B9 - Respiration (Y11 - Autumn 1) Flashcards
🟠 What Is Respiration?
Respiration is needed in every cell, and therefore takes place in every cell, and the chemical reaction takes place in the mitochondria.
🟠 What Is Aerobic Respiration?
Aerobic respiration is a chemical reaction that takes place in all living cells, in which glucose reacts with oxygen to produce carbon dioxide and water and stored chemical energy is released. Aerobic Resporation is an exothermic reaction.
🟠 What is the Aerobic Respiration Equation
Aerobic respiration can be summerised with the equation:
Glucose + Oxygen –> Carbon Dioxide + Water (energy transferred to the environment)
C6H12O6 + 6O2 –> 6CO2 + 6H2O (energy transferred to the environment)
🟠 How To Test For Carbon Dioxide (2 Ways)
Test 1 - Limewater Test:
- Take a test tube of limewater (a clear liquid).
- Blow gently through a straw into the limewater.
- After a short time the limewater turns cloudy, showing that carbon dioxide is present.
Limewater turns cloudy when carbon dioxide passes through.
Test 2 - Breathing Mirror Test:
- Get out a cold mirror (you could put one in the fridge).
- Breathe gently onto the mirror.
- If condensation happens on the mirror, them carbon dioxide is present.
🟠 What Does The Mitochondria Do In Respiration?
Aerobic respiration involves lots of chemical reaction. Each reaction is controlled by a different enzyme. Most of these reactions take place in the mitochondria of your cells.
Mitichondria are tiny rod-shaped parts (organelles) rgar are found in almost all plant and animal cells as well as in fungal and algal cells. They have a folded inner membrane that provides a large surface area for the enzymes involved in aerobic respiration. Thid number of mitochondria in a cell shows how active the cell is.
🟠 Why Do Things Need To Respirate?
The energy transferred during respiration supplies all the energy needs fir living processes in the cells:
- Living cells need eneegy ro carry out the basic functions of life. They build up large molecules from smaller ones to mske new cell material. Much of the energy transferred in respiration us used for these ‘building’ activities (synthesis reactions). Emergy is also trabsferred to break down larger molecules knto smaller ones, both during digestion and within the cells themselves.
- In animals, energy from respiration is transferred to make muscles contract. Muscles are working all the time in your body. Even when you sleep, your heart beats, you breathe, and your stomach churns. All muscular activities require energy.
- Mammals and birds maintain a constant internal body temperature almost regardless of the temperature of their surroundings. On cold days energy transferred from respiration helps you to stay warm, while on hot days you sweat and transfer energy to your surroundings to keep your body cool.
- In plants, energy from respiration is transferred to move mineral ions such as nitrates from the soil into root hair cells. It is also transferred to covert sugars, nitrates, and othee nutriengs into amino acids, which are then built up proteins
🟠 How do the following Organelles help with Resipration:
- Cytoplasm
- Nucleus
- Mitochondrion
- Cell Membrane
Cytoplasm:
Where enzymes are made. Location of reactions in anaerobic respiration.
Nucleus:
Holds genetic code for enzymes involved in respiration.
Mitochondrion:
Contain the enzymes for aerobic respiration.
Cell Membrane:
Allows gases and water to pass freely into and out of the cell. Controls the passage of other molecules.
❌ What Do Muscles Do When Exercising
Muscle tissue is made up of protein fibres that contract when energy is transferred from respiration. Muscle fibres need a lot of energy to contract. They contain many mitochondria to carry out aerobic respiration and transfer the energy needed. Muscle fibres usually occur in big blocks or groups, which contract to cause movement. They then relax, which allows other muscles to work.
Your muscles also store glucose as the carbohydrate glycogen. Glycogen can be converyed rapidly back to glucose to use during exercise. The glucose is used in aerobic respiration to transfer the energy needed to make your muscles contract.
❌ What 3 Things Happen When You Exercise
During exercise when muscular activity increases, several changes take place in your body:
- Your heart rate increases and the arteries supplying blood to your muscles dilate (widen). These changes increase the flow of oxygenated blood to your exercising muscles. This in turn increases the rate of supply of oxygen and glucose for the increased cellular respiration rate needed. It also increases the rate that carbon dioxide is removed from the muscles.
- Your breathing rate increases and you breath more deeply. This means you breathe more often and also bring more air into your lungs each time you breathe in. The rate at which oxygen is brought into your body and picked up by your red blood cells is increased, and this oxygen is carried to your exercising muscles. It also means that carbon dioxide can be removed more quickly from the blood in the lungs and breathed out.
- Glycogen stored in the muscles is converted back to glucose, to supply the cells with the fuel they need for increased cellular respiration. In this way, the heart rate and breathing rate increase during exercise to supply the mucles with what they need and remove the extra waste produced. Cellular respiration increases to supply the muscle cells with the increased levels of energy needed for contraction during exercise. The increase in your breathing and heart rate is to keep up with the demands of the cells.
🟠 What Is Anaerobic Respiration?
During hard exercise, anaerobic respiration takes place as well as aerobic respiration. Anaerobic resspiration does not need oxygen for it to happen, while it is also far more inefficient than aerobic respiration, because the glucose molecules are not broken down completely. In animal cells the end product of anaerobic respiration is lactic acid (which cauases pain and tiredness in the muscles) instead of carbon dioxide and water. Because the breakdown of glucose is incomplete, far less energy is transferred than during aerobic respiration.
🟠 What is the Anaerobic Respiration Equation
Glucose —> Lactic Acid
🟠 What Is Oxygen Debt
After anaerobic activity, oxygen is needed to neutralize the lactic acid. This is called oxygen debt. It is repaid after exercise. When exercise is over, lactic acid has to ge converted back to glucose in the liver. The glucose produced may then be broken down to produce carbon dioxide and water. This process neeeds oxygen.
Rapid and deep breathing is needed for a short period after high intensity exercise in order to repay the debt. Thus also helps to remove the carbon dioxide which accumulates in the blood during intense exercise.
🟠 What Happens When Your Muscles Fatigue
Using your muscle fibres vigorously for a long time can make them become fatigued and they stop contracting efficiently. One cause of this muscle fatigue is the build-up of lactic acid, peoduced by anaerobic respiration in the muscle cells. The build-up of lactic acid in the muscles as a result of anaerobic respiration creates an oxygen debt.
For example, repeated movements can soon lead to anaerobic respiration in your muscles - particularly if your not used to the exercise. If you are fit your heart and lungs will be able to keep a good supply of oxygen going to your muscles while you exercise for a relatively long time. If you are unfit, your muscles will run ahort of oxygen much sooner.
🟠 How Does Anaerobic Respiration Work In Other Organisms
Humans and other animals are not the only living organisms that can respire anaerobically. Plants and microorganisms can also respire without oxygen. However, when plant cells respire anaerobically, they do not form lactic acid, they form ethanol and carbon dioxide. Some microrganisms form lactic acid during anaerobic respiration - the bacteria used to form yoghurts, for example. Other microorganisms, including yeast is known as fermentation. People have made use of this for thousands of years. It is a very economically important reaction because it is used globally in the maufacture of bread and alcoholic drinks.
❌ Breathing During Exercise Describe And Explain:
Amount of breaths a Man takes Before and After exercise:
Resting:
15 breaths in 30 seconds
= 30 breaths/minute
Exercising:
21 breaths in 30 seconds
= 42 breaths per minute
(40% increase and an extra 12 breaths)
During exercise, the man’s breathing rate increased from 30 breaths per minute to 42 breaths per minute (an increase of 40%, and extra 12 breaths). This is due to the fact that a higher rate of breathing allows a larger volume of oxygen to be inhaled in a certain amount of time. Higher levels of oxygen intake allows more oxygen to be transported to the muscle cells in his body; allowing more aerobic respiration to take place in a more efficient manner. This results in more energy being released for his muscle to contract.
