The process in which cells use oxygen to burn sugar for fuel.

 The word aerobic means “requiring air” but the only important component of air, as far as respiration is concerned, is the gas oxygen, which makes up approximately 20% of the total.

 We will measure the amount of oxygen taken in by dry peas and germinating peas during respiration at two different temperatures.

 A respirometer is an apparatus for measuring the amounts of gases used during respiration.

 Discuss the gas laws as they apply to the function of a respirometer  Interpret data related to the effects of temperature on cell respiration  Interpret data related to the effects of germination or non-germination on cell respiration  Explain or determine the significance of a control  Explain the relationship between dependent & independent variables  Calculate a rate of cell respiration by utilizing graphed data

 C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + 36ATP Glucose + Oxygen  Carbon Dioxide + Water + Energy (ATP)

 The fruit-ripening process may be greatly slowed down by using cold storage methods (refrigeration), which reduces the respiration rate of fruit.

 P is the pressure of the gas  V is the volume of the gas  n is the number of molecules of gas  R is the gas constant (fixed value)  T is the temperature of the gas  This gas law is important to the understanding of how the respirometer works

 If temperature and pressure are kept constant, then the volume of the gas is directly proportional to the number of molecules of the gas.  If the temperature and volume remain constant, then the pressure of the gas changes in direct proportion to the number of molecules of gas present.

 If the number of gas molecules and the temperature remain constant, then the pressure is inversely proportional to the volume.  If the temperature changes and the number of gas molecules is kept constant, then either the pressure or volume (or both) will change in direct proportion to the temperature.  Gases and fluids flow from regions of high pressure to regions of low pressure.

 Look at the Equation again: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + 36ATP  6 molecules of oxygen react and 6 molecules of carbon dioxide are produced – this is a problem, because we only want to measure amount of oxygen used by the peas

 We will use a chemical called potassium hydroxide (KOH) to convert carbon dioxide gas to a solid precipitate (K 2 CO 3 ).  This removes the gas produced & ensures that we are only measuring oxygen consumed by the peas.  DANGER: WEAR GOGGLES & DO NOT GET KOH ON YOUR SKIN!

 Potassium hydroxide (KOH), otherwise known as caustic potash, is used in making soaps, detergents, potassium carbonate and other potassium chemicals.

 Respirometers 1 – 3 will be placed in room temperature water  Respirometers 4 – 6 will be placed in ice water  Each lab group will be assigned to one temperature and will set up 3 respirometers

 Seeds are dormant stages of living organisms, and contain embryos.

 Respirometer 1 will contain germinating peas  Repirometer 2 will contain dry peas + glass beads (why add glass beads?)  Respirometer 3 will contain glass beads only

 It is necessary to keep the temperature within the respirometer stable so the enclosed gas does not expand or contract as in a thermometer.

 Hibernation is a form of adaptation where an animal’s respiration slows down to very low levels in response to cold temperatures. Common hibernators include woodchucks, hedgehogs, and shrews. Less commonly known are bats, whose respiration slows from eight breaths per second to eight breaths per minute during hibernation.

1 – Read through entire procedure (white portion of packet) 2 – You will work with your fermentation lab partners on this lab – try to answer the blue pre-lab questions (1 – 10) with your partners 3 – Make corrections as needed when we go over the pre-lab questions 4 – Be prepared to set up the lab and collect data on Wednesday.