Cellular Respiration

Cellular RespirationDo Now (Xtra credit – due in 5 minutes. Complete on a

separate sheet of paper):

30 kJ of energy is released when 1 mol of ATP is broken down into ADP.

1 mol of glucose contains 2870 kJ of chemical energy.

If aerobic respiration produces 36 mol of ATP per mol of glucose, what % of the energy is a cell getting from

the glucose it consumes?

ATP = Energy

• The phosphate-phosphate bond broken when ATP ADP + Pi releases 30 kJ/mol of energy.

Solution

• 36 mol ATP x 30 kJ/mol = 1080 kJ

• 1080 kJ / 2870 kJ = 38%

• In other words, aerobic respiration is about 38% efficient at getting energy from glucose into a useable form.

Responding to Your Concerns

• Some updates to the course policies for the 2nd quarter and remainder of the year.

1. The weight of grade categories will be changed. Labs will be reduced from 25% to 20%, and quizzes will be increased from 15% to 20%

2. More labs (25-50%) will be completed on an individual basis.

Cellular Respiration

• Is a complex biochemical pathway that breaks down organic chemicals in order to make ATP.

There are two main types of respiration

• Aerobic respiration requires oxygen and produces lots of energy

• Anaerobic respiration does not require oxygen, but produces little energy

The products of glycolysis are used in two different ways

Glycolysis: The 1st Step

Glucose is split in half, which releases some energy.

The cell can make 2 ATP molecules from 2 ADP + P using the energy. Pyruvic acid is the end-product.

Energy-carrying molecule NAD+ is also “recharged” with electrons.

Fermentation: Chemical Recycling

Alcoholic Fermentation

Ethanolic Fermentation

Produces Ethanol.

Lactic Acid Fermentation – you do this!

World Changing

• About 2.5 Billion years ago, life on Earth changed forever…

• Paleontologists mark this time as the change from the Archaen Era to the Proterozoic.

• About 90% of the species of organisms alive went extinct in a terrible catastrophe…

• What was it???

Photosynthesis Makes Oxygen!

Aerobic respiration, made possible by photosynthesis, produces almost 2,000% more energy than anaerobic!

That’s a lot of ATP!

Aerobic Respiration is what YOU do.

Aerobic Respiration

• 3 main steps:1. Glycolysis splits

sugar into 2 pyruvate molecules

2. Krebs Cycle “burns” pyruvate to make energy + CO2

3. E- trans. Chain in mitochondria produces MANY MANY ATP

Recap

• Cellular Respiration