Cellular Respiration

Videos

Cellular Respiration Video Link1.Cellular Respiration – Releasing stored energy by

breaking down glucose

2.Aerobic Cellular Respiration

Cellular Respiration Overview

• Transformation of food into chemical

energy cells can use: ATP

• These reactions proceed the same way in

plants and animals.

• Overall Reaction:

• C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy

Glycolysis

• Occurs in the cytoplasm

• Series of reactions which breaks the 6-carbon

glucose molecule down into two 3-carbon

molecules called pyruvate

• Yields 2 ATP molecules for every one glucose

molecule broken down

• Yields 2 NADH per glucose molecule

Glycolysis

• The next step of cellular respiration depends on

one very important reactant in the equation:

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy

• Depending whether oxygen is present or not is

what decides which type of respiration the

organism will enter into…

Presence of Oxygen

• Aerobic Respiration – oxygen present

• Anaerobic Respiration – no oxygen present

Aerobic Cellular Respiration

• Aerobic - Oxygen present

• 2 sets of reactions occur in the

mitochondria during aerobic respiration

1. The Kreb’s Cycle

2. Electron Transport Chain

The Kreb’s Cycle

• Pyruvic Acid is shuttled into the mitochondrial matrix -

the fluid-like part of the mitochondria and converted

into Acetyl CoA

• Completes the breakdown of glucose

• Takes the Acetyl CoA (3-carbons) and breaks it down

• Hydrogens (H2) are stripped off the Acetyl CoA, two

by two, to extract the electrons for making ATP

• All that is left of the sugar is CO2 - a waste

product - and H2O

• Production of only 2 more ATP but many NADH which

will move on…

Electron Transport Chain

• Occurs in the christae of the mirochondria - the

folded membranes inside the chloroplast.

• Uses the high-energy electrons from the Krebs

Cycle to convert ADP to ATP.

• HOW???

• Electrons from Hydrogen are carried by NADH

and passed down an electron transport chain to

result in the production of ATP

Anaerobic Cellular Respiration

• Anaerobic - Oxygen NOT present

• Also termed fermentation

• Alcohol Fermentation

• Occurs in plants and bacteria

• Alcohol and carbon dioxide is formed.

• 2 ATP is formed

• Lactic Acid Fermentation

• Occurs in animals.

• Lactate is formed.

• 2 ATP is formed.

Energy Tally

• 36 ATP for aerobic vs. 2 ATP for anaerobic

• Glycolysis 2 ATP

• Kreb’s 2 ATP

• Electron Transport 32 ATP

36 ATP

Cellular Respiration

Comparing Photosynthesis & Respiration

Photosynthesis Cellular Respiration

Function Energy Storage Energy Release

Location Chloroplasts Mitochondria

Reactants CO2 and H2O C6H12O6 and O2

Products C6H12O6 and O2 CO2 and H2O

Equation 6CO2 + 6H2O

C6H12O6 + 6O2

C6H12O6 + 6O2

6CO2 + 6H2O