Chemical Pathways

Chapter 9 Section 1

Name:___________________________________

Each of our bodies has a different way to let us know when we are hungry. Food serves as a source of raw materials from which

__________________________.

A calorie is the amount of energy needed to raise the temperature of ______________

___________________.

1 gram of sugar releases _______ calories of

heat energy.

The breakdown of food begins with the process called _______________________.

When we consume food, our bodies breakdown food__________________________________.

Click the image to play the video segment.

Video 2

Glycolysis

Video Chapter 9B.mpg

Glycolysis comes from the Greek word glukus meaning ____________ and the Latin word lysis means ______________________.

1st step of glycolysis

See animation of glycolysis

2nd step Splitting of Glucose

3rd Step of Glycolysis – Energy Generation

.

Glycolysis is the process in which one molecule of glucose is broken in half producing two molecules of ______________________.

• GLYCOLYSIS

• Happens in ______________ of cell

• Four electrons are passed to an electron carrier called _______________

• NAD+ accepts electrons to make

__________

• _______ is nicotinamide adenine dinucleotide.

HIGH ENERGY ELECTRONS require a special carrier, too

• ____________ is one• of the carriers that• cells use to transport• high energy electrons.

________ + _____ + _____ → ____________

_______= nicotinamide adenine dinucleotide

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GlucoseGlycolysis

Cytoplasm

Pyruvic acid

Electrons carried in NADH

Krebs Cycle

Electrons carried in

NADH and FADH2 Electron

Transport Chain

Mitochondrion

Figure 9–2 Cellular Respiration: An Overview

Mitochondrion

Section 9-1

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Glucose

To the electron transport chain

Figure 9–3 Glycolysis

Section 9-1

2 Pyruvic acid

•NADH holds the electron until _________________________________________.

• The energy yield from glycolysis is __________.

•The process is so fast that cells can produce thousands of ATP molecules in __________________. •Besides speed, glycolysis does _________________. •Without NAD+, the cell cannot keep glycolysis going, and ______________________________.

Following Glycolysis when oxygen is absent:

If oxygen is not present, a cell begins with glycolysis and continues with a different pathway called fermentation.

There are two types of fermentation:

•________________

•________________

During fermentation NADH converts to _________.

This is an ______________ process.

Alcoholic Fermentation

Used in bread production (leavened bread) uses yeast to raise the bread. Yeast uses sugar and gives off carbon dioxide. The alcohol generated cooks out of the bread when baking.

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Glucose Pyruvic acidLactic acid

Figure 9–4 Lactic Acid Fermentation

Section 9-1

Lactic Acid Fermentation

When you exercise vigorously by running/swimming, your muscle cells need oxygen. When there is not enough oxygen, your body can’t produce all the ATP that it needs. Your muscles begin to generate ATP by lactic acid fermentation. This buildup causes a painful burning sensation. This is why muscles feel sore or you get a side ache. You need to breathe to reverse the lactic acid fermentation to cellular respiration.

Lactic Acid Fermentation

Unicellular organisms produce lactic acid as a waste product during fermentation.

Prokaryotes (good bacteria) are used in the production of a wide variety of foods and beverages such as cheese, yogurt, buttermilk, sour cream, pickles, sauerkraut, and kimchi.

All of the above foods are produced using lactic acid fermentation.

Go to Section:

Glucose

Glycolysis Krebs cycle

Electrontransport

Fermentation (without oxygen)

Alcohol or lactic acid

Chemical Pathways

Section 9-1