Topic 8: Exchange and Transport in Animals Flashcards
What is aerobic respiration?
Respiration in the presence of oxygen that releases energy from the breakdown of glucose. Overall: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
What are alveoli?
Tiny air sacs in the lungs that serve as the gaseous exchange surface. They are adapted for exchange by having a large surface area, good blood supply, thin walls and a moist lining.
What is anaerobic respiration?
Respiration that takes place without oxygen and forms energy from the breakdown of glucose. In animals, lactic acid is produced. In plants, ethanol and carbon dioxide are produced. Less energy is formed than in aerobic respiration.
What is the aorta?
The artery that takes oxygenated blood away from the heart to the body.
What is an artery?
A type of blood vessel that carries blood away from the heart to the tissues, under high pressure. The walls of the arteries contain thick layers of smooth muscle and elastic fibres.
What are bicuspid valves?
The valves found between the left atrium and left ventricle.
What is blood?
A tissue containing red blood cells, white blood cells, platelets and plasma.
What are capillaries?
Thin, narrow blood vessels that connect the arteries and veins. They are the site of exchange of substances between the blood and the tissues.
What is cardiac output?
The volume of blood pumped out of a ventricle in one minute. It is calculated using: cardiac output = heart rate × stroke volume
What is cellular respiration?
An exothermic reaction that releases energy from the breakdown of organic compounds such as glucose. There are two types, aerobic and anaerobic.
What is the circulatory system?
The transport system in animals.
What is a concentration gradient?
The difference in concentration between two areas. The greater the concentration gradient, the faster the rate of diffusion.
What is diffusion?
The net spreading out of particles from a high concentration to a lower concentration (down their concentration gradient).
What is diffusion distance?
The distance that substances must diffuse. The smaller the diffusion distance, the faster the rate of diffusion.
What is a double circulatory system?
A circulatory system found in mammals in which the blood flows through the heart twice in two circuits. Blood is pumped from the heart to the lungs before returning to the heart. It is then pumped around the body, after which it returns to the heart again.
What is an erythrocyte?
A type of blood cell that is anucleate and biconcave. It contains haemoglobin which enables the transport of oxygen and carbon dioxide to and from the tissues.
What is an exchange surface?
A surface over which materials are exchanged.
What is Fick’s law?
States that the rate of diffusion is proportional to the surface area and difference in concentration, but is inversely proportional to the thickness of the membrane: surface area x concentration difference / thickness of membrane
What is heart rate?
The number of times the heart contracts in one minute.
What is lactic acid?
The product of anaerobic respiration in animal cells. Lactic acid build-up inhibits anaerobic respiration and results in cramp and fatigue.
What is a lymphocyte?
A type of white blood cell that produces antibodies (specific to a particular antigen) and antitoxins.
What is a multicellular organism?
An organism that consists of more than one cell. It has a small surface area to volume ratio, so diffusion is insufficient to provide all cells with the required oxygen and nutrients, and to remove all waste products. Multicellular organisms require an exchange surface and a mass transport system.
What is a phagocyte?
A type of white blood cell that engulfs pathogens and digests them in a process known as phagocytosis.
What is plasma?
The main component of the blood that carries red blood cells. It is a yellow liquid that contains proteins, nutrients, mineral ions, hormones, antibodies, antitoxins, dissolved gases and waste.
