Oxidative phosphorylation and respiratory quotientEdexcel International A Level Biology: Flashcards

What these 15 flashcards ask

Where is the electron transport chain?
What do reduced NAD and reduced FAD do at the electron transport chain?
What happens to the energy released as electrons pass along the chain?
What is the final electron acceptor?
What is chemiosmosis?
What does ATP synthase do?
Why does the inner mitochondrial membrane have cristae?
What happens to the electron transport chain without oxygen?
What is the respiratory quotient (RQ)?
Give the RQ values for carbohydrate, protein and lipid.
Why is the RQ of lipids lower than that of carbohydrates?
What is the RQ of anaerobic respiration?
What does potassium hydroxide do in a respirometer?
How do you calculate the volume of oxygen used in a respirometer?
What is the effect of an uncoupling agent?

Exam questions on Oxidative phosphorylation and respiratory quotient

Skeletal muscle cells make most of their ATP in mitochondria by oxidative phosphorylation. Electron micrographs show that the mitochondria of muscle cells have many more cristae than those of cells that are less active.
Explain why the mitochondria in muscle cells have many cristae.2 marks
A volunteer who had not eaten for three days breathed through a respirometer. The volunteer used 250 cm³ of oxygen and produced 190 cm³ of carbon dioxide each minute at rest.
Explain why the respiratory quotient for lipids is lower than that for carbohydrates.2 marks
A student investigates the respiration of 5 g of germinating pea seeds at 20 °C in two simple respirometers. In tube A the carbon dioxide is absorbed by potassium hydroxide solution. Tube B has no potassium hydroxide solution. The cross-sectional area of the capillary tube is 0.80 mm². In 10 minutes the coloured liquid in tube A moved 30 mm towards the seeds, and in tube B it moved 6 mm towards the seeds.
Explain what the movement of the liquid in tube A measures and calculate the rate of this process in mm³ per minute.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).