B8: Exchange And Transport In Animals Flashcards
What is respiration?
A process that releases energy in the form of ATP from the breakdown of organic compounds
What is ATP?
A short term energy store in all cells
What type of reaction is respiration
Exothermic reaction
Where do plants get the glucose required for respiration?
Photosynthesis
Where to animals get the glucose required for respiration?
From the breakdown of carbohydrates that they have ingested
What are the 2 types of respiration?
Aerobic and anaerobic
What is aerobic respiration?
Respiration in the presence of oxygen that forms ATP from the breakdown of glucose
What is anaerobic respiration?
Respiration that takes place without oxygen and forms APT from the breakdown of glucose
When does anaerobic respiration take place?
During vigorous exercise (in animals)
If the soil becomes waterlogged (in plants)
What are the symptoms of lactic acid build up ?
Cramp and fatigue
What is the circulatory system ?
Network of organs
Enables the flow of blood around the body
What are the 4 main Components of blood?
Red blood cells
White blood cells
Platelets
Plasma
What are the red blood cells also known as ?
Erythrocytes
What is the function of red blood cells ?
Transport oxygen from the lungs to tissues
Transport carbon dioxide from the tissues to the lungs
What are 3 adaptations of the red blood cells also known which makes it good for their function ?
- Biconcave disk which allows for more diffusion because of the larger surface area
- Small and flexible allowing them to move through the capillaries
- Thin giving a short diffusion distance
What is the function of a white blood cell ?
To provide protection against infection
What are the 2 types of white blood cell ?
Phagocytes
Lymphocytes
What are lymphocytes?
Produce antibodies specific to a pathogen
What are phagocytes?
Digest pathogens
What is the function of platelets?
To form blood clots
How is plasma adapted to its function ?
Plasma contains mainly water which acts as a solvent enabling the transport of material around the body
What are the three main type of blood vessel ?
Arteries
Capillaries
Veins
What is the function of the arteries?
Carry blood away from the heart under high pressure
How are the arteries adapted for there function ?
Narrow lumen
Thick wall
Thick layer of elastic fibres
Smooth inner lining
No valves
What is the function of the veins?
Return blood to the heart under low pressure
How are veins adapted for their function ?
Large lumen
Thin walls
Thin layer of smooth muscle and elastic fibres
Valves
What is the function of capillaries?
Allow exchange of materials at tissues
How are capillaries adapted to their function?
Large surface area
One cell thick wall
Permeable wall
Narrow lumen
What is the pulmonary circuit?
Part of the circulatory system involving the right side of the heart transporting deoxygenated blood to the lungs
What is the systemic circuit?
Part of the circulatory system involving the left side of the heart pumping oxygenated blood to the tissues in the body
Name the 4 chambers of the heart ?
Left atrium
Left ventricle
Right ventricle
Right atrium
What is the pathway of blood around the body ?
Pulmonary vein-left atrium-left ventricle-aorta-body-vena cava-right atrium-right ventricle-pulmonary artery-lungs
What is the function of valves ?
Prevent back flow
What factors affect rate of diffusion?
Diffusion distance
Concentration gradient
Surface area
Why is the left ventricle thicker than the right ventricle?
It pumps blood a further distance so it must generate a greater force of contraction so blood can be pumped at a higher pressure
What is cardiac output ?
The volume of blood pumped out of a ventricle in one minute
What is stroke volume ?
The volume of blood pumped out of a ventricle in one contraction
What is heart rate ?
The number of times the heart contracts in one minute
Why must respiration occur continuously in living cells?
ATP is required for many essential processes in living cells e.g movement
When may anaerobic respiration occur in plant cells?
If the soil becomes waterlogged
Is aerobic or anaerobic respiration more efficient?
Explain why?
Aerobic respiration is more efficient as it produces more molecules of ATP than anaerobic respiration.
Why do large multicellular organisms require specialised exchange surfaces?
• Small SA/V ratio
• Diffusion insufficient to provide all cells with the required oxygen and nutrients, and to remove all waste products
• Exchange surfaces increase rate of diffusion and shorten diffusion distance
Name some of the substances transported into and out of the human body?
Oxygen
Carbon dioxide
Water
Dissolved food molecules
Urea
Why do some multicellular organisms (e.g. trees) not require specialised exchange surfaces?
Trees have a large number of leaves which provide a large SA/V ratio for diffusion.
How does the size of an organism affect its surface area to volume ratio?
The larger the organism, the smaller the SA/V ratio.
How does oxygen enter and carbon dioxide leave cells?
They diffuse into and out of cells.
How does water enter cells?
It diffuses into cells by osmosis.
How do food molecules and mineral ions enter cells?
They are dissolved in water which diffuses into cells.
Why must urea be excreted from the body?
It is a waste product so must be excreted.
How is urea excreted from the body?
• Urea diffuses out of cells into the blood plasma
• The kidney filters urea out of the blood
• Urea is excreted in urine
Why must the human body exchange oxygen and carbon dioxide with the environment?
• Oxygen is required for respiration so diffuses into the body
• Carbon dioxide is a toxic waste product of respiration so diffuses out of the body
How does oxygen enter and carbon dioxide leave the bloodstream?
• Oxygen diffuses from air in the alveoli (high O, conc) into blood in the capillaries (low Oxygen , conc)
• Carbon dioxide diffuses from blood in the capillaries (high CO2, conc) into air in the alveoli (low CO2, conc)
How are alveoli adapted for gaseous exchange?
• Large surface area
• Network of capillaries provide a good blood supply
• Rapid blood flow maintains a steep concentration gradient
• Thin walls give a short diffusion distance
• Cell walls have partially permeable membranes enabling diffusion
• Moist lining, enables gases to dissolve
How does diffusion distance affect the rate of diffusion?
The greater the diffusion distance, the further the molecules must travel and the slower the rate of diffusion.
How does concentration gradient affect the rate of diffusion?
The steeper the concentration gradient, the faster the rate of diffusion.
How does surface area affect the rate of diffusion?
The larger the surface area, the greater the number of molecules that can diffuse across in a given time, so the faster the rate of diffusion.
