Chapter 9 Section 1 Notes
Chemical Pathways
Name: ___________________________________ Date: _______________
Period: _____
Objectives:
 Explain what cellular respiration is.
 Describe what happens during the process of glycolysis.
 Name the two main types of fermentation.
Food:
 Food provides living things with the chemical building blocks they need to ______________ and
________________________.
 Food serves as a source of __________ ____________________ for the cells of the body.
 Most of all, food serves as a source of ______________.
Chemical Energy and Food:
 A ______________ is the amount of ___________ needed to raise the temperature of 1 gram of
water 1 degree Celsius.
 The Calorie (capital “C”) that is used on food labels is a kilocalorie, or _____________ calories.
 Cells gradually release the _____________ from ______________ and other food compounds.
 This process begins with a pathway called ___________________.
 Glycolysis releases only a ________________ amount of energy.
 If oxygen is _________________, glycolysis leads to __________ other pathways that release a
great deal of _______________.
 If oxygen is _________ ________________, however, glycolysis is followed by a different
pathway.
Overview of Cellular Respiration:
 In the _______________ of ________________, glycolysis is followed by the _______________
____________ and the ______________ ____________________ ________________.
 Glycolysis, the Krebs cycle, and the electron transport chain make up a process called
______________________ __________________.
Cellular Respiration is the process that releases ______________ by breaking down
________________ and other food molecules in the presence of ________________.
 Equation:
6O2 + C6H12O6
oxyen + glucose
6CO2 + 6H2O + Energy
carbon dioxide + water + energy
Glycolysis:
Glycolysis is the process in which ________ molecule of _____________ is broken in half,
producing ________ molecules of ___________ _________, a 3-carbon compound.
 ATP Production:
 Uses _____ molecules of ______
 Produces _____ molecules of __________
 NADH Production:
 The electron carrier, NAD+, or nicotinamide adenine dinucleotide, accepts a pair of highenergy _________________.
 This molecule, known as NADH, ________________ the electrons until they can be
______________ to other molecules.
 NAD+ helps to ______________ _____________ from _____________ to other
pathways in the cell.
Advantages and Disadvantages of Glycolysis:
 Advantages:
 The process is so fast that cells can produce thousands of _______ molecules in just a
few milliseconds.
 Does _______ require ____________.
 Disadvantages:
 In just a few seconds, all of the cell’s available NAD+ molecules are filled up with
_________________.
 Without NAD+, the cell cannot keep _____________ going, and ATP production
_________________.
Fermentation:
 When oxygen is ________ present, glycolysis is followed by a different pathway.
 The combined process of this pathway and glycolysis is called _______________________.
 Fermentation releases _______________ from food molecules by producing ______ in the
_____________ of oxygen.
 Cells convert NADH to NAD+ by passing high-energy electrons back to
_________________ _____________.
 Because fermentation does not require oxygen, it is said to be __________________
(“not in air”).
The two main types of fermentation are _________________ fermentation and ____________
________________ fermentation.
Alcoholic Fermentation:
 Equation:
pyruvic acid + NADH
alcohol + CO2 + NAD+
 __________________ and a few other microorganisms use alcoholic fermentation.
 Causes __________ to rise.
Lactic Acid Fermentation:
 In many cases, the pyruvic acid that accumulates as a result of glycolysis can be converted to
________________ _____________.
 Because this type of fermentation produces lactic acid, it is called lactic acid fermentation.
 Equation:
pyruvic acid + NADH
lactic acid + NAD+