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Flashcards in Unit 2 Deck (27)
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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



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?



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



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

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