Respiration And Gas Exchange Flashcards
What is respiration?
A chemical reaction carried out in all living organisms
What happens during respiration?
Energy is released from glucose either in presence of oxygen (aerobic respiration) or the absence of oxygen (anaerobic respiration)
What does respiration result in?
The production of carbon dioxide and water as waste products
What form is energy transferred as during respiration?
ATP (adenosine triphosphate)
Where is ATP produced?
It is produced in respiration in the mitochondria
What is ATP required for?
It is required for living processes to occur within cells and organisms as it provides energy
What are the characteristics for aerobic respiration?
Requires oxygen, break down glucose completely, produced carbon dioxide and water, releases lots of energy
What are the characteristics of anaerobic respiration?
Doesn’t require energy, incomplete glucose breakdown, produces lactic acid in animal cells and carbon dioxide and ethanol in yeast, releases a little bit of energy
What is aerobic respiration?
The chemical reaction in cells that uses oxygen to break down nutrient molecules to release energy
What does aerobic respiration do?
Completely break down glucose to release a relatively large amount of energy for use in cell processes and reactions
What is produced in aerobic respiration?
Carbon dioxide and water as water products as well as releasing useful cellular energy
What is the word equation for aerobic respiration?
Glucose + oxygen —-> carbon dioxide + water
What is the symbol equation for aerobic respiration?
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
What is anaerobic respiration?
The chemical reaction in cells that breaks down nutrient molecules to release energy without using oxygen
What happens during anaerobic respiration?
An incomplete breakdown of glucose and so it releases a relatively small amount of energy for use in cell processes
What is the product of anaerobic respiration?
Different breakdown products are formed depending on the type of organism that the anaerobic respiration is taking place in
When does anaerobic respiration usually take place in animals and why?
During vigorous Excersise because when we Excersise at high intensities, the demand for oxygen exceeds the supply and the muscles still have a high demand for energy
Explain the process of anaerobic respiration in animals
When oxygen runs out, glucose is broken down without it, producing lactic acid instead. Glucose has not been fully broken down meaning there is still energy stored within the bonds of lactic acid molecules
Which form of respiration releases more energy?
Aerobic
What is the word equation for anaerobic respiration in animals?
Glucose —-> lactic acid
What is the symbol equation for anaerobic respiration in animals?
C6H12O6 —> 2 C3H6O3
What happens in anaerobic respiration in plants and fungi?
Glucose is incompletely broken down in the absence of oxygen to produce ethanol and carbon dioxide
What are the lungs?
The gas exchange surface in humans
What features do all gas exchange surfaces have to allow the maximum amount of gases to be exchanged across the surface in the smallest amount of time ?
Large surface area, thin walls, good ventilation with air, good blood supply
Why do gas exchange surfaces have a large surface area?
To allow faster diffusion of gases across the surface
Why do gas exchange surfaces have thin walls?
To ensure diffusion distances remain short
Why do gas exchange surfaces have good ventilation with air?
So that diffusion gradients can be maintained
Why do gas exchange surfaces have good blood supply?
To maintain a high concentration gradient so that diffusion occurs faster
Ribs
Bone structure that protects internal organs such as the lungs
Intercostal muscles
Muscles between the ribs which control their movement causing inhalation and exhalation
Diaphragm
Sheet of connective tissue and muscle at the bottom of the thorax to allow inhalation and exhalation
Trachea
Windpipe that connects the mouth and nose to the lungs
Bronchi
Large tubes branching off the trachea with one bronchus for each lung
Bronchioles
Bronchi split to form smaller tubes in the lungs connected to the alveoli
Alveoli
Tiny air sacs where gas exchange take place
Pleural membranes
The airtight membranes covering the lungs and the chest wall
What do muscles do on bones?
Pull on them, NOT push on them
How many sets of intercostal muscles are there?
2- they work antagonistically to facilitate breathing
What do the external intercostal muscles do?
Pull the rib cage up
What do the internal intercostal muscles do?
Pull the rib cage down
What does the diaphragm separate?
The thorax from the abdomen
What does the diaphragm do during inhalation?
contracts and flattens
What do the external set of intercostal muscles do during inhalation?
Contract to pull the ribs up and out
What does the contraction of intercostal muscles during inhalation do?
Increases the volume of the chest cavity (thorax)
What does the increase in the volume of the chest cavity during inhalation lead to?
Decrease in air pressure inside the lungs relative to outside the body
What happens to air during inhalation?
Air is drawn in
What happens to the diaphragm during exhalation?
It relaxes as it moves upwards back into its domed shape
What happens to the external set of intercostal muscles during exhalation?
They relax so the ribs drop down and in
What does the relaxation on the external set of intercostal muscles do?
Decreases the volume of the chest cavity (thorax)
What does the decrease in volume of the chest cavity lead to?
An increase in air pressure inside the lungs relative to outside the body
What happens to air during exhalation
Air is forced out
What do the internal and external intercostal muscles do during forced exhalation
They work as antagonistic pairs
What does working antagonistically mean?
They work in different directions to each other
When do we need to increase the rate of gas exchange?
During strenuous activity
What do the intercostal muscles do during forced exhalation?
They will work by pulling the ribs down and in to decrease the volume of the thorax more, forcing air out more forcefully and quickly
What is there a greater need to get rid of in the body during strenuous exercise?
Increased levels of carbon dioxide produced
Why does carbon dioxide need to get ridden of during strenuous activity?
This allows a greater volume of gases to be exchanged
What is the alveoli specialised or?
Gas exchange
Why does the alveoli have a large surface area to volume ratio?
Because there are many rounded alveolar sacs
Why do the alveoli and the capillaries around them have thin single layers of cells
To minimise diffusion distance
What levels of oxygen and carbon dioxide does ventilation maintain in the alveolar air space?
High levels of oxygen, low levels of carbon dioxide
Why does the alveoli have good blood supply?
Ensures constant supply of blood high in carbon dioxide and low in oxygen
Why is there a layer of moisture on the surface of the alveoli?
To help with diffusion as gases dissolve
What does smoking cause?
Chronic obstructive lung disease (COPD), coronary heart disease, increased risks of several types of cancer, including lung cancer
What chemicals are in cigarettes?
Tar, nicotine, carbon monoxide
What does Excersise do to the frequency of breathing and why?
Increase it in order to provide more oxygen for respiration and to pay off any subsequent oxygen debt
