Respiration

Question 0

What are the 4 stages of aerobic respiration?

Answer 0

1. Glycolysis 2. The link reaction

3. Kerbs cycle 4. Oxidative phosphorylation

Question 1

Describe the structure of ATP

Answer 1

A molecule of adenine attached to a the 5 carbon sugar ribose. A chain of 3 phosphate molecules are attached to the other side of the ribose

Question 2

Why are coenzymes needed?

Answer 2

Because normal enzymes are not very good at catalysing oxidation or reduction equations, coenzymes must be used to catalyse them for respiration

Question 3

What are the steps, required substances and products of glycolysis?

Answer 3

(Glucose -> glucose-6-P -> fructose-1-P -> Hexose 1,6-bisphosphate) -> (2xtrios phosphate) -> (2xintermediate compound) -> (2xpyruvate)
1 ATP is put in at the first and third arrow. 2 ATP molecules come out at the 5th and 6th arrows. 2 reduced NADP molecules are also produced at the 5th arrow

Question 4

What are the different parts of the mitochondria?

Answer 4

Inner membrane/cristae, outer membrane, matrix, intermembrane space, ATP synthase

Question 5

Explain the function of the inner mitochondrial membrane

Answer 5

It houses electron transport chains made up of electron carriers. Some of the electron carriers use energy from the electrons to pump protons into the intermembrane space creating a proton gradient which is used by the. ATP synthase to create ATP from ADP and Pi

Question 6

Describe the link reaction

Answer 6

Pyruvate—>(reduces NAD) + CO2 + acetyl CoA—>acetate and CoA

Question 7

Describe the kerbs cycle

Answer 7

Acetate + oxyloacetate –> citrate –> 5c compound (CO2 and reduces NAD) –> 4c compound (CO2 and reduces NAD)–> 4c compound (ATP) –> 4c compound (reduces FAD) –> oxyloacetate (reduces NAD)

Question 8

Describe the process of chemiosmosis and oxidative phosphorylation

Answer 8

As electrons flow along the electron transport chain energy is released and used to pump protons across the intermembrane space, this builds up a proton gradient, a pH gradient and an electrochemical gradient. Thus, potential energy builds up. The protons are forced to diffuse down the proton gradient through ion channels associated with ATP synthase. As protons flow through this channel they drive the rotation of part of ATP synthase to create ATP from ADP and Pi. The electrons are passed from the last electron carrier to oxygen, the hydrogens also bond to this oxygen making water.

Question 9

Describe lactate fermentation

Answer 9

Pyruvate —> lactate

This uses 2 hydrogens from reduced NAD and is catalysed by lactate dehydrogenase

Question 10

Describe the process if alcohol fermentation

Answer 10

Pyruvate –> ethanal –> ethanol
Creating CO2 and using 2H from reduced NAD. The first step is catalysed by pyruvate decarboxylase and the second by ethanol dehydrogenase