2. Structure and function in living organisms (f and g) Flashcards
How is ATP produced?
Respiration
What does ATP do?
Provides energy for cells
What is aerobic respiration?
Breakdown of Glucose in the presence of Oxygen to produce Carbon Dioxide and Water to release energy; occurs in the Mitochondria of the cell
What is anaerobic respiration?
Breakdown of Glucose in the absence of Oxygen to produce Lactic acid (and small amounts of energy) in humans, and Carbon dioxide and Ethanol (and small amounts of energy) in yeast and plants; occurs during exercise and causes cramps in humans (due to build-up of Lactic acid)
What is the equation for aerobic respiration?
Glucose + Oxygen → Carbon Dioxide + Water
What is the equation for anaerobic respiration in humans?
Glucose → Lactic Acid
What is the equation for anaerobic respiration in yeast and plants?
Glucose → Ethanol + Carbon Dioxide
What is the word equation for aerobic respiration?
Glucose + Oxygen –> (energy released) Carbon Dioxide + Water
What is the balanced equation for aerobic respiration?
C6H12O6 + 6O2 –> (energy released) 6CO2 + 6H2O
Describe the structure of the ribs in the thorax:
The bone structure that protects internal organs including the Lungs
Describe the structure of the intercostal muscles in the thorax?
Muscles between the Ribs that move ribcage during inhalation and exhalation
Describe the structure of the diaphragm in the thorax:
Sheet of muscle at bottom of Thorax that changes the thoracic volume during inhalation and exhalation
Describe the structure of the trachea in the thorax:
Windpipe that connects the Mouth and Nose to the Lungs
Describe the structure of the bronchi in the thorax:
Thick tubes that divides into two Bronchi inside Lungs - one Bronchus for each Lung
Describe the structure of the bronchioles in the thorax:
Bronchi will split to form thinner tubes called Bronchioles that are connected to Alveoli
Describe the structure of the alveoli in the thorax:
Tiny air sacs where gas exchange occurs
Describe the structure of the pleural membrane in the thorax:
Thin, moist membrane lining the outside of Lungs for lubrication to reduce friction, and to stick outside of Lungs to chest cavity for Lung to follow chest movement
How do the intercostal muscles play a role in inhaling?
During inhalation
- The diaphragm contracts and flattens
- The external set of intercostal muscles contract to pull the ribs up and out:
- This increases the volume of the chest cavity (thorax)
- Leading to a decrease in air pressure inside the lungs relative to outside the body
- Air is drawn in
How do the intercostal muscles play a role in exhaling?
During exhalation
- The diaphragm relaxes it moves upwards back into its domed shape
- The external set of intercostal muscles relax so the ribs drop down and in
- This decreases the volume of the chest cavity (thorax)
- Leading to an increase in air pressure inside the lungs relative to outside the body
- Air is forced out
What are alveoli?
Tiny air sacs where gas exchange occurs
How have alveoli adapted for gas exchange?
- most cell walls
- thin cell walls
- large surface area
- dense capillary network
How does moist walls increase the rate of diffusion in the alveoli?
gases dissolve in the moisture helping them to pass across the gas exchange surface..
How does thin cell walls increase the rate of diffusion in the alveoli?
Thin cell walls (one cell thick) to minimise distance of diffusion of gases, therefore increasing the rate of gas exchange
How does a dense capillary network increase the rate of diffusion in the alveoli?
Alveoli surrounded by dense capillary network to provide rich blood supply and creates a strong concentration gradient for the diffusion of gases, therefore increasing the rate of gas exchange
What can smoking cause?
Smoking causes chronic obstructive lung disease (COPD), coronary heart disease and increased risks of several different types of cancer, including lung cancer
What are some chemicals in cigarettes?
- Tar - a carcinogen (a substance that causes cancer)
- Nicotine - an addictive substance which also narrows blood vessels
- Carbon monoxide - reduces the oxygen-carrying capacity of the blood
How does smoking effect the air passages?
- Tar in cigarettes destroy the Cilia (which carries away dust and microbes trapped in Mucus), therefore causing the buildup of - Mucus and increasing risk of Bronchitis
- Tar in cigarettes contain carcinogens that increases risk of Lung Cancer
How does smoking effect alveoli?
- Tar in cigarettes break down Alveoli walls and causes them to merge together, decreasing the surface area to volume ratio for gas exchange
- Insufficient gas exchange will increase the risk of Emphysema - shortness of breath due to insufficient Oxygen transport in blood
How does smoking effect the circulatory system (nicotine)?
Nicotine in cigarettes causes blood vessels to narrow, placing strain on circulatory system and results in the increase in blood pressure
- Narrowing of blood vessels also causes the build-up of Fat globules, increasing risk of Coronary Heart Disease (CHD)
- CHD involves the blockage of Coronary Artery by Fat globules (forming plaques), causing insufficient Oxygen transport in blood leading to increased anaerobic respiration (due to lack of Oxygen)
- Increase in anaerobic respiration causes build-up of Lactic acid which creates acidic environment for enzymes to denature, hence causing strokes
How does smoking effect the circulatory system (Carbon Monoxide)?
Carbon Monoxide from cigarette smoking will bind irreversibly to Haemoglobin, reducing capacity of Oxygen transport by Red blood cells and hence increases the risk of Emphysema - shortness of breath due to insufficient Oxygen transport in blood
