Organisation Flashcards
1
Q
Define tissue
A
a group of cells working together with a similar structure and function
2
Q
Define organ
A
a group of tissues working together for a specific function. Eg the stomach
3
Q
Define organ systems
A
organs are grouped together to form organ systems which work together to form organisms
4
Q
Name the three main nutrients found in food
A
.Carbohydrates (eg starch)
.Protein
.Lipids
5
Q
Define digestion
A
the process by which large food molecules are broken down into small molecules by enzymes. The small molecules can then be absorbed into the bloodstream.
6
Q
Describe the pathway of food through the digestive system
A
Mouth — Oesophagus — Stomach — Small intestine —- Large intestine
7
Q
Function of the mouth in digestion
A
Digestion of food starts in the mouth. Teeth break down the food and mix it with the enzymes in saliva (produced by salivary glands)
8
Q
Function of the liver in digestion
A
Releases bile which helps speed up the digestion of lipids. Bile also neutralises the acid released from the stomach.
9
Q
Function of the gallbladder in digestion
A
Stores and concentrates bile
10
Q
Function of the stomach in digestion
What happens?
A
.In the stomach the enzymes begin the digestion of proteins (hydrochloric acid helps the enzymes to digest proteins)
.The churning action of the stomach muscles turns the food into a fluid (increasing SA for enzymes to digest)
11
Q
Function of the pancreas in digestion
A
This releases enzymes into the intestines which break down carbohydrates, protein and lipids in food.
12
Q
Function of the small intestine in digestion
A
Here, carbohydrates, proteins and lipids digest. The small food molecules produced are then absorbed into the blood.
13
Q
Function of the large intestine in digestion
A
Food which cannot be broken down - mainly fibre - passes into the large intestine. Water is absorbed into the blood.
14
Q
Define enzymes
A
a protein that acts as a biological catalyst, meaning it speeds up chemical reactions in the body without being used up in the process
15
Q
Describe the lock and key theory
A
The “lock and key” model explains enzyme action by suggesting that enzymes, acting as “locks,” have active sites with specific shapes that perfectly complement the shape of their specific substrates, or “keys,” allowing them to bind and catalyze reactions.
16
Q
What is the name of the enzyme that breaks down proteins?
A
Proteases
17
Q
Where can proteases be found?
A
Stomach
Pancreas
Small intestine
18
Q
What is produced when proteins are digested?
A
Amino acids which are then absorbed into the bloodstream
19
Q
What is the name of the enzyme that breaks down carbohydrates?
A
Carbohydrases
20
Q
An example of a carbohydrate is starch, what specific carbohydrase is it broken down by?
A
Amylase
21
Q
What is produced when carbohydrates are digested?
A
Simple sugars
22
Q
Where is the enzyme amylase found?
A
Saliva
Pancreatic fluid (pancreas)
Small intestine
23
Q
What does a lipid molecule consist of?
A
One molecule of glycerol attached to three molecules of fatty acids
24
Q
What is the name of the enzyme which digests lipids?
A
Lipase
25
When lipids are digested what do they produce?
Fatty acids and glycerol
26
Where can lipase be found?
Pancreatic fluid (Pancreas)
Small intestine
27
Where is bile made and where is it stored?
Made in the liver
Stored in the gall bladder
28
What does bile do? How?
Speeds up the digestion of lipids but is not an enzyme.
Bile emulsifies the lipid by converting large lipid droplets into smaller droplets, increasing the rate of lipid breakdown by lipase.
29
How does temperature affect enzyme activity? Why?
As we increase temperature, enzyme activity increases, this is because the enzyme and substrate are moving faster so there are more collisions per second between the substrate and active site. However, after the optimum temperature, then the activity of the enzyme rapidly decreases to zero. This is because the enzyme's active site is denatured meaning the enzyme can no longer catalyse the reaction.
30
How does pH affect enzyme activity? Why?
The enzyme has an optimum pH where the activity is maximum. But, if we make the pH more alkaline or acidic, then the activity drops to zero. That is because the active site denatures if the conditions are too alkaline or acidic. Additionally, each enzyme has a specific optimum pH.
31
How to prepare food sample into solution form?
1.Take food sample and grind this with distilled water using a mortar and pestle. We want to make paste
2. Transfer the paste to a beaker and add more distilled water. Stir so the chemicals in the food dissolve in the water
3. Filter the water to remove the suspended food particles
32
Test for starch
.Add a few drops of iodine solution the food/food solution
.If starch is present the iodine solution will turn blue black
.If there is no starch present then the iodine solution will stay orange
33
Hazards with the test for starch
.Iodine solution is an irritant
.Avoid contact with skin and eyes
.Wear safety goggles
34
Test for sugars
.Add Benedict's solution to the food solution
.Heat up in water bath
.Positive test ranges from the colours (green, yellow, orange, red) depending on the sugar concentration
.If no sugar is present, the solution remains blue
35
Hazards with the test for sugars
.Benedict's solution is an irritant
.Avoid contact with skin and eyes
.Wear safety goggles
36
Test for protein
.Add Biuret reagent to food solution and mix
.Positive test shows a purple or lilac colour
.If no protein is present, solution remains blue
37
Hazards for the test for protein
.Biuret reagent is an irritant
.Avoid contact with skin and eyes
.Wear safety goggles
38
Test for Lipids/Fats
.Add ethanol to the food/food solution
.Pour into second test tube containing distilled water
.If lipids are present a white cloudy emulsion forms
39
Hazards for the test for lipids
.Ethanol is flammable
.Avoid contact with skin and eyes
.Wear safety goggles
40
How is the small intestine adapted for absorbing the products of digestion?
.Very long
.The interior of the small intestine is covered with millions of villi
.Villi increase the SA for the absorption of molecules
.On the surface of villi, there are microvilli, further increasing the SA
.Villi have a very good blood supply so the bloodstream rapidly removes the products of digestion, increasing the concentration gradient
.Villi have a thin membrane (one cell thick) ensuring a short diffusion path
(All of these features mean that there is a rapid rate of diffusion)
41
Label the features on a heart diagram
.Use an image online
.Features should include:
Right and left atrium
Right and left ventricle
Valves
Vena cava
Pulmonary vein and artery
Aorta
42
Describe the pathway of blood
1) Deoxygenated blood enters the right atrium through the superior and inferior vena cava.
2) It then passes through a valve to the right ventricle
3) The pulmonary artery transports the deoxygenated blood to the lungs
4) Gaseous exchange occurs resulting in oxygenated blood
5) The pulmonary vein transports oxygenated blood from the lungs to the left atrium
6) It then passes through a valve to the left ventricle
7) Oxygenated blood is ejected from the heart and is transported to the body via the aorta
43
What is the difference between the left and right side of heart? Why?
The left side of the heart has a thick muscular wall then the right side. This is because the left ventricle pumps blood around the entire body, so it needs to provide a greater force. Whereas the right ventricle only pumps blood to the lungs.
44
What are the coronary arteris?
Spreading out into the heart, the coronary arteries provide oxygen to the muscle cells of the heart. The oxygen is used for respiration to provide the energy for contraction.
45
What is the natural pacemaker?
A group of specialised cells in the right atrium that generates electrical impulses that pass through the heart muscle and make the heart contract.
46
What is an artificial pacemaker?
A medical device that uses electrical impulses to regulate heart beats.
47
Function of the arteries
transport oxygenated blood (pulmonary artery is the only exception) away from the heart and throughout the body
48
Adaptations of the arteries
.Thick muscular walls, allowing them to withstand the very high pressure of blood
.Contains elastic fibres which enables arteries to expand and recoil during the heart's pumping cycle
49
Function of the veins
transport deoxygenated blood (pulmonary vein is the only exception) towards the heart
50
Adaptations of the veins
.Contains valves to stop backflow
.Thin walls because the pressure is low
51
Function of the capillaries
they are the smallest blood vessels which link the arteries to the veins
52
Adaptations of the capillaries
.Thin walls so diffusion pathway is short
53
Name the four main parts of the blood
Plasma
Red blood cells
White blood cells
Platelets
54
Main function of the plasma
primarily a transport medium, carrying various substances throughout the body
55
What does plasma transport?
Transports:
.Soluble digestion products from the small intestine to other organs
.Waste carbon dioxide produced by the cells is carried to the lungs
.Urea from your liver is carried to your kidneys where it is removed from your blood to form urine
56
Function of the red blood cells
transport oxygen from the lungs to the body cells
57
Name three adaptation of the red blood cells
.Contain the oxygen carrying molecule haemoglobin
.Do not have a nucleus meaning they have more room for haemoglobin
.Have a biconcave shape, increasing their surface area
58
Function of the white blood cells
They form part of the immune system and contain a nucleus which has DNA encoding the instructions that the white blood cells need to do their job.
59
Function of the platelets
They are tiny fragments of cells and their job is to help the blood clot
60
What is the percentage make up of each component of blood?
Plasma = 55%
Red blood cells = 45%
White blood cells and platelets = <1%
61
Uses of donated blood in medicine
.To replace blood lost during injury
.Some people are given platelets extracted from blood to help in clotting
.Proteins extracted from the blood can be useful for example antibodies
62
What are cardiovascular diseases?
They are non-communicable diseases of the heart and blood vessels
63
Examples of cardiovascular disease
.Coronary heart disease
.Heart valve disease
.Heart failure
64
What does coronary heart disease do?
.Layers of fatty acids build up inside the coronary arteries. This reduces the flow of blood through the coronary arteries, resulting in a lack of oxygen for the heart muscle.
65
What are the treatments for coronary heart disease and what do they do?
.Statins: drugs which reduce the level of cholesterol in the blood, slowing down the rate that fatty materials build up in the arteries
.Stent: a tube which can be inserted into the coronary artery to keep it open
66
Advantages and disadvantages of statins
Advantage
.They are an effective treatment, meaning they reduce the risk of heart disease
Disadvantage
.Have some side effects including liver problems
67
Advantages and disadvantages of stents
Advantage
.Blood can flow normally through the artery
Disadvantage
.It does not treat the underlying cause of the disease
68
Treatments for faulty heart valves
.Can be replaced with either a mechanical valve or a valve from an animal such as a pig
69
Advantage and Disadvantage of a mechanical valve
Advantage
.Last a lifetime
Disadvantage
.Increase the risk of blood clots meaning patients have to take anticlotting drugs
70
Advantage and Disadvantage of a valve from an animal
Advantage
Patient does not need to take drugs
Disadvantage
.They do not last long and may need to be replaced
71
Treatment options for heart failure
.Patients are given a donated heart or a donated heart and lungs
.Patients are given as an artificial heart as a temporary solution while waiting for a transplant
72
Pathway of air into the lungs
In through the mouth and nose
Enters the trachea
Trachea splits into two bronchi
Through the bronchioles
Air enters the alveoli where gaseous exchange takes place
73
How are alveoli adapted for gaseous exchange?
.The millions of alveoli means that the lungs have a huge SA
.Alveoli have very thin walls so the diffusion pathway is very short
.They have a very good blood supply, ensuring the concentration gradient is as steep as possible
74
Define cancer
a group of diseases characterized by uncontrolled cell growth and division, potentially leading to the formation of tumors
75
Define tumour
a lump or growth of abnormal cells that form when cells divide uncontrollably
76
Name the two types of tumours
Benign tumours
Malignant tumours
77
What are benign tumours?
Growths of abnormal cells which are found in one area and are usually contained within a membrane.
They do not invade other parts of the body; they stay in one place.
78
What are malignant tumours?
Malignant tumours consists of malignant cells which invade neighbouring tissues and move into the bloodstream. They are classed as a CANCER.
79
What are secondary tumours?
Once in the bloodstream the malignant cells spread to different parts of the body and they form new tumours. These are known as secondary tumours.
80
Name some cancers linked to genetics
.Certain types of breast cancer
.Prostate cancer
.Cancer of the large intestine
81
Name some cancers linked to lifestyle habits
Smoking: Lung cancer
Ultraviolet light: Skin cancer
Alcohol: Mouth and throat cancer
82
Define communicable disease
Diseases which can be spread from person to person (eg measles). They are spread by pathogens such as bacteria or viruses.
83
Define non-communicable disease
Diseases which can not be passed from person to person (eg coronary heart disease)
84
Risk factors for cardiovascular disease
.A diet high in fat and low in vegetable
.A diet high in salt
.Smoking
85
Label a cross section of a leaf
(Use an online diagram)
Key features it should include:
.Upper and lower epidermis
.Waxy cuticle
.Stomata
.Guard cells
.Palisade mesophyll
.Spongy mesophyll
.Air spaces
.Xylem and Phloem
.
86
What is the epidermis job?
To protect and cover the surface of the leaf. The upper epidermis is transparent, allowing light to pass through for photosynthesis below.
87
What is the waxy cuticle job?
Reduces the evaporation of water from the surface of the leaf, helping to prevent the leaf form drying out.
88
What is the stomata job?
control water loss and gas exchange by opening and closing.
89
What is the job of the guard cells?
control the opening and closing of the stomata
90
What is the job of the palisade mesophyll?
Contains palisade cells which are packed full of chloroplasts. Chloroplasts contain chlorophyll which absorbs light energy for photosynthesis.
91
What is the job of the spongy mesophyll?
Full of air spaces allowing for carbon dioxide to diffuse from the stomata, through the spongy mesophyll to the palisade cells. And vise versa for oxygen.
92
What is the job of the xylem?
Transports water from the roots to the stem and leaves. Some of the water is then used in photosynthesis. Also transports dissolved mineral ions including magnesium to make chlorophyll
93
What is the job of the phloem?
Transports dissolved sugars produced by photosynthesis from the leaves to the rest of the plant. The sugars can be used immediately (eg glucose in respiration).
94
Define translocation
the movement of sugars and other molecules through phloem tissue
95
What are meristem tissue?
Found at the growing tips in plants, meristem tissue contains stem cells which can differentiate into different types of plant tissue.
96
Define transpiration
the process where a plant loses water in the form of vapor through tiny pores called stomata on its leaves
97
Factors affecting the rate of transpiration
Temperature
Humidity
Windy conditions
Light intensity
98
How does each factor affect the rate of transpiration?
Increase in temperature, increase in transpiration
Increase in Humidity, decrease in transpiration
Windy conditions, increase in transpiration
Increase in light intensity, increase in transpiration
99
How does the stomata work?
The stomata contains guard cells which when light intensity is high, the guard cells swell and change shape; this causes the stomata to open.
Under hot conditions the plant closes its stomata to reduce water loss by transpiration, but means that the plant cannot photosynthesise.
