(2.34-2.39) Respiration- aerobic + anaerobic, practicals

What is respiration?

A chemical reaction that occurs in all living organisms.

How is energy released from respiration?

It is released from glucose and is transferred in the form of ATP.

What is ATP?

Adenosine Triphosphate:

A molecule produced in respiration in the mitochondria that is a source of energy for cells and can be recycled.

What do organisms need energy for?

Chemical reactions

Movement

Thermoregulation

What is cellular respiration?

An exothermic reaction that releases energy from glucose.

What is aerobic respiration?

The chemical reaction in cells that uses oxygen to completely break down glucose to release a relatively large amount of energy.

What are waste products of aerobic respiration?

Carbon dioxide and water

What is the word equation for aerobic respiration?

Glucose + Oxygen → Carbon Dioxide + Water + ATP

What is the balanced chemical equation for aerobic respiration?

C6H12O6 + 6O2 → 6CO2 + 6H20

What is anaerobic respiration?

The chemical reaction in cells that incompletely breaks down glucose to release a relatively small amount of energy without oxygen.

When is anaerobic respiration used in animals?

When oxygen demands of aerobic respiration aren’t met, muscle cells use anaerobic respiration.

Describe anaerobic respiration in animals.

At a slower speed and releasing less energy than aerobic respiration,

glucose is broken down without oxygen,

releasing lactic acid

which builds up in muscles causing pain + cramps.

What is the balanced chemical equation for anaerobic respiration in animals?

C6H12O6 → 2C3H6O3

What is EPOC?

Excess Post-exercise Oxygen Consumption

What is oxygen debt?

The oxygen later used to break down the lactic acid that has built up in muscle cells.

Describe the process of anaerobic respiration in plants and fungi.

The breakdown of glucose to produce ethanol and carbon dioxide.

What is the balanced chemical equation for the anaerobic respiration in plants?

C6H12O6 → 2C2H5OH + 2CO2

Detail the investigation to determine the evolution of carbon dioxide from respiring seeds.

1. Measure out 10cm³ of hydrogen-carbonate indicator into 3 boiling tubes.

2. Insert a layer of cotton wool.

3. Put 10 germinating seeds in A, 10 boiled/dead seeds in B and 10 glass beads in tube C.

4. Seal each tube with a rubber bung.

5. Observe the colour of the indicator after a set amount of time.

Hydrogen-carbonate indicator is

— in atmospheric levels,

— in high CO2 levels,

— in low CO2 levels.

orange

yellow

purple

What results should we see in the seed CO2 experiment + why?

• Tube A with germinating seeds should turn —.

• Tube B with dead seeds should turn —-.

• Tube C with glass beads should turn —-.

yellow- seeds are respiring.

orange- no CO2 production.

orange- no living material.

Detail the investigation to determine the evolution of heat from respiring seeds.

1. Set up Flask A with dead seeds and B with germinating seeds. Insert thermometer and plug top with cotton wool.

2. Invert the flask so the seeds are surrounding the thermometer and record the initial temperature.

3. Record the final temperature after a set time. (few days)

What result should be visible in the seed heat experiment?

Thermometer in germinating seed flask should increase in temperature as the respiring seeds produce heat energy.

Thermometer in dead seed flask should remain the same as dead seeds do not respire.