B2 Cell Organisation Flashcards
(149 cards)
1
Q
Define Cell.
A
Building block of life.
2
Q
Define Specialised Cell.
A
A cell adapted to carry out a specific function. The process by which cells become specialise is called differentiation.
3
Q
What is the job of the systems in large multicellular organisms?
A
Exchanging and transporting material.
4
Q
Define Tissue.
A
A group of similar cells that work together to carry out a particular function.
5
Q
Define Organ.
A
A group of tissues that work together to perform a certain function.
6
Q
Define Organ systems.
A
A group of organs working together to perform a particular function.
7
Q
What organs are in the digestive systems (in the order they come).
A
The digestive system begins in the mouth. It is followed by the salivary gland, pancreas, stomach, liver, small intestine, large intestine,rectum and anus.
8
Q
What is an enzyme?
A
An enzyme is a natural catalyst, they are large proteins made up of amino acids.
9
Q
What is a catalyst?
A
A catalyst is a substance which increases rate of reaction without being changed or used up during the reaction.
10
Q
What is the lock and key model?
A
The lock and key model means that enzymes only ever fit one type of substrate. Enzyme’s active sites are the right size and chemically accurate to fit a specific substrate.
11
Q
What does the graph of optimum temperature look like?
A
It gradually increases and then falls suddenly. The highest point is optimum temperature.
12
Q
What is meant by optimum temperature?
A
Optimum temperature is the best temperature for enzyme activity and thus increases rate of reaction.
13
Q
What is meant by optimum pH?
A
Optimum pH is the best acidity for enzyme activity and thus increases rate of reaction.
14
Q
What does the graph of optimum pH look like?
A
It gradually increases and then falls gradually. The highest point is optimum pH.
15
Q
How do you calculate rate of reaction?
A
Rate = 100/time
16
Q
How do you test for starch?
A
Iodine - Blue-black
You drop a few drops of iodine on the food, if it turns black-blue, it contains starch, otherwise, there is no starch.
17
Q
How do you test for sugar?
A
Benedict’s -Orangey red
Add equal quantities of water and Benedict’s solution to the food sample in the test tube, place it in a tub of 95 degree centigrade water bath. If the liquid turns cloudy orange or brick red starch is present.
18
Q
How do you test for protein?
A
Biurets - Purple
Place the food sample into a test tube, add water to the tube and stir to mix, add an equal volume of potassium hydroxide solution to the tube and stir, then add two drops of copper sulfate solution and stir for two minutes.
Proteins are detected using Biuret reagent . This turns a mauve or purple colour when mixed with protein.
19
Q
How do you test for fats?
A
Ethanol (Sudan III) - Cloudy
Place the food sample into a test tube and add ethanol and an equal volume of distilled water to the tube, cover and shake the tube vigorously. Allow the contents to settle. A milky-whiteemulsion forms if the test substance contains lipids.
20
Q
What does it mean if an enzyme i denatured?
A
This is when (due to incorrect pH, temperature) the active site on the enzyme changes becoming a wrong fit.
21
Q
What enzyme breaks down starch and into what product?
A
Amylase breaks down starch, it breaks it down, first into maltose and then glucose and other sugars.
22
Q
Amylase breaks down starch, where is it produced?
A
Amylase is produced in the salivary glands, pancreas and small intestine.
23
Q
What enzyme breaks down protein and into what product?
A
Protease breaks down proteins into amino acids.
24
Q
Protease breaks down proteins, where is it produced and what is the product of this reaction?
A
Protese is produces in the stomach (called pepsin), pancreas (called trypsin) and the small intestine (called peptidase).into amino acids.
25
What enzyme breaks down lipids and into what product?
Lipase breaks down lipids into glycerol and fatty acids.
26
What is the job of bile?
Bile neutralises acids leaving the stomach and emulsifies fat (breaks fat into smaller pieces with a larger surface area so it digests faster).
27
What is the job of the salivary glands?
Salivary glands produce salivary amylase which breaks down starch in the mouth.
28
What is the job of the gullet or oesophagus?
Transporting food for digestion and mechanical breaking down of food through muscular contractions.
29
What is the job of the mouth?
The mouth is where salivary amylase is released into the mouth to break down protein and where technical digestion of all food occurs through biting.
30
What is the job of the stomach?
As well as churning food, the stomach is also responsible for breaking down protein using the protease, pepsin. It also produces hydrochloric acid to kill bacteria and to ensure the correct pH for pepsin to work..
31
What is the job of the liver?
The liver produces bile. Bile neutralises stomach acids and emulsifies fat.
32
What is the job of the gall bladder?
The gall bladder is where bile is stored and then releases it into the small intestine.
33
What is the job of the pancreas?
The pancreas produce protease, amylase and lipase enzymes. It releases these into the small intestine.
34
What is the job of the Large Intestine?
Where excess water from food is absorbed.
35
What is the job of the Small Intestine?
Produces digestive enzymes and absorbs digested food into the blood stream.
36
What is the job of the Rectum?
Where faeces is stored before being excreted by the anus.
37
What is the thorax?
Upper part of your body
38
Describe which organs air goes through before gas exchange
| pathway of air
```
Nasal cavity/ Mouth
Trachea
Bronchus
Bronchiole
Alveoli
```
39
What protects the lungs?
Pleural membranes
| Ribs
40
What is the job of intercostal muscles?
To assist in inhalation by moving the ribs upwards and outwards to increase the chest cavity.
41
What is the job of the diaphragm?
To assist in inhalation by pulling the bottom of the lungs down to increase the chest cavity
42
How are alveoli specialised to do their jobs?
- Large Surface Area
- Many of them
- Good Blood Supply
- Only 1 cell thick
43
What occurs in the alveoli?
Gas exchange.
44
Describe the process of gas exchange during inhalation.
Oxygen enters the alveoli during inhalation,
Blood entering the network of capillaries leading up to the alveoli are deoxygenated,
Oxygen diffuse across the walls of the alveoli and capillary from an area of high concentration to an area of low concentration to be used in respiration.
45
Describe the process of gas exchange during exhalation.
Blood entering the network of capillaries leading up to the alveoli carry waste products such as carbon dioxide,
There is little or no carbon dioxide in the lungs,
Carbon dioxide diffuse across the walls of the capillaries and alveoli from an area of high concentration to an area of low concentration to be excreted.
46
What are the four elements of blood?
- Red Blood Cells
- White Blood Cells
- Platelets
- Plasma
47
What is the function of red blood cells?
Carry oxygen
48
What allows red blood cells to carry oxygen?
Oxygen connects to haemoglobin to create oxyhemoglobin.
49
What is the function of white blood cells?
To fight infections
50
What is the function of platelets?
To create blood clots
51
What is the function of plasma?
To carry waste products
52
Why is the circulatory system called a double circulatory system?
It consists of two full circulations
| See Figure 3
53
Starting in as deoxygenated and entering the heart, describe the pathway of blood
Deoxygenated blood enters through the vena cava and into the right atrium
At the first pump a valve opens and allows it into the right ventricle
On the second pump it is forced out of the heart through the pulmonary artery
This then reaches the lungs where it is oxygenated
Oxygenated blood then returns to the heart through the pulmonary vein and into the left atrium
At the first pump a valve opens and allows it into the left ventricle
On the second pump it is forced out of the heart through the aorta, this takes it to the rest of the body
Blood returns to the heart deoxygenated
(See Figure 4)
54
What causes the heart to pump twice?
There are 4 valves, in the first pump to open and in the second the other two do
55
Describe the function of valves
They prevent blood travelling backwards in the system
56
What controls the speed of heart beats?
A pacemaker
57
Describe how a pacemaker works
It produces a small electric impulse which spreads around the muscle causing it to contract
58
Describe a pacemaker (physically)
A small group of cells in the wall of the right atrium
59
Describe a solution for when a patients heartbeats are irregular
Artificial pacemaker
60
What is the function of the arteries?
Take blood away from the heart
61
What is the function of veins?
Take blood to the heart
62
What is the function of capillaries?
Take blood deep into muscle tissue and material exchange within these tissues
63
What makes arteries good for their function?
Thick outer wall
Elastic muscle wall to deal with high pressure
(See Figure 5)
64
What pressure is the blood carried by arteries?
Very High
65
What makes veins good for their function?
Very large lumen
Valves to deal with lack of pressure
(See Figure 5)
66
What pressure is the blood carried by veins?
Very Low
67
What makes capillaries good for their function?
Only 1 cell thick
Permeable membrane
Very small (can get everywhere)
(See Figure 5)
68
What is a lumen?
The hole in the middle of a blood vessel that blood travels through
(See Figure 5)
69
Define permeable
Substances can pass through
70
How many red blood cells fit though a capillary at any 1 time?
1
71
How are red blood cells specialised for their function?
Biconcave disc shape ( large surface area)
No Nucleus (more space)
Haemoglobin (red pigment which attaches to oxygen)
72
What is the process where white blood cells engulf pathogens?
Phagocytosis
73
What are the three ways white blood cells fight infection?
Phagocytosis
Antibodies
Antitoxins
74
How are white blood cells adapted for phagocytosis?
Can change shape
75
What are platelets made of?
Fragments of cell with no nucleus
76
Name 7 materials carried by plasma
```
Glucose
Amino Acids
Carbon Dioxide
Urea
Hormones
Proteins
Antibodies
Antitoxins
```
77
What is the cause of cardiovascular disease?
Fatty Build-up in the coronary arteries
78
What is a stent?
A tube inserted inside an artery so that fatty build-up is squashed, opening the artery and lowering the risks involved with coronary heart disease
(textbook page 37)
79
What are complications involved with stents operations?
Complications during operation:
- hear attack
Infection from the surgery
Thrombosis (when a blood clot form near the stent)
80
What are the two types of cholesterol?
HDL- good cholesterol
| LDL - bad cholesterol
81
What is cholesterol?
An essential lipid
82
What does too much LDL cholesterol cause?
Fatty deposits inside arteries
83
What do fatty deposits in the arteries cause?
Coronary Heart Disease
84
What is a statin?
A drug which reduces LDL cholesterol and increases HDL cholesterol and thus slows the forming of fatty deposits in the arteries
85
What is the function of statins?
Lower the risks of strokes, coronary heart disease and heart attack and
86
What are the disadvantages of statins?
Must be taken regularly
Not instant
Negative side effects
87
What could cause the prescription of a heart transplant?
Heart Failure
88
What is a donor organ?
The donated organ of a person who is recently deceased
89
What could be done if someone requires a heart transplant but no donor organs are currently available?
An artificial heart could be temporarily installed
90
What is an artificial heart?
A mechanical device which (temporarily) pumps blood around a persons body.
91
What are the advantages of an artificial heart?
They will not be rejected by the body as they are made of plastic/ metal and not detected as foreign
Can give the persons real heart time to heal
92
What are the disadvantages of an artificial heart?
Surgery can cause bleeding and infection
Can wear out - do not function as well as natural hearts
Drugs must be taken to thin the blood
93
What can cause heart valves to become weakened or damaged?
Heart attack
Infection
Age
94
What happens to damaged heart valves?
The tissue may to stiffen or won't open
| Or, it could become leaky allowing blood to flow in both directions
95
What are biological valves?
Valves made from other humans or mammals (cows or pigs)
96
What are mechanical valves?
Man-made valves
97
What can be a complication of replacing a valve?
Problems can be caused with blood clots
| Major surgery
98
What can we use to keep someone (temporarily) alive if they loose a lot of blood?
Artificial Blood
99
What is artificial blood made of?
Saline (salt solution) which can pump around the remaining red blood cells
100
What does artificial blood ideally give the patient time to do?
Produce new red blood cells
| If they cannot produce enough they may need a blood transfusion
101
Define Health
Complete state of social physical and mental wellbeing
102
Define communicable disease
A disease that can be spread from person to person or between animals and people
103
Define non-communicable disease
A disease that can not be spread from person to person or between animals and people
104
What does it mean in diseases interact?
If you have one disease and are infected by another, chances are your body can't deal with both at the same time and thus both worsen
105
What three factors affect your health?
Fitness
Social life
Mental stability
106
What is a risk factor?
Something which increases a persons chances of developing or contracting a disease
107
How can lifestyle be a risk factor to disease?
The amount of exercise they do
What they eat
How much sleep they get
108
How can the environment be a risk factor to disease?
Air pollution
| Sound pollution
109
How can substances that get into the body be a risk factor to disease?
(lead or asbestos)
These could be physically damaging
Could be toxic
110
What does it mean if a risk factor is a direct cause for a disease?
That this risk factor is the main (or only) reason that this disease has been contracted
The risk factor has caused the disease to occur
111
What are the socioeconomic disadvantages of non-communicable disease?
They tend to be very dangerous
They tend to be very long
Treatment tends to be very expensive
112
What are tumours?
Uncontrolled cell division
113
What are the two types of tumour?
Benign
| Malignant
114
Describe Benign tumors
Grow until they have more room
Stay in one place and are thus not cancerous
Usually not dangerous
115
Describe Malignant tumours
Cells break up and travel through the blood stream to neighbouring healthy tissue
Dangerous and can be fatal
These are cancers
116
What is a risk factor for lung cancer?
Smoking
117
What is a risk factor for bowel, liver or kidney cancer?
Obesity
118
What is a risk factor for skin cancer?
UV Exposure
119
What is a risk factor for liver cancer?
Viral Infections
| such as hepatitis B/C
120
What are genetic risk factors?
When you are more likely to contract a disease because you have inherited faulty genes
121
What is the function of epidermal tissue?
Acts as a barrier defence against pathogens
| in both animals and plants
122
What is the function of the palisade mesophyll tissue?
Contains many chloroplasts and is where photosynthesis occurs
123
What is the function of the spongy mesophyll tissue?
Allows gasses to diffuse up to the palisade tissue or down to the stomata
124
What is the function of stomata?
Small pores which allow gasses and water in or out by opening or closing
125
What is the function of guard cells?
Control the stomata
126
What is the function of waxy cuticle?
Reduces water loss through evaporation
127
Where can meristem tissue be found in a plant?
Growing tips of shoots and roots
128
Describe the cross section of a leaf?
The top layer is epidermal tissue with a waxy cuticle
The next layer is the palisade mesophyll tissue
Then there is the spongy mesophyll tissue
Finally there is another layer of epidermal tissue with stomata and guard cells
(See Figure 6)
129
How is the upper epidermis specialised for photosynthesis?
It is transparent so that light can pass though
130
How is the lower epidermis specialised for photosynthesis?
Contains stomata and guard cells
131
How is the stomata specialised for photosynthesis?
They have guard cells which
- allow them to open to take in reactants and let out waste products
- allow them to close to prevent water loss
132
How is the spongy mesophyll specialised for photosynthesis?
It has air spaces which means that gasses have shorter diffusion paths
133
How is the palisade mesophyll specialised for photosynthesis?
It contains many chloroplasts (where photosynthesis occurs)
134
Describe the phloem
Made of columns of elongated living cells with small pores to allow cell sap to flow through
135
Describe the xylem
Made of dead cells joined end to end with no end walls between them and a hole down the middle
136
What is the name of the material which strengthens the xylem?
Lignin
137
Describe the function of a xylem
Transport water and mineral ions from the roots to the leaves
138
Describe the function of a phloem
Transport food substances (many dissolved sugars) made in the leaves to the rest of the plant
139
What is translocation?
The process by which the phloem transports food substances around the plant
140
What is transpiration?
The movement of water from the roots, through the xylem and out through the leaves
141
What causes transpiration?
Evaporation and diffusion
142
Describe the process of transpiration
Water evaporates through the leaves
A shortage of water is created in the leaves
Water is drawn up through the rest of the plant
The roots have to draw more water
143
What four factors affect rate of transpiration?
Light Intensity
Temperature
Air Flow
Humidity
144
What does more humidity mean for transpiration?
Slower rate
145
What does greater light intensity mean for transpiration?
Faster rate
146
What does greater temperature mean for transpiration?
Faster rate
147
What does better air flow mean for transpiration?
Faster rate
148
What happens to guard cells when there is a lot of water in a cell?
They go turgid and plump
149
What happens to guard cells when there is little water in a cell?
They go flaccid
