2-Organisation Flashcards
What is a tissue
A group of similar cells that work together to carry out a particular function
What is an organ
A group of different tissues that work together to perform a certain function
What is an organ system
A group of organs working together to perform a particular function
What is an enzyme
A biological catalyst
What is a catalyst
A substance which increases the speed of a reaction without being changed or used up
What is the active site
Area in the enzyme where the substrate goes into
How does pH and temperature affect enzymes
If they get too high or too low then the enzyme denatures
Where is amylase produced
Salivary glands
Pancreas
Small intestine
Where is protease produced
Stomach
Pancreas
Small intestine
Where is lipase produced
Pancreas
Small intestine
What does starch break down into
Glucose and other sugars
What does protein break down into
Amino acids
What do lipids break down into
Glycerol and fatty acids
What is the role of bile
Neutralises the HCL in the stomach because enzymes work best in alkaline conditions
Emulsifies fats- breaks down fats into tiny droplets so there is a bigger SA
Where is bile produced and stored
Produced in the liver and stored in the gall bladder
What is the role of the large intestine in digestion
Where excess water is absorbed from food
What is the role of the small intestine in digestion
Produces protease, amylase and lipase enzymes
Digested food is absorbed out of the digestive system into blood
What is the role of the stomach In digestion
Pummels the food with the muscular walls
Produces protease and pepsin
Produces HCL to kill bacteria and make it pH 2 for the protease enzyme to work
What is the role of the pancreas in digestion
Produces protease, amylase and lipase which is released into the small intestine
What is the role of the liver in digestion
Where bile is produced.
What is the role of the rectum in digestion
Where the faeces are stored
What is used to test for sugars
Benedict’s solution
What colour does benedicts turn if sugar is present
Changes from blue to green, yellow or brick red depending on how much sugar is in the food
What is used to test for starch
Iodine solution
What colour does iodine turn if starch is present
Changes from browny-orange to black or blue black
What is used to test for proteins
Biuret solution
What colour does biuret turn if protein is present
Changes from blue to purple
What is used to test for lipids
Sudan III
What colour does Sudan III change to if lipids are present
The mixture will separate into two layers and the top layer will be bright red
How do u prepare a food sample
Break up the piece of food using a pestle and mortar
Transfer into beaker and add distilled water
Stir with glass rod
Filter out solid bits with a funnel and filter paper
What separates the thorax and lower part of your body
The diaphragm
What r the different tubes going in the lungs
Trachea
Bronchi
Bronchioles
Alveoli
How does gas exchange occur in the alveoli
Blood containing lots of CO2 and little O2 passes by the alveoli in capillaries.
CO2 diffuses out of blood into alveolus.
O2 diffuses out of alveoli into the blood
What is the circulatory system made up of
The heart, blood vessels and blood
What is the role of valves
To prevent backflow
What is the journey of blood on the right side of the heart
Enters from vena cava
Right atrium
Right ventricle
Exits through pulmonary artery
What is the journey of blood on the left side of the heart
Enters from the pulmonary vein
Left atrium
Left ventricle
Aorta
What is the role of arteries
Carry blood away from the heart
What is the role of veins
Carry blood to the heart
What is the role of capillaries
Involved in the exchange of materials at the tissues
What is the structure of arteries
Blood is high pressure so the walls are strong and elastic and thick compared to the size of the lumen
What is the lumen
The hole in the middle of a blood vessel
What is the structure of veins
Blood is at lower pressure so the walls aren’t as thick
Larger lumen
Valves
What is the structure of capillaries
Very thin walls- only one cell thick
Very small lumen
Permeable walls
What is the role of red blood cells
Carry oxygen from the lungs to the rest of the body
Contain haemoglobin which binds to oxygen
How r red blood cells adapted to carry more oxygen
No nucleus so more space
Biconcave structure for more SA
What is the role of white blood cells
Phagocytes engulf microorganisms
Lymphocytes produce antibodies
Have a nucleus
What is the role of platelets
Small fragments of cells that help blood clot at a wound, which stops blood pouring out and microorganisms getting in
What is the role of plasma
Straw coloured liquid carries- red blood cells, white blood cells, platelets, nutrients like glucose and amino acids, CO2, urea, hormones, proteins, antibodies and antitoxins
What is coronary heart disease
When the coronary arteries get blocked by layers of fatty materials building up and there is lack of oxygen
What r stents
Tubes inserted inside the arteries that keep them open
What r statins
Drugs that reduce the amount of LDL or ‘bad’ cholesterol in the bloodstream
Advantages of statins
Reduce risk of stokes, heart attacks and coronary heart disease.
Increases the amount of beneficial HDL cholesterol in bloodstream.
May also help to prevent other diseases
Disadvantages of statins
Long term drug and could be forgotten.
Takes time for effect to kick in.
Side effects: headaches, kidney failure, liver damage and memory loss
Advantage of artificial hearts
Less likely to be rejected as they are made of plastics or metals
Disadvantage of artificial heart
Surgery can lead to bleeding and infection, blood doesn’t flow as easily which can lead to blood clots and stokes so patient need to take pill to thin their blood, this could problems with bleeding if they get hurt in an accident
What is artificial blood used for
It is a salt substitute that is used to replace the missing volume of blood which can give the body time to produce new red blood cells
What is a communicable disease
Spread form person to person or between animals and people.
eg. Measles or malaria
What is a non-communicable disease
Can not spread between animals or people. Generally last a long time and get worse.
eg. Asthma, cancer and coronary heart disease
What r risk factors
Factors that increase the likelihood that a person will develop a certain disease during their lifetime
What r the costs of non-communicable diseases
Human cost- tens of millions die each year
Financial cost- NHS, and any other health services across the world, research and treatment costs are massive
What is uncontrolled growth and division a result of
Changes to cells that result in a tumour
What does benign mean
Tumour grows until there’s no more room then stops. Stays in one place.
Not cancerous
What does malignant mean
Tumour grows and spreads to neighbouring healthy tissues. Cells can travel in the bloodstream and form secondary tumours elsewhere
What risk factors can increase chances of cancer
Smoking Obesity UV exposure Viral infection Inherited faulty genes Mutations in the BRCA genes
What is epidermal tissue
This covers the whole plant and has a waxy cuticle which reduces water loss
What is palisade mesophyll tissue
This is the part of the leaf where most photosynthesis occurs and contains lots of chloroplasts. Near the top of the leaf where it can get most light
What is spongy mesophyll tissue
Contains big air spaces to allow gases to diffuse in and out of cells
What is meristem tissue
Found at the growing tips of shoots and roots and is able to differentiate into lots of different types of plant cell
Function and structure of phloem
Transport food substances mainly dissolved sugars
Columns of elongated living cells with small pores in the end walls for cell sap.
Transport goes in both directions.
Translocation
Function and structure of xylem
Carry water and mineral ions from roots to stems and leaves.
Made of dead cells with no end walls but a hole down the middle.
Strengthened with lignin.
Transpiration
What is transpiration
Loss of water from leaves through evaporation and diffusion
What is transpiration rate affected by
Light intensity
Temperature
Air flow
Humidity
How can you estimate the rate of transpiration of a plant
Measure the water uptake of the plant as it is directly related
When do guard cells become flaccid
When the plant is short of water the guard cells lose water and make the stomata close. This helps stop too much water vapour escaping
When do guard cells become turgid
When the plant has too much water and the guard cells fill, making the stomata open so gases can be exchanged for photosynthesis
