Unit 2 Flashcards
What is the role of the digestive system
break down and absorb food
Explain the function of an enzymes active site in a chemical reaction
Attach to the substrate to speed up the reaction
How can a student make sure all the test tubes in the same temperature in an experiment
Place them in a water bath
What is the product of the reaction catalysed by amylase
Sugars
Describe the role of digestive enzymes in the process of digestion
They breakdown big molecules from food into smaller soluble molecules that can pass easily through the walls of the digestive system, allowing them to be absorbed into the bloodstream
Give two ways in which the products of digestion can be used by the body
To make new carbohydrates, to make new proteins, some glucose is used in respiration, to make new lipids
Fully outline the processes involved in the digestion of a meal containing carbohydrates proteins and lipids (6)
Carbohydrate digestion begins in the mouth where amylase is produced by the salivary glands
Carbohydrate digestion also occurs in the small intestine which produces its own supply of amylase and contains amylase produced by the pancreas
Amylase converts carbohydrates into sugars
protein is digested in the stomach where protease is produced
Protein digestion also occurs in the small intestine, which contains proteases and also contains proteins produced by the pancreas
Proteases convert protein into amino acids
lipids are digested in the small intestine, which produces lipases and also contains lipases is produced by the pancreas
Lipase converts lipids into fatty acids and glycerol
The products of the digestion enzymes are absorbed by the bloodstream
What flows next to alveoli?
Capillaries
What role did capillaries play in gas exchange (4)
The capillary carries blood that is returning from the rest of the body and contains a higher concentration of carbon dioxide than in the lungs. The carbon dioxide diffuses into the alveoli where there is a lower concentration, to be breathed out. The capillary also picks up oxygen from the alveoli, which contains a high concentration of oxygen in the blood. Oxygen diffuses from the alveoli into the blood, to be carried to body cells.
Explain why the human circulatory system is described as a double circulatory system
It consists of two circuits joined together
The first circuit pumps deoxygenated blood to the lungs and Returns oxygenated blood to the heart
The second circuit pumps oxygenated blood to the muscles and Returns deoxygenated blood to the heart
Describe how the heartbeat is controlled
A group of cells in the right atrium wall at to the pacemaker
Explain how arteries are adapted to perform their function
Elastic fibres allow them to stretch and spring back
Arteries contain thick layers of muscles to make them strong
Why are the walls of capillaries only one cell thick
They carry blood close to cells to exchange substances
They also increase the rate of diffusion as there is less distance to travel
Explain how white blood cells are adapted to perform their function (3)
Some white blood cells can you change shape to engulf microorganisms via phagocytosis
Others produce antibodies to fight microorganism or antitoxins to neutralise any toxins produced by the microorganisms
Explain how red blood cells are adapted for their function
Concave dish shape carries more oxygen
No nucleus means It can carry more oxygen
It contains haemoglobin which binds to oxygen
