Anaerobic Respiration

What happens when there isn’t enough oxygen to accept the H+ and e-?

Pyruvic acid

Glucose

Carbon dioxide + water

Glycolysis2 ATP

Krebs and ETC36 ATP

Aerobic Respiration

Glucose + oxygen carbon dioxide + water + ATP

C6H12O6 + 6O2 + 38 ADP + 38 Pi 6 CO2 + 6 H2O + 36 ATP

Pyruvic acid

Glucose

2 ATP

Anaerobic Respiration

No oxygen as final H+ / e- acceptor

e- transport and Krebs cycle stop

pyruvate buildup

Pyruvic acid

Glucose

Lactic acid

2 ATP

Anaerobic respiration

In animals

Typically occurs in animals during prolonged exercise.

Lactic acid causes muscle fatigue

Pyruvic acid

Glucose

Ethanol + Carbon dioxide

2 ATP

Anaerobic Fermentation in yeast & bacteria

Normal way of life.

Carbon dioxide release causes the bubbles in bread and beer

Plenty of oxygen Aerobic respiration

Lots of ATP

Low oxygen anaerobic respiration

less ATP

↑energy requirements ↑ increase respiration rate ↑ oxygen demand & ↑ CO2

↑ breathing rate

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Key Words

Exercises

Quick Quiz

MCQ

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Key words

• ATP• glycolysis• glucose• pyruvate• final acceptor• lactic fermentation• yeast fermentation• anaerobic

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QUICK QUIZ1. ____ respiration occurs in the absence of sufficient oxygen

2. Yeast undergoes ____ under anaerobic conditions

3. Animals produce ____ under anaerobic conditions

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Answers

QUICK QUIZ1. anaerobic respiration occurs in the absence of sufficient oxygen

2. Yeast undergoes fermentation under anaerobic conditions

3. Animals produce lactic acid under anaerobic conditions

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Exercise

• Workbook pp 67-72, all questions• Pathfinder p45 q5

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READING• Pathfinder p43• Excellence in Biology 126-130

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Question 1

When living cells break down molecules, energy is

a. stored as ADP

b. released as heat

c. stored as ATP

d. Both b and c 

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Question 2

In cellular respiration, the most ATP is made during

a. glycolysis

b. lactic acid fermentation     

c. the Krebs cycle      

d. electron transport chain 

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Question 3

The breakdown of sugars to produce ATP and ethanol is known as

a. respiration 

b. alcoholic fermentation  

c. lactic-acid fermentation  

d. photosynthesis 

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Question 4

Which of the following is not formed during Cellular Respiration?

a. Oxygen                        

b. ATP

c. CO2  

d. Water 

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Question 5

Which of the following is never part of cellular respiration?

a. Fermentation         

b. the Krebs cycle       

c. glycolysis                

d. the Calvin cycle 

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Question 6

With enough oxygen present which of the following does not occur?

a. glycolysis.          

b. aerobic respiration 

c. fermentation         

d. All of the above 

 

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Question 7

An important molecule generated by both lactic acid and alcoholic fermentation is

a. ATP                       

b. CO2                     

c. NADH                        

d. NAD+

 

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Question 8

Glycolysis takes place _____

a. in all cells 

b. only if oxygen is present

c. without oxygen

d. only if oxygen is absent 

 

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Question 9

Yeast cells produce alcohol and CO2 in the process of _________

a. lactic acid fermentation   

b. glycolysis

c. aerobic respiration   

d. alcoholic fermentation     

 

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Question 10

Glycolysis takes place in the ____________

a. chloroplast    

b. mitochondria              

c. cytoplasm               

d. nucleus  

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Question 11

Aerobic Respiration produces ____ molecules of ATP.

a. 34                         

b. 19                           

c. 2                  

d. 63 

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Question 12

Aerobic processes require _____ in order to take place.

a. sunlight               

b. oxygen                        

c. water               

d. carbon dioxide 

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Question 13

To maximize ATP production, glycolysis must be followed by

a. fermentation       

b. the Calvin cycle   

c. aerobic respiration      

d. photosynthesis 

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Question 14

When muscles are exercised extensively in the absence of sufficient oxygen

a. oxidative respiration   

b. ethanol is produced 

c. glucose     

d. lactic acid is produced 

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Question 15

What two organs do we store sugars in?

a. muscles & heart   

b. Liver & muscles  

c. stomach & intestines  

d. brain & spine  

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Correct

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Incorrect

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