Starter: What do we need to make these?

Anaerobic respiration Objectives: Recall the anaerobic respiration equation. Describe the process of anaerobic respiration. Describe animal, plant and microbial cell structures and how they are involved in respiration.

Starter: T or F? (5min) All living things respire. Aerobic respiration requires oxygen and occurs in the cytoplasm. Respiration breaks down glucose quickly to make as much energy as possible Energy made in respiration can be used to make polymers like glucose and cellulose.

What happens when there is no oxygen? Anaerobic respiration (in animals) Glucose  lactic acid + energy (ATP) What situations occur where there is little or no oxygen? When the body (i.e. muscles) cannot get oxygen quick enough

Anaerobic respiration in animals Toxic!! Run for your life!!! Why might animals respire anaerobically?

Anaerobic respiration in plants Waterlogged roots Yeast – brewing and baking Lactobacilli – cheese / yoghurt When would a plant respire anaerobically?

Plants, yeast, and bacteria….

Are there alternatives? Bioethanol Are there alternatives?

Yeast are used to make bioethanol on a large scale from sugar Bioethanol from sugar Yeast are used to make bioethanol on a large scale from sugar

Task Draw the diagram and use it to help you explain the process of fermentation in yeast

Remember sustainability? Explain in your own words what is controversial with the production of biofuels?

Break down organic material in manure Biogas bacteria To produce methane Break down organic material in manure

Biogas too! YUM!!! MEGA yum!!

Copy the diagram Draw a flow chart to show how energy is transferred starting with the sun and ending with the conversion of methane in biogas. Explain and label each stage.

How will we rebuild society? Plenary The end has come! Humanity as you know it is changed forever. There is no going back. Your unsustainable lifestyle has brought the end. The only resources left are: A few pigs Some plants Bacteria Containers Stationary How will we rebuild society?

Homework Hint: we BURN the methane Extension: Draw the chemical formula for this reaction

Why do seals use anaerobic respiration on deep sea dives?

Aerobic vs. anaerobic respiration Equation Glucose + oxygen  carbon dioxide + water + energy Glucose  lactic acid + energy (animals) Glucose  ethanol + carbon dioxide + energy (plants, yeast, bacteria) Where does it occur? Mitochondria Cytoplasm Advantages Produces a lot of energy Can quickly produce energy Doesn’t need oxygen Disadvantages Requires oxygen to occur Short-lived Produces less energy Produces the toxin lactic acid in animals In what situations does it occur? Energy made is used to fuel polymer synthesis, chemical reactions, active transport in all living organisms Situations that require short bursts of energy (i.e. sprint, being chased by predator) Used to make beer, bread, yoghurt and cheeses

Check your answers Give an example of anaerobic respiration that people draw on to make a useful product. Any suitable example, e.g. Lactobacilli used in cheese and yogurt production or yeast in brewing and bread making or methane producing bacteria in a biogas plant. (Note: The production of soya sauce involves two stages, one aerobic and one anaerobic. The production of vinegar is an aerobic process.) Yeast is used in brewing to make alcoholic drinks. Suggest why the yeast stops growing and dies before it has used up all the sugar in the fermentation solution. Anaerobic respiration in yeast produces alcohol (ethanol). This is toxic. As fermentation progresses, the alcohol builds up and eventually kills the yeast.

Exam Practice (back of book) (a) Five biology students were talking about respiration. These are the statements they made. Tick () the correct statements. Respiration makes energy in cells. Respiration releases energy for growth. Glucose is broken down releasing energy. Respiration only happens in animals. Respiration can be with or without oxygen.

Answers a) b) 3 correct = 2 marks 2 correct = 1 mark Respiration makes energy in cells. Respiration releases energy for growth.  Glucose is broken down releasing energy. Respiration only happens in animals. Respiration can be with or without oxygen. 3 correct = 2 marks 2 correct = 1 mark None or 1 correct = 0 marks b) Movement needs energy from respiration [1] Respiration is faster in warm temperatures because the enzymes work faster. [1]