Name: ____________________________________ Date: _______________________ !

1

Chapter 9 Notes – Cellular Respiration Section 9-1 Chemical Pathways (p. 221-225)

Why Do We Need Food?

• Food provides cells with the _____________________ building blocks they need to _______________ and __________________________.

o __________________ (carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur)

• Food serves as a source of raw ______________________ from which cells can synthesize new ___________________________.

o __________________________ carbohydrates, lipids, proteins, nucleic acids

• Food serves as a source of _____________________. Chemical Energy and Food How much energy is actually present in food? Quite a lot!

• One gram of the sugar _____________________ (C6H12O6), when burned in the presence of ___________________, releases _______________ calories of heat energy.

o A calorie is the amount of energy needed to raise the temperature of __________________ of water _______________________ Celsius.

o The _____________________ (capital “C”) that is used on food labels is a kilocalorie, or _________________ calories.

E.g., a candy cane has ___________ calories (14 g carbohydrates; 11 g of sugar)

• One candy cane, if burned in the presence of oxygen, would generate ___________________ calories of heat energy.

• However, cells don’t “burn” glucose. Instead, they ____________________

release the energy from glucose and other food compounds. o This process is called _____________________

____________________________.

2

Cellular respiration takes place in the _______________________________.

Both _________________ and ____________________ cells carry out the process of cellular respiration in the mitochondria. Label the diagram of a mitochondrion below:

!!!!!!!!!!! Overview of Cellular Respiration: There are three stages that make up cellular respiration:

1. _______________________________________ 2. _______________________________________ 3. _______________________________________

What is cellular respiration?

Cellular respiration is the process that releases _____________________ by

breaking down _______________________ and other food molecules in the

presence of _______________________.

!

!

!

!

3

The equation for cellular respiration is:

oxygen + glucose carbon dioxide + water + energy What do you notice about this chemical equation? Hint: think back to photosynthesis! Each of the three stages of cellular respiration captures some of the _____________________ energy available in food molecules and uses it to produce _____________.

• Remember that ATP is the cell’s basic _________________ source. Refer to the diagram of cellular respiration above.

• Glycolysis takes place in the _____________________________. • The Krebs cycle and the electron transport chain take place in the

_________________________________.

!