Gas exchange

• How do leaves adapt for gas exchange?


  - Large surface area for diffusion

  - Thin, so that there is a short diffusion pathway to the cells

  - Air spares to let gases diffuse into cells
• Gas exchange summary


  - Respiration is another name for him releasing energy

  - Respiration that uses oxygen is known as aerobic respiration

  - Aerobic respiration is the breakdown of glucose to energy in a form

  which every cell can use in the presence of oxygen

  - You receive significantly more (up to 19 times) through respiring aerobically as opposed to anaerobically

  - The equation is:

  C6H12O6+ 602 → 6C02 + 6H20 (+ Energy)

  - Aerobic respiration takes place in almost all living things

  - Organisms have to to get rid of the Carbon Dioxide and excess water; removal of CO, is called excretion (the removal of the toxic waste products of respiration), and maximum energy that is released from the glucose

  - The energy from respiration is used for heat to keep our bodies at 37 degrees C, for movement and to allow enzymes to work in our cells

  - Yeast/Fungi can respire anaerobically in a process called fermentation to produce ethanol

  - This is useful in beer and wine making processes
• Gas exchange in animals


  - In animal cells, anaerobic respiration produces lactic acid which can build up in our muscules, causing a painful condition knowns as cramps

  - The equation for anaerobic respiration in animals is:

  Glucose → Lactic acid + COz (+ Energy)
• What is a factor that can change the rate of photosynthesis?

  The rate of photosynthesis can change based on the time of day and how much sunlight there is
• Photosynthesis ____


  Only happens during day light hours. This will use up all of the CO2 from respiration and also take some more in from the air
• Respiration ___


  Is not the same as breathing, it is a chemical reaction inside your cells which release energy from glucose
• What is human gas exchange?


  - This is needed to get oxygen into our bodies for respiration

  - Air moves into our lungs, the oxygen then diffuses into our red blood cells

  - Red blood cells carry orygen to our cells
• What is in the human respiratory system?


  - Nose

  - Mouth

  - Epiglottis

  - Trachea

  - Picural membranes

  - Bronchi

  - Bronchiole

  - Diaphragm

  - Muscles between the ribs

  - Ribs

  - Lung

  - Heart

  - Air sacs (alveoli)
• What makes up the thorax?


  - Lung

  - Heart

  - Air sacs (alveoli)

  - Ribs

  - Muscles between the ribs
• Cilia cells (HG)


  Hairs in your nose
• Cartilage (HG)


  Keeps your trachrea from colapsing when you sleep
• Thorax


  This is the top half of your body
• Diaphragm


  A sheet of muscle separating the thorax from the abdomen
• Pleural membranes


  Surround the lungs
• Intercostal muscles


  These are in between the ribs, they help us breate in and out by moving

  the rib cage
• What happens when we breathe in?


  - Intercostal muscules contract

  - The ribs move up and out

  - The diaphragm contracts and flattens

  - The volume of the thorax increases

  - This decreases pressure in the lungs

  - Air moves into the lungs
• What happens when we breathe out?


  - The intercostal muscles and diaphragm relax

  - The ribs move down and in

  - The diaphragm moves up

  - The volume in the thorax decreses

  - Air is fored out
• % of nitrogen when we breathe in?

  78%
• % of oxygen when we breathe in?

  21%
• % of carbon dioxide when we breathe in?

  0.04%
• % of nitrogen when we breathe out?

  78%
• % of oxygen when we breathe out?

  17%
• % of carbon dioxide when we breathe out?

  4%
• Perstalsis


  Muscles that move food down your oesophagus and gut
• What are alveoli?


  - Millions of alvedi provide a large surface area for gas exchange

  - Alveoli are one cell thick so there is a

  short diffusion pathway

  - Blood is constantly moving, maintaining a concentrated gradient for oxygen diffusion

  - Capillaries are one cell thick to providing a short diffision pathway
• What are the long term effects of exercise?


  - The diaphrage and intercostal muscles become stronger

  - The chest cavity becomes longer so lung volume can increase more

  - Increased volume - more air taken in one breath

  - Increase in capillaries production in the lungs = oxygen diffuse into the blood
• What does the C in CORMS stand for?

  Control
• What does the O in CORMS stand for?

  Organisms
• What does the R in CORMS stand for?

  Repeats
• What does the M in CORMS stand for?

  Measure
• What does the S in CORMS stand for?

  Same
• What effect does smoking have on the human body?


  - It damages alveoli

  - It causes diseases such as a emphysema

  - The tar damages cilia in the trachea and lungs, this means the smoker gets more chest infections

  - Irritats bronchi leading to smoker's cough

  - Carbon monoxide binds to red blood cells so they don't carry oxygen , this also leads to high blood pressure and increases the chance of heart disease

  - Tobacco smoke contains chemicals called carcinogens, these cause cancer
• Active site


  Where the enzyme reacts with the substrate
• Denatured


  The enzyme dies
• Anerobic respiration


  - Releasing energy from glucose without oxygen

  - It releases much less energy than aerobic respiration
• Anaerobic respiration equation for plants and fungi


  Glucose --> ethanol + carbon dioxide (+energy)
• Anaerobic respiration equation for animals

  glucose --> lactic acid + energy
• What is lactic acid?


  - Lactic acid can build up in muscle causing cramps and create an oxygen debt

  - The 'oxygen debt' needs to be 're-payed '

  - This is why we breathe in deeply after exercise (pant) we take in oxygen

  - The lactic acid is broken down into CO2 and water
• Respiration


  - This is not the same as breathing

  - Respiration is a chemical reaction inside cells which releases energy from glucose

  - Aerobic respiration needs oxygen
• Respiration word equation


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