl CoA) is processed
through a series of reactions to produce: 3 NADH, 1 FADH2, 1 GTP, and 2 CO2 per
pyruvate (double this to calculate how many per glucose)
- recall that one CO2 was released from the last step so that is a total of 3 CO2 per
pyruvate (6 CO2 per glucose)
Aerobic Respiration
3. Electron Transport Chain (ETC): Electrons are taken from the NADH molecules
and passed down a series of proteins (electron transport chain) that use energy from the
FADH2 molecules to pump H+ into the intermembrane space of the mitochondria
causing positively charged ions to build up inside (like what happens at the ETC in the
thylakoids during the light dependent reactions of photosynthesis)
4. Chemiosmosis: ATP synthase uses energy from the movement of H+ ions flowing out
of the intermembrane space to power the phosphorylation of ADP to ATP (results in 3
ATP per NADH and 2 ATP per FADH2)
Metabolic Processes
• Catabolic Processes (pathways) – capture energy in a form cells can use
by breaking down complex molecules into simpler ones via oxidation
 Cellular Respiration
• Glycolysis
• Fermentation
• Aerobic respiration
Oxidation of
Pyruvate
 Fat metabolism
 Protein metabolism
 Light-dependent reactions
of photosynthesis
Aerobic Respiration
2*
2
34
Conversion of pyruvates (pyruvic acid) into CO2 resulting in production of
18 ATP per pyruvate (that’s 36 ATP per glucose molecule)
• 1 ATP is produced per pyruvate in the Kreb’s Cycle (that’s 2 ATP per glucose)
• 17 ATP are produced per pyruvate during chemiosmosis (that’s 34 ATP per glucose)
• 2 ATP* were produced during glycolysis bringing the total to 38ATP
Metabolic Processes
• Catabolic Processes (pathways) – capture energy in a form cells can use
by breaking down complex molecules into simpler ones via oxidation
 Cellular Respiration
• Glycolysis
• Fermentation
• Aerobic respiration
 Fat metabolism
 Protein metabolism
 Light-dependent reactions of photosynthesis
Metabolic Processes
• Catabolic Processes (pathways) – capture energy in a form cells can use
by breaking down complex molecules into simpler ones via oxidation
 Cellular Respiration
• Glycolysis
• Fermentation
• Aerobic respiration
 Fat metabolism
 Protein metabolism
 Light-dependent reactions of photosynthesis