C1.2. Cell respiration

Answer the question:

• A

• B

• C

• D

Answer explanation

The correct answer is A as the fluid will move in the direction of the tube with the organism in.

This is because the organisms are respiring aerobically, utilising oxygen and releasing carbon

dioxide as a metabolic 'waste' product. The carbon dioxide gas is absorbed by the

potassium hydroxide (KOH) which decreases the yolume of gas in the system. The liquid wil

move towards the lower volume of gas in order to equalise the pressure

Answer the question:

• A

• B

• C

• D

Answer explanation

When ATP (adenosine triphosphate) is converted to ADP (adenosine diphosphate), a phosphate group is removed, and energy is released. Reaction is reversible, phosphate group is removed not added, and energy is definitely not destroyed, but released and used by cell.

The rate of oxygen consumption was compared in yeast cells incubated with

and without glucose at three different temperatures under aerobic conditions.

The yeast cells were incubated for a period of 3 minutes during which the rate

of O2 consumption was measured with an O2 sensor.

• A

• B

• C

• D

Answer explanation

The graph shows that yeast uses much more oxygen with glucose at 55°C, so glucose is broken down faster at higher temperatures.

Answer the question:

• A

• B

• C

• D

Answer explanation

Anaerobic respiration produces lactic acid aka lactate in animal organisms and CO2. It doesn't oxidized glucose completely, and it takes place in cytoplasm, not mitochondria

Answer the question:

• A

• B

• C

• D

Answer explanation

The tubes contain an alkali such as sodium hydroxide to absorb any carbon dioxide given off during respiration. To ensure that any volume changes measured in the experiment are due to oxygen uptake only.

Answer the question:

• A

• B

• C

• D

Answer explanation

ATP is not stable molecule and it isn't transported between cells

Some students were investigating the production of carbon dioxide from

anaerobic respiration in yeast at different temperatures. They had access to

the apparatus to carry out two different methods.

• A

• B

• C

• D

Answer explanation

C is correct. With scale they will be able to get precise measurements

ATP is a chemical substance generated in cellular respiration; it is an immediate

source of energy for the cell. ATP can easily be hydrolysed or re-synthesised

State two products created when ATP is hydrolysed by water. [2]

Cells hydrolyse ATP to provide energy for other reactions, or to add phosphate

to other substances to make them more reactive. However, ATP needs to be

re-synthesised to provide energy for future reactions

Describe how ATP may be re-synthesised. [2]

Give two ways in which the properties of ATP make it a suitable source of

energy for biological processes. [2]