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
Describe the structure and form of platelets
Small Fragments of cell with no nucleus
Platelets help blood clot and stop bleeding
Explain how statin slow down the progression of coronary heart disease
They reduce the amount of bad cholesterol which slows down the rate of fatty deposit
A patient is offered statins suggest one reason why he may not wish to take them
He is worried about the side effects
Describe two ways a valve may be faulty
It may not be opened fully or it might become Leakey
List two lifestyle factors that can cause ill health
Diet
stress
What is meant by a risk factor of a disease
Something that is linked to an increase in the likelihood that a person will develop a certain disease during their lifetime
State three types of risk factors
Lifestyle
Substances in body
Substances in the environment
Suggest two reasons why non-communicable disease can be financially costly
The cost of researching and treating Can be massive.
If someone has to give up work, the income is reduced.
Name two substances that are transported around a plant in the xylem.
Water and mineral ions
Name two sites in a plant where you would find meristem tissue
Tips of roots and tips of shoots
Give one reason why meristem tissue is important throughout the life of a plant
It can differentiate into lots of different types of plant cells
What is the function of air spaces in leaves
Increase the rate of diffusion of gases
