Respiration Flashcards
What is the definition of energy?
The capacity to do work
List four uses of the work of a cell
Active transport, secretion, endocytosis, replication of DNA
What is ATP, and what is it made up of?
Adenosine triphosphate. It is made up of Adenine, ribose sugar (collectively known as adenosine) and three phosphates.
What is respiration?
The breakdown of organic molecules so that energy is released to synthesis ATP.
What is hydrolysis?
The breakdown of large organic molecules by the addition of water.
Name 3 respiratory substrates.
Glucose, fatty acids and amino acids
What is phosphorylation?
The addition of a phosphate to a molecule.
How is energy released from ATP?
The terminal phosphate is removed from ATP converting it to ADP and an inorganic phosphate with energy released. Catalysed by ATPase
What are 3 advantages of ATP over glucose?
1) Energy is released in small steps
2) Hydrolysis of ATP is a single reaction releasing energy immediately
3) ATP is easily transported around the cell.
What are the four stages of respiration and give a brief description of each.
1) Glycolysis - Splitting of glucose into two 3 carbon pyruvate molecules.
2) Link reaction - Conversion of pyruvate into 2-carbon acetyl coenzyme a (Acetyl CoA)
3) Krebs cycle - Feeding of Acetyl CoA into a cycle of oxidation reduction
4) Electron Transport Chain (ETC) - aka Oxidative phosphorylation. Use of electrons and hydrogens to synthesise ATP.
Describe the process of glycolysis and draw it.
Occurs in the cytoplasm and does not require oxygen. Glucose activated by phosphorylation. Two ATP molecules are hydrolysed. Glucose to Fructose Bisphosphate. Fructose bisphosphate to two 3 carbon Triose phosphate. Oxidised by the loss of Hydrogen to two 3 carbon pyruvate molecules. The hydrogen is collected by NAD in a process called dehydrogenation. Net gain of 2 ATP as 2 ATP produced per molecule of pyruvate produced.
Describe the process of the link reaction and draw it.
Pyruvate is transported into the matrix of the mitochondrion. Pyruvate decarboxylated (removal of one molecule of CO2) and dehydrogenation (removal of H2 to convert NAD to NADH). Forms acetate which combines with CoA to form 2-carbon Acetyl CoA.
Describe the process of the Krebs cycle and draw it.
Matrix of the mitochondrion. 2-carbon Acetyl CoA combines with 4-carbon Oxaloacetate to produce 6-carbon Citrate. Then Decarboxylated to 5-carbon Oxoglutarate. Decarboxylated to form 4-carbon Oxaloacetate. At 3 points NAD to NADH, and 1 point FAD to FADH. One molecule of ATP produced in substrate level phosphorylation. This whole process occurs twice.
Describe the electron transport chain and draw it.
Inner mitochondrial membranes (Cristae). ATP produced through oxidative phosphorylation. Hydrogen and then its electrons are passed through a series of carriers at progressively lower energy levels in a series of redox reactions and at certain points enough energy is available to produce ATP. Oxygen is the final electron acceptor forming water catalysed by cytochrome oxidase.
How many ATP to NAD and FAD provide?
NAD - 3
FAD - 2
