Respiration, 5.7 Flashcards
What does respiration release?
Energy - ATP. CO2. Water.
Why is ATP needed?
Drives metabolic reactions. Active transport. Synthesis of molecules. Cell division. Movement.
What is an anabolic reaction?
Builds large molecules
What is a catabolic reaction?
Breaks down large molecules
What does ATP stand for?
Adenosine Tri-Phosphate
When is energy released from ATP?
When its hydrolysed - broken down into ADP + Pi
Does glycolysis need oxygen?
No
Where does glycolysis take place?
The cytoplasm
Is glycolysis aerobic or anaerobic?
Anaerobic
Describe the stages of glycolysis. Draw a diagram.
- Glucose is phosphorylated twice to make hexose bisphosphate (6C) - more reactive than glucose
- Broken down into 2 molecules of TP (3C)
- Hydrogen removed from TP and passed to NAD to form red. NAD
- Forms 2 molcules PA/pyruvate - also 4 molecules of ATP
What is the net gain of products from glycolysis?
2 ATP. 2 red. NAD. 2 Pyruvate.
What does NAD stand for?
Nicotinamide Adenine Dinucleotide
What is the role of NAD?
Enzymes that catalyse reduction and oxidation need a coenzyme (NAD) to accept hydrogens. Acts as a shuttle
What is the structure of NAD?
Nicotinamide. Adenine. 5C sugar. 2 Phosphate groups.
Where does pyruvate have to be transported to for the Link Reaction?
The mitochondrial matrix
Describe the stages of the Link Reaction. Draw a diagram.
- Pyruvate (3C) is decarboxylated and a molecule of CO2 (1C) is released.
- Pyruvate (3C) is also dehydrogenated, NAD accepts the hydrogen to form red. NAD
- Produces an acetyl group (2C)
- Coenzyme A (CoA) combines with the acetyl group to form acetyl CoA
Is the link reaction aerobic or anaerobic?
Aerobic - needs oxygen
What are the products of the Link Reaction?
2 red. NAD. 2CO2. 2 acetyl CoA.
Where does the Krebs Cycle take place?
Mitochondrial matrix
Is the Krebs Cycle aerobic or anaerobic?
Aerobic - requires oxygen
- Describe the stages of the Krebs Cycle. Draw a diagram
- Acetyl combines with oxaloacetate (4C) to form citrate (6C)
- Citrate is decarboxylated and dehydrogenated to producte 5C compound, CO2 and red. NAD
- 5C compound is decarboxylated and dehydrogenated to produce a 4C compound
- 4C compound temporarily combines with CoA, releases ATP from substrate level phosphorylation
- 4C compound is dehydrogenated to form red. FAD
- Atoms are rearrange - by isomerase - to form oxaloate
What are the products of the Krebs Cycle per molecule of glucose?
6red. NAD. 2red FAD. 4CO2. 2ATP.
What other substrates can be respired?
Fatty Acids. Glycerol. Amino acids.
How does the electron chain gain electrons?
From red. NAD and red. FAD. Release hydrogen atoms. The hydrogen splits into protons and electrons.