Download ppt - 4.4 Overview of Cellular Respiration KEY CONCEPT Respiration is the metabolic process which uses energy stored in food to make ATP molecules which provide

4.4 Overview of Cellular Respiration

KEY CONCEPT Respiration is the metabolic process which uses energy stored in food to make ATP molecules which provide usable energy to the cells


Two forms of Respiration

1. Aerobic Respiration-Requires Oxygen gas

2. Anaerobic Respiration– No Oxygen gas


Two Forms of Respiration

Anaerobic• Do Not Require Oxygen

• Begins with Glycolysis

• Consists of Reactions: - Glycolysis

- Fermentation

• Produces 2 ATP

• Rxns occur in Cytoplasm

Aerobic• Require Oxygen

• Begins with Glycolysis

• Consists of Reactions:

- Glycolysis

- Kreb’s Cycle

- Electron Transport Chain• Produces 38 ATP• Rxns occur in Cytoplasm and

Mitochondria


Glycolysis is the first step in both types of respiration

• Does Not Require Oxygen• Occurs in cytoplasm• Means “sugar splitting”• Glucose is “split” into two pyruvic acid molecules (Hi E)• Requires the energy from 2 ATP molecules• Net product 2 ATP molecules (makes 4 but requires 2)



Aerobic Respiration (a.k.a. Cellular Respiration)

Chemical Equation of Aerobic Respiration

C6H12O6 + 6O2 6CO2 + 6H2O + Energy • Reactants Products• ___________________ _____________• ___________________ _____________ •


Cellular respiration occurs in the _Mitochondria .


Kreb’s Cycle

• Pyruvic acids molecules made in glycolysis move into the

Mitochondrial matrix and become reactants in the Kreb’s Cycle

• E stored in pyruvic acid is released to form

2 High Energy molecules: ATP and NADH

•Carbon atoms from the breakdown of pyruvic acid form CO2 - a waste product 6H O2

6CO 2

6O 2

mitochondrionmitochondrion

matrix (area enclosedby inner membrane)

inner membrane

ATP

ATP

energy

energy from glycolysis

1

2

4

3

and

and

and


6H O2

6CO 2

6O 2

mitochondrionmitochondrion

matrix (area enclosedby inner membrane)

inner membrane

ATP

ATP

energy

energy from glycolysis

1

2

4

3

and

and

and

Electron Transport Chain

1.) A series of protein molecules embedded in the mitochondrial inner membrane along which “excited” electrons released in glycolysis and Krebs Cycle move along releasing energy used make a large number of ATP molecules

Oxygen which is highly electronegative and attracts the electrons serves as the “final electron acceptor”

•H2O released as byproduct•36 more ATP made

Electron Transport


Anaerobic Respiration

• Occurs in the cytoplasm

• Breakdown of food molecules without oxygen

• Begins with glycolysis (just like in aerobic respiration)

• Glycolysis makes 2 ATP

• The only way glycolysis can keep working is to replace the molecule NAD+ that is the electron acceptor/transporter


Fermentation

• Occurs when Oxygen is not available – anaerobic process

• Occurs in mitochondria

• Resupplies the NAD+ so glycolysis can keep happening and ATP can be made

• NO ATP Made


Two Types of Fermentation

• There are two chemical pathways of fermentation

• They are named for the final product made

• Alcoholic fermentation Lactic Acid fermentation

Yeast – Bread, Wine Muscles - “The Burn”

Bacteria - Yogurt


• Fermentation is used in food production.

– Yogurt

– Cheese

– Bread– Wine


Different organisms produce different fermentation products


• The equation for the overall process is:

C6H12O6 + 6O2 6CO2 + 6H2O

• The reactants in photosynthesis are the same as the products of cellular respiration.


Compare and Contrast the 2 Energy Transformation Processes

• Photosynthesis

6CO2 + 6H2O--------->C6H12O6 + 6O2

• Cellular Respiration

C6H12O6 + 6O2 ---------> 6CO2 + 6H2O