Cellular Respiration

1
Cellular Respiration
2
Cellular Respiration

• A catabolic, exergonic, oxygen (O2) requiring
  process that uses energy extracted from
  macromolecules (glucose) to produce energy (ATP)
  and water (H2O).
• C6H12O6 6O2 ? 6CO2 6H2O energy

3
Question

• In what kinds organisms does cellular respiration
  take place?

4
Plants and Animals

• Plants - Autotrophs self-producers.
• Animals - Heterotrophs consumers.

5
Mitochondria

• Organelle where cellular respiration takes place.

6
Redox Reaction

• Transfer of one or more electrons from one
  reactant to another.
• Two types
• 1. Oxidation
• 2. Reduction

7
Oxidation Reaction

• The loss of electrons from a substance.
• Or the gain of oxygen.
• C6H12O6 6O2 ?6CO2 6H2O energy

8
Reduction Reaction

• The gain of electrons to a substance.
• Or the loss of oxygen.

9
Breakdown of Cellular Respiration

• Four main parts (reactions).
• 1. Glycolysis (splitting of sugar)
• a. cytosol, just outside of mitochondria.
• 2. Grooming Phase
• a. migration from cytosol to matrix.

10
Breakdown of Cellular Respiration

• 3. Krebs Cycle (Citric Acid Cycle)
• a. mitochondrial matrix
• 4. Electron Transport Chain (ETC) and
• Oxidative Phosphorylation
• a. Also called Chemiosmosis
• b. inner mitochondrial membrane.

11
1. Glycolysis

• Occurs in the cytosol just outside of
  mitochondria.
• Two phases (10 steps)
• A. Energy investment phase
• a. Preparatory phase (first 5 steps).
• B. Energy yielding phase
• a. Energy payoff phase (second 5 steps).

12
1. Glycolysis

• A. Energy Investment Phase

13
1. Glycolysis

• B. Energy Yielding Phase

14
1. Glycolysis

• Total Net Yield
• 2 - 3C-Pyruvate (PYR)
• 2 - ATP (Substrate-level Phosphorylation)
• 2 - NADH

15
Substrate-Level Phosphorylation

• ATP is formed when an enzyme transfers a
  phosphate group from a substrate to ADP.

Example PEP to PYR
16
Fermentation

• Occurs in cytosol when NO Oxygen is present
  (called anaerobic).
• Remember glycolysis is part of fermentation.
• Two Types
• 1. Alcohol Fermentation
• 2. Lactic Acid Fermentation

17
Alcohol Fermentation

• Plants and Fungi ? beer and wine

18
Alcohol Fermentation

• End Products Alcohol fermentation
• 2 - ATP (substrate-level phosphorylation)
• 2 - CO2
• 2 - Ethanols

19
Lactic Acid Fermentation

• Animals (pain in muscle after a workout).

20
Lactic Acid Fermentation

• End Products Lactic acid fermentation
• 2 - ATP (substrate-level phosphorylation)
• 2 - Lactic Acids

21
2. Grooming Phase

• Occurs when Oxygen is present (aerobic).
• 2 Pyruvate (3C) molecules are transported through
  the mitochondria membrane to the matrix and is
  converted to 2 Acetyl CoA (2C) molecules.

22
2. Grooming Phase

• End Products grooming phase
• 2 - NADH
• 2 - CO2
• 2- Acetyl CoA (2C)

23
3. Krebs Cycle (Citric Acid Cycle)

• Location mitochondrial matrix.
• Acetyl CoA (2C) bonds to Oxalacetic acid (4C -
  OAA) to make Citrate (6C).
• It takes 2 turns of the krebs cycle to oxidize 1
  glucose molecule.

24
3. Krebs Cycle (Citric Acid Cycle)
25
3. Krebs Cycle (Citric Acid Cycle)
26
3. Krebs Cycle (Citric Acid Cycle)

• Total net yield (2 turns of krebs cycle)
• 1. 2 - ATP (substrate-level phosphorylation)
• 2. 6 - NADH
• 3. 2 - FADH2
• 4. 4 - CO2

27
4. Electron Transport Chain (ETC) and Oxidative
Phosphorylation (Chemiosmosis)

• Location inner mitochondrial membrane.
• Uses ETC (cytochrome proteins) and ATP Synthase
  (enzyme) to make ATP.
• ETC pumps H (protons) across innermembrane
  (lowers pH in innermembrane space).

28
4. Electron Transport Chain (ETC) and Oxidative
Phosphorylation (Chemiosmosis)

• The H then move via diffusion (Proton Motive
  Force) through ATP Synthase to make ATP.
• All NADH and FADH2 converted to ATP during this
  stage of cellular respiration.
• Each NADH converts to 3 ATP.
• Each FADH2 converts to 2 ATP (enters the ETC at a
  lower level than NADH).

29
4. Electron Transport Chain (ETC) and Oxidative
Phosphorylation (Chemiosmosis)

30
4. ETC and Oxidative Phosphorylation
(Chemiosmosis for NADH)
31
4. ETC and Oxidative Phosphorylation
(Chemiosmosis for FADH2)
32
TOTAL ATP YIELD

• 1. 04 ATP - substrate-level phosphorylation
• 2. 34 ATP - ETC oxidative phosphorylation
• 38 ATP - TOTAL YIELD

33
Eukaryotes(Have Membranes)

• Total ATP Yield
• 02 ATP - glycolysis (substrate-level
  phosphorylation)
• 04 ATP - converted from 2 NADH - glycolysis
• 06 ATP - converted from 2 NADH - grooming phase
• 02 ATP - Krebs cycle (substrate-level
  phosphorylation)
• 18 ATP - converted from 6 NADH - Krebs cycle
• 04 ATP - converted from 2 FADH2 - Krebs cycle
• 36 ATP - TOTAL

34
Maximum ATP Yield for Cellular Respiration
(Eukaryotes)
36 ATP (maximum per glucose)
35
Prokaryotes(Lack Membranes)

• Total ATP Yield
• 02 ATP - glycolysis (substrate-level
  phosphorylation)
• 06 ATP - converted from 2 NADH - glycolysis
• 06 ATP - converted from 2 NADH - grooming phase
• 02 ATP - Krebs cycle (substrate-level
  phosphorylation)
• 18 ATP - converted from 6 NADH - Krebs cycle
• 04 ATP - converted from 2 FADH2 - Krebs cycle
• 38 ATP - TOTAL

36
Question

• In addition to glucose, what other various food
  molecules are use in Cellular Respiration?

37
Catabolism of VariousFood Molecules

• Other organic molecules used for fuel.
• 1. Carbohydrates polysaccharides
• 2. Fats glycerols and fatty acids
• 3. Proteins amino acids

38
(No Transcript)