Cellular Respiration And Metabolism

Question 1

What are the two classifications of molecular pathways ?

Answer 1

Anabolic: Amassing + building up. Requires energy . Process of creating more complex molecules from simple atoms.

Catabolic: Breaking down complex molecules into smaller molecules. Releases energy.

Question 2

What is the energy currency in the cell?

Answer 2

ATP.

However, amount of ATP is limited. Therefore the body recycles ATP from ADP.

Question 3

What is Metabolism?

Answer 3

Cells extract energy from their environment and use the energy for a number of biological activities.

Question 4

What are the basic principles that govern metabolism?

Answer 4

Molecules are synthesised in a series of reactions ( metabolic pathways)
ATP is the energy currency of life
ATP can be formed by the oxidation of carbon fuels
Metabolic pathways are highly regulated

Question 5

How does ATP help reactions to proceed?

Answer 5

ATP is an unstable molecule that wants to lose its phosphate groups. If the heat of the reaction ie Delta G is negative the reaction will proceed spontaneously = exergonic
If Delta G is positive the reaction will not proceed spontaneously = endergonic

ATP undergoes hydrolysis to form ADP.
ATP (+H2O) — ADP
This reaction releases energy. Cells than use the energy released ( exergonic) to power endergonic reactions therefore driving metabolism forward.

Question 6

How are enzymes used in Metabolism?

Answer 6

Enzymes bind to a substrate and catalyse the reaction.

phosphorylation (the transfer of a phosphate group from a molecule to a protein ) causes changed to the substrate making it more easily accessible to the enzyme.

Question 7

How are enzymes regulated?

Answer 7

Feedback inhibition: the product of the enzyme reaction inhibits the enzyme itself.

Question 8

Which processes would produce ATP from ADP?

Answer 8

Oxidation of fuel molecules+ photosynthesis

Question 9

What would produce ADP from ATP?

Answer 9

Active transport + Motion + Biosynthesis