Respiration Flashcards
Name the 3-carbon molecule that is an intermediate compound in both aerobic and anaerobic respiration?
Pyruvic Acid
What name is given to the biochemical pathway by which this intermediate compound is produced?
Glycolysis
What is produced from the intermediate compound in the muscle?
Lactic acid
What is produced from the intermediate compound when oxygen is not available in yeast
Ethanol
What compound has 6 carbon atoms?
Glucose
What compound has 3 carbon atoms?
Pyruvic Acid
What compound has 2 carbon atoms?
Acetyl coA
Give two functions of water in yeast cells
Solvent and for transport
Suggest an advantage of using ATP as an energy store in cells
High-energy molecule
Name two processes requiring ATP that occur in cells
Photosynthesis, Respiration
Name two substances, other than carbon dioxide, into which pyruvate may be broken under anaerobic conditions in cells
Lactic Acid, Ethanol
What is the name of the two-carbon compound into which pyruvate may be broken down under aerobic conditions
Acetyl Coenzyme A
Describe the fate under aerobic conditions, of Acetyl Co-enzyme A
Enters Krebs Cycle
Make three points concerning Metabolism
- Sum of all the chemical reactions in the body
- Controlled by enzymes
- Anabolic (Adding of small molecules to from large molecules) and Catabolic (Breaking down of large molecules into smaller molecules) are types
Make three points concerning the Krebs cycle
- Second stage of respiration
- occurs when oxygen is present
- ATP is produced
Make three points concerning ADP
- Adenosine DiPhosphate
- Low energy molecule
- ATP formed from ADP + P
Explain the term fermentation
Anaerobic Respiration
Name an organism that is used in industrial fermentation
Yeast
Name a compound which is used as a carbon source in yeast fermentation
Glucose
Give two differences, other than location, between stage one and stage two
Stage one is anaerobic, Stage two is aerobic
Stage one produces small amount of ATP, Stage two produces large amount of ATP
Where in the cell does stage one occur?
Cytosol
Where in the cell does stage two occur?
Matrix of Mitochondria
What term is used to describe respiration in which only stage one occurs?
Anaerobic
Name a chemical end product of Anaerobic Respiration
Ethanol
In what molecule, is the energy stored in the cell in stage two when electrons pass along an electron transport chain?
ATP
To what are the electrons transferred at the end of the electron transport chain?
Oxygen and H+
Name the substance formed by the loss of a phosphate group from ATP
ADP
What keeps the ATP cycle going?
Energy
Suggest a role for NAD/NADP+ in cell activities
Transfering electrons
If conditions are aerobic, pyruvate next passes to an organelle in which the second stage of the reaction takes place, what is this organelle?
Mitochondrion
Pyruvate is broken down to CO2 and a two-carbon compound. Name this two-carbon compound
Acetyl Co-EnzymeA
Acetyl group passes directly into a series of reactions in the second stage of respiration. Name this series of reactions and give one product, other than electrons, of these reactions
Krebs Cycle
Products : ATP, CO2, H+
In the electron transport chain, to what use is the energy put?
To form ATP
At the end of the electron transport chain, what happens to the electrons?
Transfered to Oxygen and H+
Write a balanced equation to represent aerobic respiration
C6H12O6 + 6O2 = 6CO2 + 6H20 + Energy
What is the cytosol?
Cytoplasm without organelles
Suggest a situation in which some cells in the human body may not be able to engage in the second stage of aerobic respiration
- Lack of Oxygen
- Exercise
- Restricted blood supply
What does ATP stand for?
Adenosine Triphosphate
What is the role of ATP in cells?
Stores energy in cells
To what substance is glucose normally converted in the first stage of respiration?
Pyruvate
In aerobic respiraton, the product of the first stage moves to the mitochondrion. Outline subsequent events in the total breakdown of this product
- Acetyl Coenzyme A enters series of reactions known as the Krebs Cycle
- Requires Oxygen
- Combines with 4C compound to form a 6C
- When 6C formed, Coenzyme A is recycled
- Regenerate 4C compound, removal of 2CO2 and 4 hydrogen pairs
- ATP produced
- NAD+ collects the H pairs and 4NADH are formed
- NADH enters electron transport chain and at the end of each system, the low energy molecule is removed by combining oxygen and hydrogen to from water
Under aerobic conditions, the pyruvate is converted to an acetyl group and in the process a small molecule is released. Name this small molecule
Carbon Dioxide
Distinguish between aerobic and anaerobic respiration
Aerobic - Requires Oxygen
Anaerobic - Does not require Oxygen
During glycolysis, a small amount of energy is released. Explain the role of ADP in relation to this released energy
Combines with phosphate and forms ATP
When Lactic Acid builds up in the blood, a person is said to be in oxygen debt. This debt must eventually be paid. Suggest how the debt is paid?
Increase breathing (Deeper or faster)
Distinguish between internal and external respiration
External Resp -process of gas exchange with environment or breathing
Interal Resp - Relase of energy from food using enzymes
Why is respiration essential to living things?
Provides energy for all reactions in a cell such as movement of muscles, growth of new cells
What is respiration?
Controlled release of energy from food
What controls respiration?
Enzymes
What happens to any energy not uses to make ATP?
Lost as heat
How is respiration a relatively efficient method of obtaining energy?
About 40% of the energy in glucose is converted to ATP during aerobic respiration
What is the product of Glycolysis?
Pyruvate
What is pyruvic acid?
organic acid which occurs as an intermediate in many metabolic processes, especially glycolysis.
Describe stage one of respiration
- Glucose, a six carbon sugar is converted to two 3 carbon sugars - pyruvic acid
- No oxygen is required, some of the energy released forms ATP molecules but most of the energy is used to form NADH
What is most of the energy released used to form in first stage
Some of it is - ATP
Most of it is used to form - NADH
Why does stage two occur in the matrix of the mitochondria?
Necessary enzymes are found here
How is the Acetyl group formed from the Pyruvic acid?
Removal of CO2 molecule
Describe how the acetyl co enzyme A is formed
- If O2 is present, the pyruvic acid enters mitochondrion
- Loses CO2 molecule to form a 2-Carbon molecule - Acetyl group
- Co-enzyme A links to acetyl group and forms acteyl co enzme A
Describe how NADH is formed
Pyruvic acid loses 2 high energy electrons that combine with NAD+ and a proton to form NADH
What is the fate of NADH
Electron Transport System
In what stage is NADH formed?
Stage two
Distinguish between the location of the Krebs Cycle and the Electron Transport Chain
Krebs Cycle - Matrix of Mitochondrion
Electron Transport Chain - Cristae of Mitochondrion
Describe the Electron Transport Chain
- NADH enters
- Christae of mitochondrion
- Oxygen is necessary
- High energy electrons are passed from NADH to the molecules
- As electrons pass from molecule to molecule they lose some energy which is used to form ATP
- End, low energy electron is removed by combining with Oxygen and hydrogen to form water
What is the name given to the production of ATP by electron transport chain?
Oxidative Phosphorylation
What is the main significance of electron transport system?
It produces energy rich ATP
Why is oxygen essential in electron transport chain?
It accepts the low energy electron at the end of the chain
If oxygen is absent, why would aerboic organisms die?
There is no oxygen to accept low energy electron and no ATP is formed - no energy for all cell reactions
-investigation to prepare and show the production of ethanol using yeast -
Why did you sterilise all the glassware before the experiment?
To prevent contamination of micro-organisms
-investigation to prepare and show the production of ethanol using yeast -
Name the substrate used in this experiment
Glucose
-investigation to prepare and show the production of ethanol using yeast -
What product, other than ethanol, was formed during fermentation
Carbon dioxide
-investigation to prepare and show the production of ethanol using yeast -
How did you know when the fermentation process was finished?
Bubbles stop forming
-investigation to prepare and show the production of ethanol using yeast -
How did you test for the presence of ethanol? Describe the result of this test if ethanol is present
Test - potassium dichromate and sulfuric acid
Result - turns green if alcohol present
-investigation to prepare and show the production of ethanol using yeast -
Why is the solution in the conical flask boiled?
To eliminate gases from solution - form anaerobic conditions
-investigation to prepare and show the production of ethanol using yeast -
Why is the liquid in the flask covered with oil?
To prevent oxygen from re entering the solution
-investigation to prepare and show the production of ethanol using yeast -
What’s the control of this experiment?
Don’t add yeast cells
-investigation to prepare and show the production of ethanol using yeast -
Describe how you prepared the alcohol
Prepare glucose solution - glucose dissolved in water
Boil solution in conical flask for 5 mins - eliminates gases to create anaerobic conditions
When cooled, add dried yeast
Cover liquid in flask with oil [prevent oxygen re entering solution]
Set up apparatus
Co2 is produced which turn limewater from clear to milky
Control - do same without adding yeast cells
-investigation to prepare and show the production of ethanol using yeast -
How do you show alcohol is produced?
Filter solution [remove yeast cells]
Add potassium dichromate solution into a test tube [note orange colour]
Add filtered solution into test tube
Add concentrated sulfuric acid to test tube
Warm test tube gently in beaker of hot water and turns from orange to green
What are the products of glycolysis and how are they formed?
ATP (ADP + P)
NADH (NAD+ + H+)
How many atps formed from glycolysis
Net gain of 2 ATP’S
When the pyruvic acid is broken down to AcetylCoA, what is released?
CO2
pair of hydrogen atoms which combine with NAD+ to form NADH
What is the purpose of the Krebs cycle?
To make as many NADH molecules as possible
How was NADH formed in the krebs cycle?
Removal of hydrogen atoms
-investigation to prepare and show the production of ethanol using yeast -
Why were the solutions to test for alcohol added after a certain period of time
to test for the presence of alcohol in the product
How do you know fermentation has ceased and why does fermentation eventually cease?
No more bubbles given off
Alcohol kills the yeast/ all sugar is used up and reaction can no longer occur.
Name a substance produced during aerobic respiration which is not a product of fermentation
Water
