Respiration

I. Cellular Respiration A.Biochemical process cells use to release energy from glucose B.Energy is stored in the bonds of adenosine triphosphate (ATP).

I. Cellular Respiration (cont) A.When a phosphate is removed it is changed to ADP + Phosphate and energy is released B.Water + ATP → ADP + P + Energy C.Two Types of cell respiration A.Aerobic – uses oxygen B.Anaerobic – without oxygen

I. Cellular Respiration (cont) A.Anaerobic Respiration A.Carried on by cells in absence of oxygen B.Performed in cytoplasm of cell C.Main source of energy for bacteria and fungi (yeast) D.Used to make foods such as cheese, yogurt, bread and wine

I. Cellular Respiration (cont) A.Two types A.Alcoholic Fermentation A.Glucose → 2 alcohol + 2 CO ATP B.Lactic Acid Fermentation A.Glucose → 2 Lactic Acid + 2 ATP B.Both are inefficient since alcohol and lactic acid have large amounts of unused energy (many bonds leftover)

I. Cellular Respiration (cont) A.Aerobic Respiration A.Carried on by cells in presence of oxygen B.Performed in mitochondria of the cell C.Glucose + O 2 → H 2 O + CO ATP D.More efficient than anaerobic respiration

II. Gas Exchange A.Respiratory System moves gases between external and internal surfaces for gas exchange B.Structures of Respiratory System A.Nasal Cavity – air goes through nostrils and enters cavity. Cavity is lined with mucous membranes that clean, warm and moisten air (uvula separates from throat)

II. Gas Exchange (cont) A.Pharynx – area where oral and nasal cavities meet B.Trachea – (windpipe) tube where air passes from pharynx to lungs A.Contains rings of cartilage that keeps trachea open B.Lined with cilia that trap particles in air and sweep it up to the pharynx to get coughed or sneezed out C.Contains epiglottis and larynx A.Epiglottis – covers opening of trachea during swallowing and opens during breathing B.Larynx – (voice box) produces speech

II. Gas Exchange (cont) A.Bronchi and Bronchioles – lower end of trachea splits forming 2 bronchi which are lined with mucous and ringed with cartilage. Bronchi separate into MANY bronchioles B.Alveoli A.Millions of alveoli are in the lungs B.Walls are thin and moist and surrounded by capillaries C.O 2 diffuses from lungs to blood and CO 2 + H 2 O diffuse from blood to lungs

II. Gas Exchange (cont)

III. Breathing A.Air moving in and out of the lungs B.Lungs A.No muscle but HIGHLY elastic. Expand and contract b/c of pressure changes in chest cavity (caused by actions of rib cage and diaphragm)

III. Breathing (cont) A.Inhalation A.Ribs up and out, diaphragm moves down. B.Enlarges chest cavity, makes LOW pressure, air goes in B.Exhalation A.Ribs down and in, diaphragm moves up. B.Decreases cavity, HIGH pressure, air out

III. Breathing (cont) High Low

IV. Breathing Rate A.Controlled by breathing center in medulla of brain B.Senses amount of CO 2 in blood. A.When amount is high, nerve signals (impulses) are sent to lungs and diaphragm to increase breathing rate B.When amount lowers, impulses are slowed, dec breathing rate C.This is a feedback mechanism

IV. Breathing Rate (cont)

V. Disorders A.Bronchitis – inflammation of bronchial tubes. Air passages become narrowed and filled with mucous, causing difficulty breathing and coughing

V. Disorders (cont) A.Asthma – an allergic reaction causing narrowing of bronchial tubes, difficulty in breathing

V. Disorders (cont) A.Emphysema – walls of alveoli break down, dec surface area for gas exchange, causing difficulty breathing and dec lung capacity (smoking can cause)