Mass transport in animals

• Water is a polar molecule, explain what this means?

  it has a positively charged end and a negatively charged end (the oxygen is slightly negative and the hydrogens are slightly positive) due to the electro negativity of oxygen meaning electrons are closer to oxygen in the covalent bonds
• Which of the carbon compounds will not form hydrogen bonds with water and will therefore not dissolve?

  Propane (non-polar)
• Which carbon compound will not form hydrogen bonds in water and will therefore not dissolve?

  propane

  
• explain how hydrogen bonds form?

  they form between oxygen and hydrogen atoms (or between atoms with a large difference in electro negativity)

  between the slightly negative end and the slightly positive end
• Apart from water, give three other examples of hydrogen bonding in biological molecules?

  DNA, proteins in secondary structure between amino groups

  and carboxyl group in backbone, and in tertiary structure between R groups , and cellulose.
• Describe the formation of hydrogen bonds between molecules of water?

  Between the hydrogen and oxygen in a water molecule

  between delta positive and delta negative

  because there is a separation of charge causing water to be a polar molecule
• Why will ionic compounds dissolve in water?

  Water is a polar molecule and ions have charges, so Hydrogen bonds in water are stronger than forces between ions and can therefore attract individual ions And surround them
• Describe blood circulation in fish

  Deoxygenated blood pumped by heart through vessels to gills

  in gills, blood passes through capillaries, and oxygen diffuses from oxygenated water to deoxygenated blood

  oxygenated blood passes from gills to body tissues through blood vessels

  At body tissues, the oxygenated blood passes through capillaries and diffuses to cells

  deoxygenated blood returns back to the heart to be pumped to gills

  
• what type of circulatory system do fish have?

  closed, single
• What is the problem with the single circulatory system in fish?

  blood is at a high pressure when being pumped by heart, however passes through 2 sets of very narrow capillaries, causing blood to lose pressure and slow down. This means that blood is moving slowly, limiting how rapidly oxygen can be delivered to body cells. This means that fish are not adapted for sudden changes in metabolic rate.

  
• define a single circulatory system?

  Blood flows through the heart once per cycle, meaning that it flows at a low pressure and is suitable for organisms with a low metabolic rate
• define double circulatory system?

  A circulatory system in which blood flows through the heart twice in one complete circuit of the body, it pumps to the body and to the lungs simultaneously, meaning it is efficient. maintains a high blood pressure
• What is an open circulatory system?

  Transport medium is not enclosed, and moves in open spaces. Better for small organisms in which blood does not need to travel over long distances
• Define closed circulatory system?

  blood is enclosed in vessels, diffusion always occurs in capillaries
• How does blood circulate in an open Circulatory system?

  blood moves into cavities surrounding organs, substances diffuse Into tissue and the heart relaxes, lowering blood pressure in the heart, so the blood in cavities is forced back into the heart through valves
• What are the advantages of closed circulatory systems?

  blood always travels in narrow vessels, meaning it is kept at a high blood pressure, and can travel large distances. Furthermore vessels can constrict or dilate in order to control how many nutrients are delivered to certain areas
• what is mass transport?

  a transport medium such as blood is involved in the bulk movement of dissolved substances from exchange surfaces to body tissues. Mass transport maintains concentration gradient and removes waste.
• Suggest the advantages of a human circulstory system over a fish?

  humans have a double circulatory system, meaning they pass through the heart twice. Blood is pumped at a greater pressure to the body meaning reduced damage to lungs and blood moves more rapidly to Body, allowing for more efficient gas’s exchange
• Explain why the insect does not need to have a closed circulatory system

  The insect is small, so it has a large surface area to volume ratio

  This means substances can easily diffuse around the body as the cells are very close to the heart (short diffusion distance)

  This means that diffusion is fast enough for diffusion, and blood vessels are not Required as fluid does not need to move large distances

  
• • Flatworms do not have a circulatory system or a heart. explain why many animals needed a heart and circulatory system?

  -many animals have a low surface area to volume ratio

  -this means that diffusion distance Will be too large, and aniMacs cannot depend on diffusion alone for the movement of gases

  -so they require an exchange surface with a high surface area to volume ratio

  -a transport medium for the bulk movement or substances

  -a heart to pump blood around the body at a high pressure

  -a circulatory system to maintain high blood pressure and concentration gradient
• Giraffes are very tall mammals. Explain the need of a heart and a circulatory system to a giraffe?

  The heart has to pump blood a very large distance, and therefore this blood must be at a high pressure so that it travels quickly

  so a closed circulatory system is needed to contain the blood in narrow vessels to maintain high blood pressure

  Giraffes also have a double circulatory system to meet high metabolic needs, as it pumps blood twice

  Circulatory system is needed for mass transport for the bulk movement of glucose and oxygen to cells and waste out of cells