Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

Cell respiration

Topic 8
...
2

Results in a compound with lower

Biology HL

Results in a compound with higher

potential energy

potential energy

➢ The reduced form of a molecule always has more potential energy than the oxidized
form of the molecule
➢ Redox reactions play a key role in the flow of energy through living systems
○

Because the electrons that are flowing from one molecule to the next are
carrying energy with them

Example:

C6H12O6 + 6O2 ⇒ 6CO2 + 6H2O + energy
○
○

C6H12O6 was oxidized since it lost hydrogen atoms to form carbon dioxide
6O2 was reduced since it gained hydrogen atoms to form water

Glycolysis
➢ Uses no oxygen and occurs in the cytoplasm
○

No organelles are required

○

It proceeds efficiently in both aerobic and anaerobic environments

➢ Occurs in both prokaryotic and eukaryotic cells
➢ Steps:
○

Two molecules of ATP are used to begin glycolysis
■

The phosphates from the ATPs are added to glucose to form another
sugar

○

Less stable molecule

●

The process is called phosphorylation

The less stable 6-carbon sugar is split into two 3-carbon sugars
■

○

●

This splitting process is known as lysis

These sugars enter an oxidation phase involving ATP formation and the
production of the reduced coenzyme NAD
■

Each of those phosphate molecules undergoes oxidation to form a
+

reduced NAD which becomes NADH
●

Energy is released and it is used to add an inorganic
phosphate to the 3-carbon compound

○

Enzymes remove the phosphate groups so that they can be added to ADP to
produce ATP

2

Cell respiration

Topic 8

---