4.1 Aerobic & Anaerobic Respiration Flashcards
What is cellular respiration?
An exothermic reaction which transfers energy from glucose, and is continuously occurring in living cells.
How do organisms use their energy? (3)
- Build larger molecules from smaller ones, e.g. combining amino acids to make a protein.
- Muscular contraction.
- Maintain body temperature.
What is metabolism?
All the chemical processes that occur within a living organism in order to maintain life.
What is aerobic respiration?
Aerobic respiration is what happens when there’s plenty of oxygen available. It breaks down glucose and combines the products with oxygen to make carbon dioxide and water. Aerobic respiration is the most efficient way to transfer energy from glucose. It produces lots of ATP - 32 molecules per molecule of glucose.
Why is the energy that is transferred by aerobic respiration used to make a substance called ATP?
The energy transferred by aerobic respiration can’t be used directly by cells.
What is ATP used for?
Essential processes, such as breaking and making molecules, active transport, and contracting muscles (animals only).
Cells can respire using glucose as a substrate, however what other organic molecules can organisms use as substrates for respiration?
Carbohydrates, proteins, lipids
What is the word equation for aerobic respiration?
glucose + oxygen —> carbon dioxide + water
Where does respiration take place in eukaryotic cells?
Mitochondria. The mitochondria contain most of the enzymes needed to control aerobic respiration reactions.
Where does respiration take place in prokaryotic cells?
Cytoplasm
How can you investigate how the rate of respiration in yeast is affected by different substrates? (5)
1) Put a set volume and concentration of substrate solution in a test tubes.
2) Put the test tube in a water bath set to 25 degrees.
3) Add a set mass of yeast to the test tube and stir for 2 minutes.
4) Attach the test tube to a gas syringe and measure the volume of carbon dioxide produces in a set amount of time.
5) If you divide the volume of carbon dioxide produced by the time taken to produce it, you can calculate the overall rate of respiration. You can then repeat the experiment with a different substrate and compare the two rates.
How many molecules of ATP are produced per glucose molecule in anaerobic respiration?
2
Where does anaerobic respiration take place?
In the cytoplasm of animal and plant cells (and some microorganisms).
What are the 3 reasons that mean anaerobic respiration will take place?
1) Human cells - When you do really vigorous exercise, your body can’t supply enough oxygen to your muscle cells for aerobic respiration - they have to start respiring anaerobically as well.
2) Plant root cells - If the soil a plant’s growing in becomes too waterlogged there’ll be no oxygen available for the roots to, so the root cells will have to respire anaerobically.
3) Bacterial cells - Bacteria can get under your skin through puncture wounds caused by things like nails. There’s very little oxygen under your skin, so only bacteria that can respire anaerobically can survive there.
Describe what anaerobic respiration produces in animals and some bacteria?
In animals and some bacteria, glucose is only partially broken down during anaerobic respiration and lactic acid is formed as a waste product. The word equation is: glucose —> lactic acid.
