By the end of the topic, the learner should be able to:
In the mitochondria.
In the cytoplasm.
Carbon dioxide and water.
Ethanol in plants and lactic acid in animals.
38 molecules of ATP (2880 KJ) from each molecule of glucose.
2 molecules of ATP 210 KJ from each molecule of glucose.
No further reactions on carbon dioxide and water.
Ethanol and lactic acid can be broken down further in the presence of oxygen.
Comparison between Energy Output in Aerobic and Anaerobic Respiration
- Aerobic respiration results in the formation of simple inorganic molecules, water and carbon (IV) oxide as the byproducts.
- These cannot be broken down further. A lot of energy is produced.
- When a molecule of glucose is broken down in the presence of oxygen, 2880 KJ of energy are produced (38 molecules of ATP).
- In anaerobic respiration the by products are organic compounds.
- These can be broken down further in the presence of oxygen to give more energy.
- Far less energy is thus produced.
- The process is not economical as far as energy production is concerned.
- When a molecule of glucose is broken down in the absence of oxygen in plants, 210 KJ are produced (2 molecule ATP).
- In animals, anaerobic respiration yields 150 kJ of energy.
Substrates for Respiration
Lipids i.e. fatty acids and glycerol are also used.
Fatty acids are used when the carbohydrates are exhausted.
A molecule of lipid yields much more energy than a molecule of glucose.
Proteins are not normally used for respiration.
However during starvation they are hydrolysed to amino acids, dearnination follows and the products enter Kreb's cycle as urea is formed.
Use of body protein in respiration result to body wasting, as observed during prolonged sickness or starvation.
The ratio of the amount of carbon (IV) oxide produced to the amount of oxygen used for each substrate is referred to as Respiratory Quotient (RQ) and is calculated as follows:
Respiratory quotient value can thus give an indication of types of substrate used.
Besides values higher than one indicate that some anaerobic respiration is taking place.
Application of Anaerobic Respiration in Industry and at Home
- Making of beer and wines.
- Ethanol in beer comes from fermentation of sugar (maltose) in germinating barley seeds.
- Sugar in fruits is broken down anaerobically to produce ethanol in wines.
- In the dairy industry, bacterial fermentation occurs in the production of several dairy products such as cheese, butter and yoghurt.
- In production of organic acids e.g., acetic acid, that are used in industry e.g., in preservation of foods.
- Fermentation of grains is used to produce all kinds of beverages e.g., traditional beer and sour porridge.
- Fermentation of milk.
respiration audio visuals
- Explain the roles of enzymes in respiration
- What is aerobic respiration
- Give a word equation for aerobic respiration
- What are the end products of aerobic respiration?
- What are obligate anaerobes?
- What are facultative anaerobes?
- State the word equation representing anaerobic respiration in plants
- Name the end products of anaerobic respiration in plants
- Give a word equation of anaerobic respiration in animals
- Name the end products of respiration in animals when there is insufficient oxygen supply
- Why is there a high rate of lactic acid production during exercise?
- Why does lactic acid level reduce after exercise?
- State why accumulation of lactic acid during vigorous exercise lead to an increase in heartbeat
- State the economic importance of anaerobic respiration
- What is oxygen debt?
- What is respiratory quotient (RQ)?
- Why are respiratory quotient important
- Name the respiratory substrates
- Why does anaerobic respiration of a given substrate yield a smaller amount of energy than aerobic respiration?
- Explain the disadvantages of anaerobic respiration
- Mention the types of experiments carried out for respiration
- Define the following terms
- Explain why excretion is necessary in plants and animals
- Describe how excretion takes place in green plants
- Why do plants lack complex excretory structures like those of animals?
- State the excretory products of plants and some of their uses to humans
- Describe excretion in unicellular organisms
- List excretory organs and products of mammals
- Draw and label a mammalian skin
- Explain how the mammalian skin is adapted to its functions
- What is the role of lungs in excretion?
- State the functions of the liver
- Draw a labeled diagram of mammalian nephrone
- Describe how the human kidney functions
- Name the common kidney diseases
- Why is homeostatic control necessary?
- What is internal environment?
- Why is constant body temperature maintained by mammals?
- Explain the advantage gained by possessing a constant body temperature
- How do mammals regulate body temperature?
- Why does body temperature of a healthy person rise up to 37oC on a hot humid day?
- Name the structures in the human body that detect external temperature changes
- State the advantages that organisms with small surface area to volume ratio experience over those with larger
- Explain why individuals with smaller sizes require more energy per unit body weight than those with larger sizes.
- What is the meaning of osmoregulation?
- State the importance of osmoregulation
- State the ways by which desert mammals conserve water
- Explain why some desert animals excrete uric acid rather than water
- Explain why eating a meal with too much salt leads to production of a small volume of concentrated urine
- Explain how marine fish regulate their osmotic pressure
- What is the biological significance of maintaining a relatively constant sugar level in a human body?
- Discuss the role of the following hormones in blood sugar control
- Explain the part played by antidiuretic hormone in homeostasis
- What is the role of blood clotting in homeostasis?
- Describe the role of the following hormones in homeostasis
- Distinguish between diabetes mellitus and diabetes insipidus
- How can high blood sugar level in a person be controlled?
- Why does glucose not normally appear in urine even though it is filtered in the mammalian Bowman’s capsule?
- How would one find out from a sample of urine whether a person is suffering from diabetes mellitus?
BIOLOGY FORM 3 NOTES
EXCRETION AND HOMEOSTASIS
Gaseous Exchange In Animals
GASEOUS EXCHANGE IN PLANTS AND ANIMALS
INTRODUCTION TO BIOLOGY
NUTRITION IN ANIMALS
NUTRITION IN PLANTS AND ANIMALS
Transport In Animals
TRANSPORT IN PLANTS AND ANIMALS
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