Biology 4.4 Review Questions w/ 4 additional questions
Is glucose a reactant in the aerobic stages of cellular respiration? Explain.
No the first aerobic part of cellular respiration is the electron transport chain. Glucose is not present. Prior to the aerobic stages of cellular respiration, glucose has been broken down into 2 pyruvates in glycolysis, an anaerobic process that is a "pre- step" to cellular respiration..
What is an electron carrier?
FADH2
Describe in your own words the function of the Krebs cycle.
The main function of the Krebs cycle is to transfer high energy electrons to the electron transport chain using the carriers used in Krebs cycle.
Explain the functions of electrons, hydrogen ions, and oxygen in the electron transport chain.
Electrons in the ETC are used by proton pumps to move hydrogen ions across the membrane. Hydrogen ions diffuse down the ATP synthase, which causes it to work and produce ATP by adding a phosphate to ADP. Oxygen is used to pick up hydrogen ions and electrons to make water.
How are hydrogen ions involved in the electron transport chain?
Hydrogen ions are moved across the membrane. Then they diffuse down the ATP synthase. Hydrogen ions "power" the ATP synthase.
What is an electron acceptor?
NAD+
What is an electron carrier?
NADH
How are the products of the Krebs cycle important for making ATP?
NADH and FADH2 carry electrons to activate proton pumps that pump H+ inside the membrane so they can diffuse through the ATP synthase, which makes ATP.
Is oxygen necessary for the production of all ATP in your cells? Why or why not?
No it produces most of all ATP. When there is not oxygen available in your cells, you use fermentation.
Does glucose actually react with oxygen during cellular respiration? Explain.
No; glucose is broken down into 2 pyruvates so they can be used in cellular respiration. It is the pyruvate that is used to make NADH and FADH2 (through Krebs cycle) so that the Electron Transport Chain to be able to make ATP.
What is the role of pyruvate in cellular respiration?
Pyruvates are used to produce ATP in cellular respiration. They are what makes the Krebs cycle work.
How does the electron transport chain depend on the Krebs cycle?
The electron transport chain depends on the Krebs cycle to produce NADH and FADH2. These are the starting materials for the chain to be able to make ATP.
Does glycolysis directly produce as much ATP as the Krebs cycle? Indirectly? Explain your answer.
Yes; directly because the Krebs cycle makes 1 ATP molecule for every 1 pyruvate; since the end results of glycolysis are 2 pyruvates, the Kreb cycle goes through 2 cycles in order to make 2 ATP in total (1 ATP for each of the 2 pyruvates). Cells also gain 2 ATP at the end of one cycle of glycolysis. So the Krebs cycle makes 2 ATP in two cycles of Krebs and glycolysis makes 2 ATP in one cycle. So directly, they produce the same amount of ATP. But, INdirectly, Krebs makes more because it allows ETC to happen.
What cause proton pumps to work?
electrons
