B2: Organisation Flashcards
What is a tissue?
A group of similar cells that work together to perform a specific function
Explain what is meant by the term ‘organ system’:
A group of organs working together to perform a specific function
Why can enzymes be described as biological catalysts?
They increase the speed of a reaction without being used up
Why do enzymes normally only catalyse one reaction?
Because the active site is only specific to one type of substrate
What does it mean when an enzyme has been ‘denatured’?
It cannot work any more as the active site has changed
List three places in the body where amylase is produced:
Saliva, pancreas and small intestine
What is the role of lipase?
Convert lipids into glycerol and fatty acids
Where is bile stored?
Gall bladder
Name the solution that you would use to test for the presence of lipids in a food sample:
Sudan III
Name the tubes that split off of the trachea:
Bronchi
Explain the role that alveoli play in gas exchange:
Oxygenation of the blood
Explain why the circulatory system in humans is described as a ‘double pump’:
Because there is actually two circuits joined together at the heart
Why does the heart contain valves?
To stop blood from flowing the wrong way
Name the four chambers of the heart:
Right atrium and ventricle, left atrium and ventricle
How is the resting heart rate controlled in a healthy heart?
Group of pacemaker cells in the wall of the right atrium
How are arteries adapted to carry blood away from the heart?
Strong and elastic walls to cope with high pressure blood flow
Why do red blood cells not have a nucleus?
More room to carry oxgen
Give two advantages and two disadvantages of statins:
Reduce the chance of strokes, and increase HDL cholesterol levels but they can cause liver problems and have to be taken regularly
What is the difference between biological and mechanical replacement heart valves?
Biological valves come from an animal whereas mechanical ones are man-made
What is meant by a non-communicable disease?
A disease that cannot be contracted from an infected organism
Give an example of where different diseases might interact in the body:
A problem with the immune system could lead to an increased chance of catching communicable disease
What is meant by a risk factor of a disease?
Risk factors increase your chance of getting a disease
Which type of tumour is cancerous?
Malignant tumour
List the tissues that make up a leaf:
Waxy cuticle, epidermal, palisade mesophyll and spongy mesophyll
Explain how the structure of the upper epidermal tissue in a leaf is related to its function:
It is transparent so that light can pass through to the palisade layer
What is the function of phloem?
Transporting sugars for storage and growth
What is transpiration?
The loss of water from the plant as a natural by-product of photosynthesis
List the four main factors that affect the rate of transpiration:
Light intensity, temperature, humidity and air flow
How could you measure the rate of transpiration?
By measuring the level of water uptake by a plant
