2.8 Cell respiration Flashcards
Glucose
-This is the preferred energy source for brain cells and is broken down in muscle cells for energy.
-Glucose is the most widely used source of energy in living organisms.
Define cellular respiration
The gradual and controlled release of energy by breaking down organic compounds to produce ATP ( A denosine T ri P hosphate).
What is the purpose of enzymes in cellular respiration?
They that control the process to ensure that energy is produced when it is required.
Diagram of overview of cellular respiration in a cell
What are the three main processes of cellular respiration?
-Glycolysis
-The Krebs cycle
-The electron transport chain
What do the three main processes of cellular respiration do?
They generate energy in the form of ATP.
What is ATP?
-A molecule that carries energy within the cell.
-It can be compared to a currency that is used to pay for different biochemical processes such as movement of substances, contraction of muscles and synthesis of large molecules.
Diagram showing the structure of ATP
Where does glycolysis take place?
In the cytoplasm
Where do the Krebs cycle and oxidative phosphorylation (and electron transport chain) take place?
In the mitochondria.
Within the mitochondria, where does the Krebs cycle occur?
In the matrix
Within the mitochondria, where is the electron transport chain located?
On the inner membrane of the mitochondrial envelope.
Function of ATP
-ATP fuels most of our body’s energy needs.
-ATP from cell respiration is immediately available as a source of energy in the cell.
-Without it we would not be able to move, think, digest food, conduct nerve signals or breathe.
-Energy is produced when ATP is hydrolysed.
-It should be noted that this same energy was generated during respiration and stored in the energy-rich phosphate bond of ATP.
Diagrm showing the hydrolysis of ATP to produce energy
Why do we breathe in oxygen?
To support aerobic respiration.
When oxygen (O 2 ) is present, aerobic respiration can yield ___
Far more ATP than under anaerobic conditions, as most of the energy contained in a glucose molecule can be harvested and converted into ATP.
What is the main reason for the increased ATP production in aerobic respiration?
-That during aerobic respiration, all the four steps of cellular respiration are completed (in anaerobic respiration only glycolysis is completed).
-The reason for this increased yield is that 6-carbon glucose is systematically and gradually broken down to 6 CO 2 molecules.
-Each step yields potential energy, which can be converted into ATP in the electron transport chain.
3 key facts about aerobic respiration
1) It requires oxygen
2) It gives a large yield of ATP from oxidation of glucose
3) It occurs in the cytoplasm and mitochondria
Equation to show aerobic cell respiration
Which method of respiration is more efficient?
-It is much more efficient to respire aerobically than anaerobically.
-That is why long distance runners try to maintain an aerobic speed.
-If they use up the available oxygen, their muscles will start anaerobic respiration, producing much less energy.
Diagram showing the comparison between anaerobic and aerobic respiration.
When describing cell respiration you should mention that ___
-It produces ATP molecules.
-You should avoid using descriptions such as ‘energy production’ as it is too vague and does not explain the main purpose of respiration.
What is the function of ATP molecules?
They provide energy for biochemical processes such as pumping molecules across membranes.
Where is the electron transport chain located in the diagram of a mitochondrion below?
-C
-C represents the inner mitochondrial membrane (folded into cristae) where the electron transport chain takes place.
Diagram showing the different uses of yeast
Diagram showing two anaeronic pathways compred to the aerobic pathway
Diagram showing how a respirometer can be used to measure the respiration rate of living organisms
Diagram showing different methods of measuring the respiration rate in living organisms
