The Link Reaction Flashcards
What happens for every glucose respired? - hint: think pyruvate
- 2 pyruvate made
- each one feeds in to the link reaction
What was the end product of glycolysis?
- pyruvate was made
What is pyruvate?
- Pyruvate contains a substantial amount of chemical energy that can be further utilised in respiration to produce more ATP
What will pyruvate do if oxygen is available?
- When oxygen is available, pyruvate will enter the mitochondrial matrix and aerobic respiration will continue
How does pyruvate move across the double membrane? What does it require to do this?
- Pyruvate moves across the double membrane of the mitochondria via active transport
- It requires a transport protein and a small amount of ATP
What is decarboxylation?
- removal of carbon dioxide
What is dehydrogenation?
- removal of a hydrogen atom
What are the steps of the link reaction?
- Pyruvate is oxidised by enzymes to produce acetate, CH3CO(O)- and carbon dioxide, requiring the reduction of NAD to NADH
- Combination with coenzyme A to form acetyl coenzyme A (acetyl CoA)
what are the products of the link reaction?
- acetyl coA (x2)
-carbon dioxide
-reduced NAD (x2)
what is co-enzyme A?
-A coenzyme is a molecule that helps an enzyme carry out its function but is not used in the reaction itself
- Coenzyme A consists of a nucleoside (ribose and adenine) and a vitamin
what is the role of co-enzyme A in the link reaction?
-In the link reaction, CoA binds to the remainder of the pyruvate molecule (acetyl group 2C) to form acetyl CoA
what is the role of co-enzyme A in the kreb cycle?
- It then supplies the acetyl group to the Krebs cycle where it is used to continue aerobic respiration
- This is the stage that brings part of the carbohydrate (or lipid/amino acid) into the further stages of respiration and links the initial stage of respiration in the cytoplasm to the later stages in the mitochondria
