Organsiation Flashcards
(83 cards)
1
Q
Explain Cancer
A
When cells divide uncontrollably by mitosis and create new cells the body doesn’t need.
A group of these cells is a tumour
2
Q
Difference between a benign and malignant tumour
A
B= grows slowly, usually within a membrane so can be removed and does not invade the rest of the body
M=grows quickly, invades neighbouring tissue and can spread to different areas of the body through the blood stream
-can form secondary tumours in other areas of the body (metastasis)
3
Q
Causes of cancer
A
- carcinogens= damage DNA, cause mutations, when there are several risk increases
e. g. cigarette smoke - alcohol
- ionising radiation e.g. sunbeds
- poor diet, high fat or salt intake
4
Q
Ways smoking can cause cardiovascular disease
A
- damages lining of coronary arteries, encourages build up of fatty material
- carbon monoxide reduces amount of oxygen that can be carried
- nicotine increases heart rate,strain on heart
- can increase blood clotting
5
Q
Ways smoking can cause lung diseases (COPD)
A
- destroys alveoli in the lungs
- airways become inflamed and mucus builds up
- carcinogenic chemicals
6
Q
How alcohol damages the liver
A
- causes lipid build up (fatty liver disease)
- alcoholic hepatitis (inflammation of the liver), can be fatal
- cirrhosis can cause liver to loose it’s ability to function
7
Q
Effects of obesity
A
- high blood pressure
- fatty deposits in the arteries, can cause cardiovascular disease
- increases risk of diabetes
8
Q
Type 2 diabetes
A
when the body stops responding to insulin effectively or at all
9
Q
Two transport systems in a plant
A
Xylem =water and minerals
Phloem =sugars and amino acids dissolved in water
10
Q
How plant leaves are adapted for gas exchange and photosynthesis
A
- large surface area= absorption of light and carbon dioxide
- thin= limited distance for diffusion
- air spaces between cells= diffusion of gases
11
Q
Palisade mesophyll
A
Plant tissue containing closely packed cells on the upper layer of a leaf
12
Q
Structures in a leaf
A
- upper and lower epidermis
- palisade and spongy mesophyll
- guard cells with chloroplasts
- waxy cuticle
13
Q
How palisade mesophyll absorbs light effectively
A
- lots of chloroplasts arranged closely together
- on the upper surface of the leaf
14
Q
Spongy mesophyll
A
Plant tissue in a leaf with loosely packed cells and air spaces to allow gas exchange
15
Q
How spongy mesophyll is efficient for gas exchange
A
- packed together loosely
- cells covered in a layer of water for gases to dissolve into and move in and out of the cells
16
Q
Xylem vessels
A
Narrow, hollow, dead tubes responsible for the transport of water and minerals in plants
17
Q
Phloem
A
Tissue in plants that transports the products of photosynthesis such as sugars and amino acids
18
Q
Sieve tubes
A
Conducting cells that make up the phloem
19
Q
Companion cells
A
Cell that lies alongside a sieve tube and provides the sieve tube with energy to transport sugars and amino acids in solution
20
Q
Difference in transport in the xylem and phloem
A
X=physical process, transports water and minerals, only upwards
P=requires energy, transports products of photosynthesis, transports upwards and down
21
Q
Transpiration
A
Loss of water from leaves by evaporation through stomata
22
Q
Uses for water in a plant
A
- photosynthesis
- transport of mineral ions
- cools the leaf as water evaporates
- keeps cell turgid (enlarged and swollen with water)
23
Q
Epidermal cells
A
The outer covering of a layer of an organism
24
Q
Factors effecting transpiration
A
- temperature
- humidity
- air movement
- light intensity
25
Factors effecting water loss from the leaf
- temperature
- air movement
- obstruction of the stomata
26
Method for investigating water loss through stomata using petroleum jelly
1. Get 4 leaves from the same bush or tree
2. Measure the mass of each one
3. Coat 1 with jelly on the upper leaf, 1 on the lower, 1 on both sides and 1 on none
4. Suspend the leaves using string
5. After a set amount of time remeasure the masses
27
What is a potometer
A tube device used to measure the uptake of water of a leaf shoot
28
Why scientists would count the number of stomata on a leaf
- to investigate the difference in number, density and distribution on the upper and lower leaf
- to investigate how many are open and closed at a certain time
- to see adaptations of the plant from environmental conditions
29
Substances transported in the blood
- oxygen =from the lungs to the rest of the body
- CO2=from the rest of the body to the lungs
- glucose=digestive system to the liver then to the rest of the body
- urea= liver to the kidneys
- antibodies + hormones
30
The hearts four chambers
- right and left ventricle
| - right and left atrium
31
Bloods movement through the heart in one circulation around the body
- deoxygenated blood from the body enters the right atrium
- passed through the right atrium to the left ventricle and then to the lungs through the pulmonary artery
- oxygenated blood from lungs enters left atrium through pulmonary vein
- passes through the left ventricle through the aorta and to the rest of the body
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Function of a valve
To prevent blood in the veins flowing in the wrong direction
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How a valve may be faulty
- not opening wide enough therefore restricting blood flow through the heart
- not closing properly and allowing blood to leak back though into the atrium
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Symptoms of faulty valves
- shortness of breath
- dizziness
- rapid heart rate
- chest pain
- can lead to heart failure
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Treatments for faulty valves
- have either a human donor or have one made from tissues from pigs or cows
- mechanical valves (last longer, but can cause blood clots)
36
What controls heart rate
Specialised cells in the right atrium generate electrical signals to make the heart contract
- separate from the nervous system
- allows the ventricles to contract together
37
Artificial pacemaker
A battery operated device implanted in the chest that sends out regular electrical impulses to make the heart contract normally
38
Arteries
Blood vessels that carry blood away from the heart
| -has thick walls to deal with high pressure
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Veins
Blood vessels with valves that transport blood to the heart
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Capillaries
Tiny blood vessels with one cell thin walls where exchange of material occurs
-connect
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Differences between arteries and veins
A= carries oxygenated blood, except pulmonary, carries blood under high pressure, has thick muscular walls, has connective tissue to provide strength, channel carrying blood is narrow (lumen)
V=carries deoxygenated, except pulmonary, carries blood under low pressure, thinner walls, less connective tissue and a wide lumen.
42
Plasma
Liquid in blood that contains glucose, amino acids, minerals, nutrients and hormones as well as waste materials
43
Components of blood and their functions
Red blood cell=transports oxygen
White blood cell=ingests pathogens and produces antibodies
Platelets= involvement in blood clotting
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Haemoglobin
Red protein in red blood cells that transports oxygen around the body
45
Red blood cells
- no nucleus, more space for haemoglobin
- small and flexible to fit through capillaries
- disc shaped to maximise surface area
- thin for short distance for oxygen to diffuse through
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Phagocytes
- make up about 70% of white blood cells
- engulf and destroy unwanted microorganisms (phagocytosis)
- part of the immune system
47
Lymphocytes
- produce antibodies when a foreign body enters the body
| - also part of the immune system
48
Platelets
- produced by cells in the bone marrow
- have proteins that enable them to stick and clump together to breaks in a blood vessel
- secrete proteins that result in chemical reaction that make blood clot to plug wounds
49
Coronary heart disease
When the Coronary artics that supply blood and oxygen to the heart muscle become blocked by fatty material causing them to narrow.
50
Treatments for coronary heart disease
Statins= drugs to help lower cholesterol by lowering its production in the liver
-may have side effects such as memory loss, linked with type 2 diabetes and liver damage
Stents=a wire mesh tube that helps open the coronary arteries
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Immunosuppressant drugs
Drugs that prevent a patients immune system rejecting a transplant
52
Carbohydrates
- source of energy, glucose
- starch found in potatoes, rice , bread and pasta e.t.c
- sugars found in fruit, sweets, chocolate e.t.c
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Proteins
- used for growth and repair
| - found in meats, eggs, cheese, nuts e.t.c
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Lipids
- used for energy and makes up part of the cell membrane so essential for growth
- found in butter, processed meats, plant oils, oily fish e.t.c
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Cellulose
Forms cell wall in plants, is a carbohydrate
| -cannot be broken down by digestive system so egested by gut
56
Protein synthesis
The production of proteins from amino acids after they were broken down to pass through the gut wall
57
Test used to detect sugars
Benedict’s solution
58
Method for testing for sugars
- add Benedict’s solution to a food in a test tube
- heat the tube in a water bath
- record the colour the solution turns which depends on the amount of glucose present.
- will normally go a red-brown
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Method for testing for starch
- add iodine solution to the food
| - if it contains starch it will go a blue-black colour
60
Method for testing for proteins
- add 1cm cubed of buiret solution A to the food solution
- mix the two liquids
- add 1cm cubed of biuret solution B and shake
- if protein is present the solution will either turn purple or there will be a purple ring between the layers of the liquids.
61
Emulsion test to test for lipids
- ethanol added to a test tube containing the crushed food
- this mixture is added to a second tube containing water
- if the liquid turns cloudy there is a presence of lipids.
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Role of the mouth in the digestive system
Begins the digestion of carbohydrates
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Role of the stomach in the digestive system
Begins digestion of protein and small molecules are absorbed
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Role of the small intestine in the digestive system
Completes digestion of carbs and proteins into simple sugars and amino acids
- absorption of single sugars, amino acids, fatty acids and glycerol
65
Role of the large intestine in the digestive system
Absorbs water, egests undigested food
66
Villi
Projections in the small intestine that provide a large surface area for food to be absorbed
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Enzymes
protein that speeds up a chemical reaction
68
Active site of an enzyme
We’re the specific substrate fits so the chemical reaction can take place and it can be broken down
69
Factors effecting enzyme action
-temperature= low temp results in less successful collisions between enzymes and substrates
=high temp disrupt the shape of the active site and denature the enzyme and prevent it from working
-change in pH levels= the amino acids in chains in the enzyme may become not attracted t each other anymore and change the shape of the active site
70
Optimum pH of different enzymes
Salivary amylase = 6.8
Stomach protease = 1.5-2
Pancreatic protease = 7.5-8
71
Enzyme that breaks down carbohydrates
Carbohydrase= carbs - simple sugars
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Enzyme that breaks down starch
Amylase = starch - glucose
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Enzyme that breaks down proteins
Protease = protein - amino acids
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Enzyme that breaks down lipids
Lipases = lipids- fatty acids + glycerol
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Were proteases are produced
Stomach + small intestine
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Were amylase is produced
Mouth + small intestine
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Were lipases are produced
Small intestine
78
Method for investigating effect of pH on rate of reaction of Amylase enzyme
- series of test tubes containing amylase, starch and a buffer solution are set at different pH levels
- sample removed from the test tubes every 10 seconds to test the presence of starch
- iodine solution will turn blue/black if starch is present so when the starch has been all broken down the solution will remain red/brown.
79
Function of bile
- Emulsifies lipids (to mix water with them) which breaks them up into tiny droplets which increases their surface area and allowed lipases to work.
- neutralises stomach acids
- is stored in gall bladder
80
Organisms are made up of… (from smallest to largest)
Organelles , cells , tissues , organs , organ systems
81
Organelle
Specialised unit within cell which performs a function e.g. ribosome
82
Tissue
Group of cells working together to preform a shared function, often with similar structure
83
How lungs (alveoli) are adapted for gaseous exchange
- large surface area to volume ratio
- thin walls for short diffusion path
- large number in each lung (350 million per lung)
