Cellular Respiration Flashcards
What happens when glucose is broken down?
When glucose is broken down the chemical energy present in the glucose is released. 40% of the energy released per molecules is produced to ATP and the remaining 60% is lost as heat.
Where does glycolysis occur?
Glycolysis occurs in the cytoplasm, specifically the cytosol, of the cell. Each step is catalysed by a specific enzyme.
What happens in glycolysis?
One molecule of glucose is broken down into two molecules of pyruvate. A net release of energy consequently occurs (as the bonds of the glucose have been broken) and this is used to form two molecules of ATP.
The hydrogen atoms from the glucose molecules are also removed and carrier molecules such as NAD accept these high energy molecules (their electrons).
When acceptor molecules are carrying hydrogen, what are they called?
Loaded acceptor molecules.
How many intermediate steps and enzymes are used in glycolysis?
10 intermediate steps and enzymes are involved in glycolysis.
What is the net gain of glycolysis?
There is a net gain of 2 ATP molecules
What are the reactants and products of glycolysis?
Glucose- 2 pyruvate + 2ATP + 2 NADH
Where does the Krebs Cycle occur?
This process occurs in the mitochondria of cells- each mitochondrion has an outer membrane and a highly folded inner membrane however this process occurs in the matrix.
What happens to the pyruvate molecules in the Krebs cycle?
The pyruvate molecules produced during glycolysis contain a lot of energy in the bonds between the carbon atoms and in order to use that energy the cell must convert it into ATP- therefore pyruvate are processed during this cycle.
Prior to entering the cycle what happens to pyruvate molecules?
They are converted into acetyl coA and this is the link reaction. Once the link reaction occurs the Krebs cycle begins.
What are the products of the Krebs Cycle?
The products are 1 ATP, 3CO2, 3NADH and 1 FADH2 however due to 2 molecules of pyruvate being produced by glycolysis these figures must be doubled for each glucose molecule.
What is FAD?
FAD is similar to NAD in that it accepts hydrogens and high energy electrons to form FADH2.
Where does the electron transport chain occur and what is essential?
The electron transport chain occurs in the cristae of the mitochondria and oxygen is essential in this process.
What happens during the electron transport chain?
During this process electrons from loaded acceptors are brought to the inner membranes of the mitochondria- NADH and FADH2
The electrons are successfully transferred and are finally accepted by oxygen. When oxygen combines with a pair of electrons, it becomes negatively charged and then reacts with hydrogen ions to form water.
The NAD and FAD are re used to accept hydrogens and electrons.
How many ATP molecules are produced through the electron transport chain?
32-34 ATP are formed
