Respiration

Learning Objectives Distinguish between respiration, ventilation and gaseous exchange. Outline the use of ATP as the energy currency in living things. Outline the process of aerobic respiration. Define and explain OXYGEN DEBT. Distinguish between aerobic and anaerobic respiration. Determine the energy in foods. Predict the outcome of experiments using hydrogen carbonate indicator.

Definitions RESPIRATION Gaseous Exchange Ventilation Respiration (which is often confused with breathing) is a set of chemical reactions that takes place in all living cells. It is the means by which we obtain useful energy from the food that we eat. Energy is produced in the form of ATP. The overall equation is: C6H12O6 + 6O2 → 6CO2 + 6H2O Gaseous exchange is the intake of oxygen and the excretion of carbon dioxide and water. This takes place across a respiratory surface. In humans, this is the lungs, or more specifically, the alveoli. In fish, it is the gills. In earthworms, it is the skin. In plants, the main respiratory surface are the leaves. Ventilation is where the stale air, containing a lower concentration of oxygen and a higher concentration of carbon dioxide , is expelled and replaced with fresh air containing higher concentrations of oxygen and lower concentrations of carbon dioxide. This maintains the concentration gradient across respiratory surfaces.

ATP Energy is used to add phosphates Energy is released when phosphates are lost Some energy Little energy Lots of energy

Aerobic Respiration Glucose Pyruvate 2ATP 36ATP CO2 H2O O2 Glycolysis in the cytoplasm 2ATP 36ATP Kreb’s cycle in the mitochondrion CO2 H2O O2 Where is most of the ATP produced? What are the two main stages of respiration? Which stage requires oxygen? What waste substances are produced? What is the total number of ATPs that can be made in respiration? What is meant by aerobic? Why do muscle cells contain a large number of mitochondria?

Anaerobic respiration (Animals) 2

Oxygen Debt Oxygen debt – the extra volume of air needed to break down the lactic acid Why does the oxygen consumption increase during vigorous exercise? (4) Why do sprinters only race up to 400 metres? (1) Why do they continue to breath heavily after they have finished running? (2)

Learning objectives Outline the process of anaerobic respiration in animals and fungi (yeast).

Anaerobic respiration (plants and yeast)

Compare aerobic and anaerobic respiration in humans Amount of ATP per glucose Site of reaction Use of oxygen End products

Show me quiz! 1 What is respiration? A breathing B a chemical reaction

Show me quiz! 1 B a chemical reaction

Show me quiz! 2 What is the energy currency within living things?

Show me quiz! 2 ATP

Show me quiz! 3 How many ATPs are made in glycolysis?

Show me quiz! 3 2

Show me quiz! 4 Name the stage of respiration that takes place in the mitochondrion

Show me quiz! Kreb’s Cycle 4

Show me quiz! 5 What is the maximum number of ATPs produced from one molecule of glucose?

Show me quiz! 38 5

Show me quiz! 6 Name the substance produced in muscles through anaerobic respiration

Show me quiz! Lactic acid 6

Show me quiz! 7 State the “SI” unit used to measure the amount of energy in foods

Show me quiz! Joule 7

Show me quiz! 8 Name the products of anaerobic respiration in yeast

Show me quiz! Ethanol and carbon dioxide 8

Show me quiz! 9 Name the apparatus used to accurately determine the energy content of foods

Show me quiz! Bomb calorimeter 9

Show me quiz! 10 State the term used to for the need for extra oxygen to break down lactic acid

Show me quiz! Oxygen debt 10

Show me quiz! 11 Name the proteins that control the reactions of respiration

Show me quiz! 11 Enzymes

12 Show me quiz! Which process requires ATP A Diffusion B Osmosis C Active transport

Show me quiz! 12 C Active transport

Hydrogen Carbonate Indicator A bicarbonate indicator (hydrogencarbonate indicator) is a type of pH indicator that is sensitive enough to show a color change as the concentration of carbon dioxide gas in an aqueous solution increases. Carbon dioxide produces a weak acid in solution. High Medium Low

Hydrogen Carbonate Indicator Draw and predict the colour of the hydrogen carbonate indicator in each tube High Medium Low

Determining the energy in foods CALORIMETRY Determining the energy in foods Haileybury Astana IGCSE Science

Learning Objectives Determine the amount of energy in foods. Identify the sources of error. State that fatty foods are higher in energy value

Calorimetry Energy = change in temperature x 25cm3 x 4.2J Weigh the food Measure out 25ml of water Measure the starting temperature of the water Ignite the food Place the burning food beneath the test tube of water Measure the temperature at the end Use the formula to determine the energy content of the food Food Mass Start temperature End temperature Change in temperature Energy = change in temperature x 25cm3 x 4.2J Mass of the food` Error analysis: Are the values too high or too low? List the sources of error.

Calorimetry Energy = change in temperature x 25cm3 x 4.2J Food Mass (g) Start temperature °C End temperature Temperature rise Energy J/g Crispbread Hazelnut Walnut Pecan Brazil Energy = change in temperature x 25cm3 x 4.2J Mass of the food` Error analysis: Are the values too high or too low? List the sources of error.

Data Nutrients Nut Variety Calories (kcal) Protein (g) Total Fat (g) Saturated Fat (g) Carbs (g) Fiber (g) Brazil Nuts 190 4 19 3 2 Hazelnuts 180 17 1.5 5 Pecans 200 20 Walnuts 18

Bomb Calorimeter