Respiration Information

Question 1

What is ATP required for?

Answer 1

• Synthesis
• Transport (active)
• Movement

Question 2

What is the structure of ATP?

Answer 2

• An adenine base
• A ribose monosaccharide
• 3 phosphate groups

Question 3

How does ATP release energy?

Answer 3

It is hydrolyzed easily to remove a phosphate group and it forms an inorganic phosphate, ADP and energy

Question 4

Is ATP a good long-term energy store?

Answer 4

No, ATP is a good short-term energy store as it is unstable and can be hydrolyzed easily. Carbohydrates and fats are much better energy stores for the long term, whereas ATP is a great immediate energy store.

Question 5

Name the properties of ATP

Answer 5

• It’s small so can move in and out of cells easily
• It is soluble in water
• It releases immediate energy when broken down
• It releases energy in small quantities
• It can easily be regenerated

Question 6

Respiration equation

Answer 6

Glucose + Oxygen –> Carbon dioxide + Water

Question 7

What is respiration used for?

Answer 7

It synthesises ATP which is used as an energy store and allows metabolic reactions to take place

Question 8

Is respiration exothermic or endothermic?

Answer 8

It’s exothermic because the total energy required to break down the large organic molecules is less than the energy released when the smaller inorganic ion bonds form

Question 9

What is chemiosmosis?

Answer 9

This is the process of ATP synthesis. Protons diffuse from an area of high proton concentration to an area of low proton concentration through a partially permeable membrane and this causes a release of energy which is used to attach an inorganic phosphate to its ADP which is a condensation reaction. Excited electrons are needed to do this

Question 10

How do electrons become excited?

Answer 10

• Electrons present in pigment molecules absorb light from the sun and become excited.
• High energy electrons can also be released when chemical bonds are broken and they can be used to generate a proton gradient as they pass through an electron transport chain

Question 11

Explain the electron transport chain

Answer 11

The electron transport chain are electron carriers that have progressively lower energy and this exists within a membrane. The excited electrons will enter the electron transport chain and will release energy as they move from one electron carrier to another. This energy is used to pump protons from the outside of the membrane to the inside and generates a proton gradient. This gradient is maintained by the impermeability of the membrane

Question 12

Explain chemiosmosis using the electron transport chain

Answer 12

After the proton gradient has been made, the protons will naturally want to move down their concentration gradient again, so they have to pass through hydrophilic membrane channels which are linked to the enzyme ATP synthase. As the protons pass through this channel through facilitated diffusion, they release energy to the ATP synthase which can then catalyse the formation of ATP