Respiration Flashcards
aerobic respiration is a two-stage process. Name the location where each stage occurs
- stage one- cytosol
2. stage two- mitochondria
Yeast cells produce ethanol in a process called fermentation is this process affected by temperature
yes, apparatus is placed in water bath at 25C which is the ideal temperature for yeast enzyme
Name a substance that yeast can use to make ethanol
Pyruvic acid
Name a substance produced during aerobic respiration that is not produced during fermentation
ethanol
Give an account of a chemical test to demonstrate that alcohol
- put a few drops of sodium dichromate into the test tube
- add some of the filtered product
- place the test tube in a beaker of hot water
- potassium dichromate turns from orange to green
Why does fermentation eventually cease?
when lactic acid builds up oxygen is depleted
Give one example of industrial fermentation, include the type of micro organism and the substance produced
bacteria and yeast used to produce products such as yogurt
Distinguish between anaerobic and aerobic respiration
- Anaerobic- release of energy without oxygen
2. Aerobic- release of energy using oxygen
Write a balanced equation to summarise aerobic respiration
C6H12O6+O2 —> 6CO2+6H2O
Suggest one reason why living things need to respire
for organisms to survive and reproduce
Define respiration
release of energy from food using enzymes
What is the first stage process of respiration called
Glycolysis
In the first stage of respiration there is a release of ATP as glucose is converted to another substance, name this substance
pyruvic acid
In respiration the acetyl group enters a cycle of reactions. What is the name given to this cycle?
Kreb’s cycle
To what is pyruvic acid converted under anaerobic conditions in
- Yeast
- Human muscle cell
- Alcohol
2. lactic acid
under aerobic conditions pyruvic acid is converted to an acetyl group and in the process a small molecule is released. name this small molecule
Carbon dioxide
If yeast cells are kept under anaerobic conditions alcohol and another substance are produced
What are anaerobic conditions?
no oxygen
Does the first stage of respiration require oxygen?
no its anaerobic
What name is given to the first stage of respiration?
glycolysis
Where in the cell does second stage take place
Mitochondria
Where in the cell does the first stage of respiration take place
cytosol
Comment on the amount of energy released in the second stage of respiration
it releases a lot of energy
Name a compound to which pyruvic acid may be converted in the absence of oxygen
lactic acid
two ways in which the energy released by respiration is used in the human body
- Cell division
2. nerve impulses
In stage 1 glucose is broken down. Where in the cell does this happen?
in the cytoplasm of the cell
What is cytosol?
liquid in the cell that surrounds the cell organelles
Does the first stage of respiration release a small or large amount of energy?
small amount of energy
Where does the second stage of respiration take place
mitochondria
Give 2 industrial uses of anaerobic respiration of yeast
- alcohol
2. yoghurt
Suggest a role for NAD/NADP+ in cell activities
NAD- trap and transfer energised electrons and hydrogen ions in cell activities
Pyruvate is broken down to CO2 and a two carbon compound. Name this two-carbon compound
Acetyl-CO-A
Name the series of reactions in the second stage of respiration
Kreb’s cycle
Respiration
release of energy using enzymes it can be aerobic or anaerobic
Describe the experiment “To produce alcohol using yeast””
set up the test flask as follows: yeast+glucose
1. pour 300cm of glucose solution in a conical flask
2. boil the glucose solution for 5 minutes (removes O2 and creates anaerobic conditions)
3. Add yeast to the glucose
4. cover the solution with oil (prevents O2 from entering)
6. Use glass tubing to connect the flask to a beaker containing limewater (limewater is a reagent to test for carbon dioxide)
7. Place flask in water bat @ 30C (optimum temp for yeast fermentation)
8. Monitor the apparatus until fermentation has stopped (no more bubbles)
9. Prepare a control flask with just glucose
10. Results Test: Limewater turns milky (CO2 is present)
Yeast ferments glucose releasing CO2 gas
Control: Limewater remains clear
There is no yeast present to ferment the glucose
Write a brief note on glycolysis
- First stage of respiration
- Anaerobic (no oxygen)
- Glucose is split to form pyruvate (3C)
- Low energy release
- Occurs is cytosol (liquid part of cytoplasm)
Write a brief note on Acetyl Co-enzyme A
- Formed from Pyruvic acid (3C)
- Enters the Krebs cycle
- Takes place in mitochondria
- Aerobic (oxygen is present)
Write a brief note on Electron transport system
- Aerobic
- Occurs in cristae of mitochondria
- Carries high energy electrons from NADH and Oxygen and it combines with protons (H+)
- Water is formed at the end of the chain
- High energy release
Write a brief note on Krebs cycle
- Occurs in the second stage of respiration
- Occurs in lumen of the mitochondria
- Starts with acetyl-co-enzyme-A
- Products:CO2, protons, energised electrons
Write a brief note on ADP
- Called adenosine di-phosphate
- Low energy molecule
- Accepts a phosphate and energy to form ATP
Name a biological advantage and disadvantage of fermentation
- Advantage: source of energy for ATP formation in oxygen deficient environment
- Disadvantage: produces only 2 ATP molecules, low energy yield
Name the advantages of using immobilised cells
- Cells can be recovered easily
- Cells can be re-used
- Gentle it doesn’t damage cells
Describe the test you carried out to see the presence of alcohol
- Iodoform test
- Add potassium iodide solution and sodium hypochlorite solution
- Transfer to a water bath for 5 minutes
- Result: if alcohol is present yellow crystals will form
Name 3 differences of Aerobic and Anaerobic respiration
- Aerobic: - involves stage 1 and 2
- uses oxygen and produces high energy
- products: CO2 and H2O - Anaerobic: - involves stage 1
- Does not use O2 and produces low energy
- Products: Ethanol and CO2 (Yeast) or Lactic acid (Human muscle cells)
Suggest an advantage to the cell of using ATP as an energy source instead of breaking down a sugar molecule every time energy is needed
- Energy is released easily
Name the nitrogenous base and the sugar present in ATP
- Nitrogenous base -> adenine
- Sugar -> Ribose
Give a balanced equation to summarise the process of aerobic respiration
- C6H12O6+6O2——-> 6CO2+6H20+energy
What happens to Pyruvate before Krebs cycle
-It looses a carbon and changes into acetyl
What are the products of the Krebs cycle
- ATP
- CO2
- NADH
Fate of products of the Krebs cycle
ATP–>Breaks down and releases energy
CO2–>Released into the atmosphere
NADH–> Moves to electron transport system, it breaks down and releases electrons
What is the final electron acceptor in aerobic respiration?
Oxygen
What does NAD stand for?
Nicotinamide Adenine Dinucleotide
Name 2 types of particle that are transferred by NAD
Electrons and Protons
Name 3 carbon molecule that is intermediate in both aerobic and anaerobic respiration
pyruvate
What name is given to the biochemical pathway by which this intermediate compound is produced?
Glycolysis
What is the fate of pyruvate
- It looses CO2 and is converted to Acetyl-Co-Enzyme-A
- Joins and enters Krebs cycle producing CO2, NADH,ATP
- NADH moves to electron transport system releasing 2 energised electrons which pass through electron acceptors, they loose their energy to form ATP
- At the end of electron transport system water is formed when low energy electrons combine with protons and oxygen
What is produced when oxygen is not present
- In muscle?
- In Yeast
- Lactic acid
2. Alcohol
