Biología

Biology Notes 4
Respiration
Cellular respiration: mitochondrion- multi membrane organelle, has ability to pump protons across membrane
Proton is a hydrogen ion, cannot go through membrane- they need help
* ATP synthase allows protons to pass thru
* Requires glucose
* Need oxygen in final steps to produce ATP
1. Done by mitochondria
a. Mitochondria located incells
2. Mitochondria requires oxygen
3. Generates carbon dioxide as a waste
4. ATP (energy) generated during this process

Glucose is a 6 carbon sugar
Carbon comes from the nutrients you intake

Respiratory system
1. Requires large, moist surface area
2. Blood and external environment interact
3. Exchange of oxygen and CO2
4. Gases dissolve in moisture easier, thenexchange

Evolution of respiratory system:
1. No respiratory or circulatory system
a. Small, thin animals in moist environments (nematodes or flatworms; large, moist external surface area for gas exchange)
b. Jellyfish lack both
2. Circulatory but no defined respiratory system
c. Earthworms have a well-developed, closed circulatory system to carry gases throughouttheir bodies. Still rely on diffusion in/out of circulatory system through moist skin surface.
3. Respiratory and circulatory systems (humans)
d. Don’t need moist exterior, but surface where gas exchange occurs (lungs) is still moist to help diffuse gases
e. Air moves by bulk flow (large amounts over long distances)
f. Diffusion (individual molecules over short distances,<<<1mm)
i. Movement of substances from high to low concentration
ii. Oxygen and CO2 diffuse in and out of blood stream
iii. Carbon dioxide is a waste product of cellular respiration
g. Three types:
1. Gills (aquatic animals)
a. Contain dense profusion of capillaries inside filaments
b. Operculum (covers gills); fish “gulp” water tokeep from moving across gills
2. Tracheae (in insects)
3. Lungs
c. Delicate, moist chambers deep in the body
d. Development simple to complex depending on organism

Mammalian respiratory system:
1. Conduction portion that carries air into lungs
a. Mouth and nose -> pharynx (chamber where mouth and nose meet)
b. Pharynx -> larynx (first part ofpathway exclusive for gas flow, NO FOOD!), houses vocal chords
c. Larynx-> trachea (rigid tube leading to lungs, cartilage rings provide support/flexibility)
d. Trachea -> bronchi (2 branches)
e. Bronchi -> bronchioles (branch again, smaller)
f. Bronchioles -> alveoli (small sacs inside lungs)
i. Mucus (traps dust, either swallowed or coughed up)2. Gas exchange portion
g. Alveoli (end of each bronchiole, “grapes”),gases exchange by diffusion here, surrounded by capillaries
h. Emphysema: disease when alveoli become brittle and rupture, decreased area for gas exchange results
i. Movement of oxygen from the outside air to respiratory surfaces by ventilation of the lungs is an example of bulk flow

Mechanics ofbreathing:
* Inhalation (muscles contract)
* Diaphragm (muscle) and pleural membrane surround lungs
1. Diaphragm goes down and muscles around the ribs life them out and up
2. Creates a vacuum that causes lungs to expand and draw air
* Exhalation: air is passively exhaled (muscles relax)
1. Diaphragm and muscles relax
2. Lungs shrink, releasing air

Diseases associated withrespiration include lung cancer and emphysema. Both are induced by smoking cigarettes.
* By the time they start to experience symptoms it is too late to fix the problem
* Tumor has metastasized
* When you smoke, you start to suffocate
Did you know…
After just 20 minutes after your last cigarette your body begins a series of changes to repair the damage caused by smoking. In many...