First Five Silently in your notebook answer the

First Five Silently in your notebook answer the following question: Describe how oxygen passes from the blood into the respiring cells. Provide the definition for state and define.

Cellular Respiration The chemical reactions that break down nutrient molecules in living cells to release energy.

Describe Cellular Respiration The breakdown of glucose molecules to release energy in a form called ATP Takes place in the mitochondria Takes place in all living things Is a step by step process

Uses of Energy in the body muscle contraction protein synthesis cell division active transport Growth the passage of nerve impulses the maintenance of a constant body temperature.

Cellular Respiration There are two types of Cellular Respiration Aerobic Respiration Uses oxygen Releases a large amount of energy Anaerobic Respiration Does not use oxygen Releases a small amount of energy

Equations for Aerobic Respiration Word Equation glucose + oxygen Symbol Equation C 6 H 12 O 6 + 6 O 2 carbon dioxide + water 6 CO 2 + 6 H 2 O + energy

Why Use Aerobic Respiration? Glucose is good for energy storage but is not a usable form for cells. Releases a large amount of energy in a usable form ATP: Adenosine triphosphate Oxygen is usually available

Equations for Anaerobic Respiration in Yeast glucose alcohol + carbon dioxide + ATP C 6 H 12 O 6 → 2 C 2 H 5 OH + 2 CO 2 Uses: bread-making, brewing Anaerobic Respiration in Animals Glucose lactic acid + ATP Uses: Energy in exercise when oxygen used up

Why Use Anaerobic Respiration When oxygen is not available, but cells need energy Some cells live in low-oxygen environment Products are useful in society.

Exercise Creates an Oxygen Debt All cells require oxygen for respiration, which is supplied by the lungs aerobic respiration of lactic acid occurs in the liver When you run a race your muscles are using a lot of energy after exercise, a fast heart rate will transport lactic acid in blood from muscles to the liver after exercise, deep breathing will supply oxygen The cells in your muscles combine oxygen and glucose as fast as possible to release energy Oxygen is needed, therefore you breathe deeper and faster, your heart beats Since the oxygen debt used energy faster- though there is a limit without using oxygen, the lactic acid Which forces the body to start anaerobic respiration and therefore an oxygen debt needs to combine with oxygen until it is all gone and then your breathing and heart rate return to normal

Gas Exchange

Structures of the Gas Exchange System Structure Function Trachea Tube with incomplete rings of cartilage carries air to lungs; lined with cells making mucus, and cells with cilia to move the mucus away. Bronchi Carries air to lungs. Connect trachea to bronchioles. Bronchioles Carry air to lungs. Between bronchi and alveoli. Alveoli Tiny air sacs adapted for gas exchange Diaphragm Sheet of muscle with a fibrous middle part which is domed; it helps make breathing movements and separates the thorax from the abdomen Ribs Bones that protect and ventilate the lungs Intercostal muscles Move ribs for ventilation Pleural membranes Thin moist membranes forming an airtight seal around the lungs and separating inside of thorax from lungs

Pathway of air 1. Trachea 2. Bronchi 3. Bronchioles 4. Alveoli Like an upside down tree

The lungs contain 700, 000 tiny air sacs called alveoli. They are surrounded by a network of blood capillaries. Carbon dioxide diffuses from the blood into the air in the alveoli. Oxygen diffuses from the air in the lungs into the blood. The oxygenated blood then travels back to the heart to be pumped around the body.

Features of gas exchange surfaces in animals: Adaptations of the alveoli They have a large surface area for diffusion. Fluid to help dissolve gases and increase diffusion rate. A rich blood supply to maintain a steep diffusion gradient between the alveoli and the blood. Due to both the alveoli and the capillary only having walls one cell thick there is a short diffusion distance between the air and the blood which increases diffusion rate.

Protecting the Passageway* Ø Mucus: produced by goblet cells in the nose Ø Evaporates Ø Cilia: into air in nose and keeps it moist tiny hair-like projections that move back and forth; in nose, trachea, bronchi

Protecting the Passageway* Ø Particles like bacteria get trapped in the cilia and mucus Ø The cilia in the trachea and bronchi move the particles and mucus to the back of the throat so lungs don’t get blocked

Effects of Smoking* Tar Nicotine Highly addictive; heart disease Causes (lung) cancers Toxins of Tobacco Smoke Reduces blood’s ability to carry oxygen Carbon Monoxide Irritate lungs and can damage surface of alveoli Smoke Particles

Effects of Smoking cilia become less active, and goblet cells more active, when exposed to cigarette smoke, so that mucus collects in the lungs bacteria are likely to breed in the mucus, leading to bronchitis and other infections alveoli lose their elasticity, and coughing may damage their walls, leading to breathlessness and eventually to emphysema. cancer can be triggered by exposure to many of the chemicals in tar.

• Ventilation means moving air in and out of the lungs. • This requires a difference in air pressure and relies on the thorax (chest) being an airtight cavity. • Movements of the rib muscles and diaphragm change the volume inside the chest cavity and therefore the air pressure. • This causes the air to move in or out. • Along a PRESSURE gradient

Inspired vs. Expired Air Inspired Air (atmospheric air) • • Inspire: breathe in Oxygen 21% Expire: breathe out Carbon Dioxide 0. 04% Argon/noble gases 1% Water Variable Temperature variable Expired Air

Inspired vs. Expired Air • Why does the percent of argon stay constant? Oxygen Carbon Dioxide • How do these values relate to Argon/noble gases aerobic respiration? Water Temperature Inspired Air (atmospheric air) Expired Air 21% 16% 0. 04% 4% 1% 1% Variable Always high Always warm variable

* • What chemical test can we use to test for: • Carbon dioxide? Limewater • Oxygen? Inverted test tube to collect oxygen Inspired Air (atmospheric air) Expired Air Oxygen 21% 16% Carbon Dioxide Argon/noble gases Water 0. 04% 4% 1% 1% Variable Always high Always Temperature variable

Practice Questions* 1. Explain the meaning of the term gas exchange surface 2. List 3 features of gas exchange surfaces and explain how these are shown by the gas exchange surface in human lungs

Practice Questions* 1. Suggest why people who smoke cigarettes usually find it very difficult to give up. 1. Suggest why passive smoking can cause lung cancer.

Additional Links § Video- How Breathing Works § § Labeling practice § § http: //ed. ted. com/lessons/how-breathing-works-nirvairkaur http: //www. biotopics. co. uk/humans/resyst. html Readings: § http: //users. rcn. com/jkimball. ma. ultranet/Biology. Pages/P/ Pulmonary. html § http: //www. bbc. co. uk/bitesize/ks 3/science/organisms_be haviour_health/life_processes/revision/5/

http: //sepuplhs. org/high/sgi/teachers/photosynthesis 2_ sim. html http: //www. glencoe. com/sites/common_assets/science /virtual_labs/LS 12. html http: //www. wiley. com/college/boyer/0470003790/anim ations/photosynthesis. htm