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Flashcards in Respiration and Human Gas Exchange Deck (49)
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Define respiration

The chemical process that provides the body with energy needed for all other life processes


What is respiration used for?

- to drive chemical reactions needed to keep organisms alive
- movement
- cell division
- homeostasis
- active transport (loving molecules against concentration gradient)
- for the transmission of nerve impulses


Respiration is only ...% efficient?

40% (heat also released)


What are the two types of respiration?

Aerobic and anaerobic


Word equation for aerobic respiration

glucose + oxygen --> carbon dioxide + water + ATP


Aerobic respiration word equation:

C6H12O6 + 6O2 --> 6CO2 + 6H20 + ATP


What does aerobic respiration do?

Releases energy in cells breaking down food substances whilst in the presence of oxygen


Word equation for anaerobic respiration

glucose --> lactic acid +ATP


What happens with products from aerobic respiration?

Water: used in body
CO2: extorted through lungs and released into the air


Camel example

stores fat - broken down by respiration - product of respiration is water - perfect for dry conditions


Where do the reactants come from?

glucose: broken down foods
oxygen: air via lungs


ATP and respiration

1. Energy is released which is then used to make a spacial energy molecule called ATP
2. ATP is how energy is stored for later use by the body
3. Aerobic respiration happens all the time and in all cells usually in the mitochondria
4. Animals get the oxygen needed in the air through their ventilation systems
5. Plants get the oxygen needed in the air through the stomata
6. Plants produce their food by photosynthesis and then through respiration release energy from it.


Does oxygen for respiration in pants necessarily come from photosynthesis?

No - although it is a byproduct of respiration
Plants just take in any oxygen from the air
Respiration required day and night - even when no sunlight


Why can humans respire anaerobically but only for short amounts of time?

- Even though the process is relatively inefficient, it's better to continue respiring and be able to run away from danger – or run a race
- preferable to release less energy but remain alive


Plant cells and yeast anaerobic word equation:

glucose --> ethanol + carbon dioxide + energy released


Why is less ATP produced in anaerobic respiration?

glucose is only partially broken down, less energy is released from each glucose molecule


What does anaerobic respiration occur in?

- diving animals eg whales and seals
- inside parts of plants where diffusion of oxygen is too slow for aerobic respiration eg inside seeds or in root cells in waterlogged ground
- in muscle cells where vigorous exercise requires more energy than can be supplied from increased supply of oxygen from higher breathing and faster heart rate


What does EPOC stand for?

Excess Post - exercise Oxygen Consumption


What is EPOC?

The amount of oxygen our body consumes following exercise (even if aerobic) that is above and beyond the pre-exercise oxygen consumption baseline
Lactic acid builds (causing lack of oxygen) up until oxygen is available again - then converted back to glucose and stored or fully broken down using oxygen to CO2 and H2O.
Used to return processes in the boy back to their stable state and remove lactic acid


Practical to show respiration is taking place?

- Collect container with hydrogen - carbonate indicator
- Place maggots into container and seal
- Watch what happens to colour of the hydrogen carbonate indicator


Predict what will happen to the temperature of flask A and B over time

What is the purpose of flask B?

The temperature in A increases, B stays the same. The germinating seeds are respiring which releases heat.

B is a control experiment for comparison, the boiled seeds will not respire. (Do not write fair test!)


Why is indicator better than limewater?

Indicator is better than limewater because very sensitive to changes in pH so shows a clear, definitive change and also suggests levels of CO2 produced not only if present at all.


Key words of human gas exchange diagram?

- thorax
- ribs
- intercostal muscles
- diaphragm
- trachea
- bronchi
- bronchioles
- alveoli
- pleural membranes


Explain ventilation - inhaling

- air breathed into lungs
- diaphragm contracts and flattens in shape
- external intercostal muscles contract, making ribs move upwards and outwards
- changes cause volume of thorax to increase
- so air pressure to decrease
- and air to enter the lungs


Explain ventilation - exhaling

- air breathed out from lungs
- diaphragm relaxes and returns to its domed shape, pushed up by the liver and stomach (pushes up on lungs)
- external intercostal muscles relax, allowing ribs to drop back down (also presses on lungs)
- if breathing hard intercostal muscles also contract, helping the ribs to move down
- changes cause volume of the thorax to decrease
- causes the air pressure in the thorax to increase
- causes air to be forced out of the lungs


Air moving in to the lungs

- when breathe in, air enters through nose and mouth. In the nose the air is moistened and warmed
- air trails down trachea to the lungs
- tiny hair called cilia remove dirt and microorganisms
- air enters lungs through bronchi which branch and divide into bronchioles
- at the end of the bronchioles are air sacs called alveoli
- alveoli covered in tiny blood capillaries
- this is where gas exchange occurs


What is gas exchange in alveoli?

Where oxygen and carbon dioxide are exchanged between the blood and the air in the lungs.


Explain the role of the trachea, bronchi and bronchioles in breathing

trachea - carries air from mouth down to lungs
bronchi - the two large divisions of the trachea as it reaches the lung, supported with rings or cartilage
bronchioles - the fine tubes in the lungs that carry air to alveoli


Explain the role of the alveoli, pleural membranes

alveoli - diffusion of gases
pleural membranes - thin layers that reduce friction between the lungs and the inside of the chest wall during breathing


Explain the role of the ribs and intercostal muscles and the diaphragm

ribs and intercostal muscles - protect the lungs but also help expand the volume of the thorax during forced or deep breathing
diaphragm - muscular sheet below lungs which controls relaxed breathing