ATP Flashcards
What enzyme catalyses the breakdown on ATP?
ATP hydrolase enzyme
How can inorganic phosphate (released by breakdown of ATP) be used?
It can be used to phosphorylate another compound/ added to another compound, which often makes the compound more reactive.
The movement of calcium ions across a cell membrane can occur via the energy-requiring process of active transport.
This movement of calcium ions is coupled to the breakdown of ATP.
Suggest why.
The breakdown/hydrolysis of AT releases energy, so when this reaction/hydrolysis is coupled to the process of active transport it provides the energy for this process directly.
ATP is an energy source used in many cell processes. Give two ways in which ATP is a suitable energy source for cells to use.
2 marks
Releases relatively small amount of energy / little energy lost as
heat;
(Key concept is that little danger of thermal death of cells)
Releases energy instantaneously;
Key concept is that energy is readily available
Phosphorylates other compounds, making them more reactive;
Can be rapidly re-synthesised;
Is not lost from / does not leave cells.
Cells constantly hydrolyse ATP to provide energy.
(a) Describe how ATP is resynthesised in cells.
2 marks
From ADP and phosphate;
- By ATP synthase;
- During respiration/photosynthesis
Scientists investigated treatment of a human bladder infection caused by a species of bacterium. This species of bacterium is often resistant to the antibiotics currently used for treatment.
They investigated the use of a new antibiotic to treat the bladder infection. The new antibiotic inhibits the bacterial ATP synthase enzyme.
The new antibiotic is safe to use in humans because it does not inhibit the
ATP synthase found in human cells.
Suggest why human AT synthase is not inhibited and bacterial synthase is inhibited.
1 mark
Human ATP synthase has different teriary structure to bacteria ATP synthase
Human ATP synthase has a different shape active site to bacterial ATP synthase
Antibiotic cannot enter human cells/mitochondria
Antibiotic not complementary (to human ATP synthase);
What are ATP component molecules
Adenine
Ribose
3 phosphates
Give two ways in which hydrolysis of ATP is used in cells
2 marks
- To provide energy for other reactions/named process;
Reject ‘produce’ energy - To add phosphate to other substances and make them more reactive/change their shape;
Suggest and explain a procedure the scientists could use to stop the reaction. When investigating effect of concentration of Pi on ATP synthesis activity?
2 marks
Mark in pairs - eg. 1 and 2 = 2marks
- Boil or add strong acid/alkali
- Denatures ATP synthase
- Put in ice/fridge/freezer
- Lower kinetic energy so no enzyme substrate complex formed
- Add high conc of inhibitor
- Esc do not form
What happens if you increase concentration of Pi
More enzyme substrate complex’s are formed = increase ATP concentration
Hydrolysis of ATP is catalysed by the enzyme ATP hydrolase.
A student investigated the effect of ATP concentration on the activity of ATP hydrolase.
She used shortening of strips of muscle tissue caused by contraction as evidence that ATP was being hydrolysed.
- She took four slides A, B, C and D, and added strips of muscle tissue of the same length to each slide.
- She then added the same volume of ATP solutions of different concentrations to the four slides and left each slide for five minutes.
- She then recorded the final length of each strip of muscle tissue.
Q) other than those given, name 2 variables the student should have controlled
2 marks
- Species / organism the muscle tissue came from;
OR
Thickness / type / source of the muscle tissue;
Ignore surface area of muscle tissue
————————
- Temperature of the muscle tissue / ATP solution / slides;
Need to be qualified
———————-
- pH of the ATP solution;
Need to be qualified
Reject concentration / volume of ATP hydrolase
Hydrolysis of ATP is catalysed by the enzyme ATP hydrolase.
A student investigated the effect of ATP concentration on the activity of ATP hydrolase. She used shortening of strips of muscle tissue caused by contraction as evidence that ATP was being hydrolysed.
- She took four slides A, B, C and D, and added strips of muscle tissue of the same length to each slide.
- She then added the same volume of ATP solutions of different concentrations to the four slides and left each slide for five minutes.
- She then recorded the final length of each strip of muscle tissue.
Describe and explain the pattern shown in the data in the table. 2 marks
The data shows as conc of ATP increases the length of muscle decreases
Description
1. As concentration of ATP increases, length of muscle decreases;
Accept negative correlation
——————————————————
Explanation
2. More ATP (hydrolysed by ATP hydrolase), so more energy released, so more muscle contraction / shortening of muscle;
Accept more ATP available for correct/named aspect of muscle contraction
