Chapter 12 - Respiration Flashcards
What is aerobic respiration?
Respiration in plentiful supplies of oxygen
What is anaerobic respiration?
Respiration where oxygen supplies are limited
Products of aerobic respiration
Carbon dioxide, water and ATP
Products of anaerobic respiration
Lactate and a little ATP
What are the four stages of respiration?
Glycolysis
The Link reaction
The Krebs cycle
Oxidative phosphorylation
General description of glycolysis
6C glucose splits into 2x 3C pyruvate
General description of the Link reaction
2C Acetylcoenzyme A is formed from the 3C pyruvate
General description of the Krebs cycle
ATP, FAD and NAD are produced through the oxidation and reduction of acetylcoenzyme A
General description of oxidative phosphorylation
The use of electrons to synthesise ATP and water
Where does glycolysis occur?
Cytoplasm
What happens during glycolysis?
Two ATP molecules are hydrolysed into ADP and P
These phosphate molecules phosphorylate the glucose, making it more reactive
The glucose molecule is split into two molecules of triose phosphate
Triose phosphate is oxidised and this hydrogen reduces a hydrogen carrier called NAD
The triose phosphate molecules are converted into 2 molecules of 3C pyruvate
This process also regenerates 2 molecules of ATP
What happens to the pyruvate during anaerobic respiration?
It is converted into ethanol in plants and yeast or lactate in animals using reduced NAD
What are the overall products from glycolysis?
2 molecules of ATP
2 molecules of reduced NAD
2 molecules of pyruvate
Does glycolysis require oxygen?
No
What happens during the link reaction?
The pyruvate is oxidised to form acetate
It loses one carbon dioxide molecule and two hydrogen atoms
These hydrogen atoms are accepted by the NAD, reducing it
The 2C acetate combines with coenzyme A to form acetylcoenzyme A
Overall equation for the link reaction
Pyruvate + NAD + CoA -> CO2 + reduced NAD + acetyl CoA
How many times will the link reaction occur per glucose molecule?
Twice
What are enzymes?
Molecules that other enzymes require in order to function
What are the three coenzymes in photosynthesis and respiration?
NAD, FAD, NADP
What are the three main functions of the Krebs cycle?
Breaks down macromolecules (pyruvate) into smaller ones (CO2)
The hydrogen atoms are carried to the electron transfer chain and provide energy to make ATP
Regenerates the 4C compound that combines with acetylcoenzyme A