Biology Topic 2 - Organisation Flashcards
1
Q
What is a tissue?
A
Group of cells with a similar structure and function
2
Q
Whats an organ?
A
Group of tissues working together for a specific function
3
Q
Whats an organ system?
A
Organs which work together to form organisms
4
Q
Example of a tissue
A
Muscle cells work together to make muscle tissue
5
Q
Example of an organ?
A
The stomach contains stomach tissue and glandular tissue which release enzymes
6
Q
Example of organ systems
A
Digestive systems
7
Q
What nutrients do foods contain?
A
Carbohydrates, protein and lipids
8
Q
What must occur so nutrients to be absorbed into the blood stream
A
Due to them being large molecules, they must be digested
9
Q
What happens during digestion, for large food molecules to be broken down
A
During digestion, large food molecules are broken down by enzymes so they can be absorbed into the bloodstream
10
Q
Whats the mouth?
A
Food is chewed in the mouth, which enzymes in the saliva begin to digest the starch into smaller sugar molecules
11
Q
Where does the food go after the mouth?
A
Goes down the oesophagus
12
Q
Where does the food go after the oesophagus
A
Goes into the stomach.
13
Q
What occurs in the stomach?
A
Enzymes begin the digestion of proteins.
Also, contains hydrochloric acid which helps the enzymes digest proteins. This occurs for several hours, and the stomach churning action of the stomach muscles turns the food into a fluid increasing the surface area for enzymes to digest
14
Q
Where does the fluid go after the stomach?
A
Goes into the small intestine
15
Q
Where are the chemicals realeased from in the small intestine?
A
Pancreas and liver
16
Q
What does the pancreas do?
A
Produce digestive enzymes
17
Q
What does the liver do?
A
Releases bile which helps to speed up the digestion of lipids. Bile also neutralises the acid released from the stomach
18
Q
What do the walls of the small intestine do?
A
Release enzymes to continue the digestion of protein and lipids
19
Q
What occurs in the small intestine?
A
The small food molecules produced by digestion are absorbed into the blood stream either by diffusion or active transport
20
Q
Where does the fluid go after the small intestine?
A
Makes its way to the large intestine where all water is absorbed into the blood stream
21
Q
Whats after the large intestine
A
Finally all feaces are released from the body
22
Q
What are the products of digestion used by the body for?
A
Build new carbohydrates, lipids and proteins
Some of the glucose is used for respiration
23
Q
What do enzymes do?
A
Catalyse chemical reactions
24
Q
What are enzymes?
A
Large protein molecules which have a groove on their surface called the active site
25
What does the active site bind to?
A substrate
26
Whats the lock and key theory?
The shape of an activate site is structured to fit a specific substrate
27
What enzymes are protein broken down by?
Proteases
28
Where are proteases found?
The stomach
Pancreas
Small intestine
29
What are the structure of protein?
Long chains of amino acids
30
What does protease do to proteins?
Converts the protein back to the individual amino acids, which are then absorbed into the bloodstream
This is then absorbed by body cells and joined in different orders to make human proteins
31
Structure of starch molecules
Chain of glucose molecules
32
What enzyme are starch broken down by?
Carbohydrases, in specific amalyse
33
What is produced when carbohydrates like starch are digested?
Simple sugars/Glucose
34
Where is amalyse found?
Saliva
Pancreas
35
Structure of a lipid molecule?
Molecule of glycerol attached to three fatty acid molecules
36
What enzyme are lipids digested by?
Lipase
37
Whats produced when lipids are digested?
Glycerol and fatty acids
38
Where is lipase found?
Pancreas
Small intestine
39
Where is bile made?
Liver and stored in gall bladder
40
What does bile do?
Help speed up the digestion of lipids but is not an enzyme
41
What does bile do to lipids?
Bile emulsifies the lipid into small droplet molecules
42
Advantages of bile emulsifying lipids?
Massively increases surface area of the lipid droplets which increases the rate of reaction by lipase enzyme
43
How does bile neutralise stomach acids?
Bile is an alkaline and neutralises hydrochloric acid in the stomach, creating better conditions for enzymes in the small intestine to digest food efficiently
44
What happens if we increase the temperature of an enzyme
The rate of reaction of the enzyme increases
45
Why does increasing the temperature, cause a faster rate of reaction
The enzyme and substrate are moving with more kinetic energy and are moving faster so there are more collisions per second between the substrate and active site
46
Whats the optimum temperature?
Certain temperature which the enzyme is working at the fastest possible rate and the maximum frequency of successful collisions between the subtrate and the active site
47
Whats the optimum temperature for most human enzymes
37°C
48
What happens if an enzymes temperature is past its optimum
The activity of the enzyme rapidly decreases to zero and becomes denatured
49
What occurs if an enzymes temperature is past its optimum?
The activity of the enzyme rapidly decreases to zero and the active site becomes denatured
50
Why does an enzyme become denatured as its temperature is past optimum?
The enzyme molecule vibrates and the shape of the active site changes and the substrate cant fit perfectly into the active site
51
What happens if the PH of an enzyme is less or more than optimum?
If the pH is too acidic or too alkaline then the activity drops to zero due to the active site becoming denatured
52
Example of an enzymes which works best at alkaline and acidic pH levels?
Acidic: Protease enzyme in the stomach
Alkaline: Enzyme release from the pancreas into the small intestine
53
How has the small intestine been adapted?
.Has a length of around 5m which provides a very large surface area for absorption of the products of digestion
.Contains millions of villi which increase the absorption of molecules
54
How have villis been adapted?
On the surface has a microvilli which increase the surface area further
Has very good blood supply so the bloodstream rapdily removes products of digestion and increase concentration gradiant
Thin membrane for short diffusion path
55
What occurs if a molecule cant be absorbed by diffusion?
Are absorbed by active transport
56
Circulatory system of a fish
Single circulatory system
Doxygenated blood is pumped from the heart to the gills which become oxygenated
Gills sends oxygenated blood back to the organs where the oxygen diffuses out od the blood and into the body cell
The blood now returns to the heart
57
What is the disadvantage of single circulatory systems?
The blood loses a lot of pressures as it passes through the gills. This means it delivers the oxygenated blood slowly and cant deliver a lot of oxygen
58
Benefits of the double circulatory system?
The blood passes to the heart twice and the oxygen can be transferred rapidly
59
Process of the double circulatory system?
Deoxygenated blood Is pumped into the right atrium then right ventricle to be pumped to the lung for gas exchange
Oxygenated blood flows into the left atrium then the left ventricle which pumps oxygenated blood around the body
60
Structure of the heart
Muscular walls to provide a strong heartbeat
Muscular wall is thicker on the left ventricle because blood needs to be pumped around the whole body rather than just to the lung like the right ventricle
4 chambers which seperate oxygenated and deoxygenated blood
Valves to make sure blood doesn't flow backwards
coronary artery cover heart to provide own oxygenated blood supply
61
Process of the heart pumping blood around the whole body
Blood flows into the right atrium through the vena cava, and left atrium through the pulmonary vein
Atria contract forcing blood into ventricles
Ventricles contract pushing blood in the right ventricle into the pulmonary artery to be sent to the lungs, and the left ventricle into the aorta to go around the body
As this happens the valves close to not allow any backflow
62
Natural resting heart rate?
70 BPM
63
What is the heart rate controlled by?
Group of cells found in the right atrium which act as a peacemaker.
64
How does the peacemaker control the heart rate?
Provide stimulation, through small electrical impulses which pass as a wave across the heart muscle causing it to contract
65
What happens without a peacemaker?
Heart would not pump fast enough to deliver enough oxygen around the body
66
What can be used if the hearts peacemaker doesn't function properly?
Artificial peacemaker
67
What does an artificial peacemaker do?
Electrical device which produces a signal so the heart beat at normal speed
68
What are the three blood vessels?
Arteries, Veins and capillaries
69
What do arteries do?
Carry blood away from the heart
70
How have arteries been adapted to their job?
Layers of muscles make them strong
Elastic fibre allow them to stretch which help vessels withstand high pressure created by pumping of the heart
71
What do Veins do?
Carry blood towards the heart
72
What's a lumen?
The actual tube which blood flows in
73
How have veins been adapted to its job?
Has a wide lumen to allow low pressure blood to flow through
Have valves to not allow any blood to go in the wrong direction
74
What are capillaries
Allow blood to flow very close to the cells to enable substances to flow between them
75
How have capillaries been adapted?
One cell thick walls to create short diffusion pathway
Permeable walls so substances can move across them
76
How to calculate rate of blood flow?
Volume of blood/Number of minutes
77
What's the thorax?
Area of body between the neck and abdomen
78
Where are lungs found?
In the lorax and are protected by your ribcage
79
What is the gas exchange system of the lungs made up of?
Trachea ( The windpipe, air moves up here)
Intercostal muscle (Contract and relax to ventilate lungs)
Bronchi ( Air from trachea move into these, lead to each lung)
Bronchioles (Bronchi split into these and air moves into)
Alveoli (Tiny air sacs for gas exchange where bronchioles lead to)
Diaphragm (Separates lungs from digestive organs, moves down causing inhalation)
80
What occurs in the ventilation phase?
Ribcage moves up and down, diaphragm moves down causing volume to increase
Increased volume = less pressure
Air drawn into chest as air move form area of high pressure to low pressure
Opposite happens when exhaling
81
What occurs in the gas exchange phase?
upon inhalation, alveoli fills with oxygen
Blood in capillaries surrounding alveoli is deoxygenated (Came from pulmonary vein). Has a lot of co2 from product of respiration
Oxygen diffuses down concentration gradient into capillary bloodstream
Co2 diffuses down concentration gradient from blood to alveoli
82
How have alveoli been adapted?
Very small and arranged in clusters increasing the surface area for diffusion
Capillaries provide large blood supply maintaining concentration gradient
Walls of alveoli very thin meaning short diffusion pathway
83
How to calculate breathing rate?
Number of breaths/Number of minutes
84
What is blood made of?
Plasma, Red blood cells, White blood cells and Platelets
85
What is a plasma?
Liquid which carries the components in the blood: Red and white blood cells, platelets, glucose, amino acids, co2, urea hormones, proteins, antibodies and antitoxins
86
What is a red blood cell?
Carry oxygen molecules from the lungs to all the body
87
How have red blood cells been adapted?
Bioconcave disc shape provides large surface area
No nucleus to carry more oxygen
Red pigment haemoglobin which binds to oxygen to form, oxyhaemoglobin
88
What are white blood cells?
Part of the immune system which is the body's defense against pathogens. Contain nucleus
89
What are pathogens?
Microorganisms that can produce disease
90
What are the different type of white blood cells.
1. One that produces antibodies
2. Ones that engulf and digest pathogens
3. Those that produces antitoxins to neutralise toxins produced by microorganisms
91
What do platelets do and the structure
Help the blood clot form on the wound
Small fragments of cells, contain no nucleus
92
How do platelets cover a wound?
Clot dries and hardens to form a scab, which allows new cells to grow underneath while preventing microorganisms to enter
93
What would happen if there is no platelets
Cuts would result in excessive bleeding and bruising
94
Whats coronary heart disease?
When coronary arteries are blocked with build up of fatty materials
95
What are the treatments to coronary heart disease?
Stents
Statins
96
What can coronary heart diseases lead to?
Less blood to the heart, reducing oxygen supply. May lead to heart attacks
97
What are stents and what do they do?
Metal mesh tubes inserted in arteries to keep them open
98
Advantages of Stents to prevent coronary heart disease?
Effective in lowering risk of a heart attack
Recovery time of surgery is quick
99
Disadvantages of stents to prevent coronary heart disease?
Risk of heart attack during procedure, or that infection following it
Chance that blood clots can form near stent
100
What are antibodies?
Clump of proteins to not allow any microorganisms entering
101
What are blood clots which form near the stent called?
Thrombosis
102
What are statins?
Drugs that decrease levels of LDL (The bad cholesterol which leads to coronary heart disease)
103
Advantage of statins
Reduce risk of strokes, coronary heart disease and heart attacks
Increase level of HDL
104
Disadvantages of statins?
Need to be taken continuously which may be an inconvenience
Can produce side effects
May not have immediate effect as it only slows down rate
105
What are consequences of faulty valves?
When a heart valve becomes stiff so cannot open or it is damaged so it leaks the blood goes in the wrong direction meaning the heart does not work as efficient
106
What are solutions of faulty valves?
Replacing with biological/mechanical valves
107
Advantages and disadvantages of using mechanical valves?
Advantages : Last for a long time
Disadvantages: Constant medication is needed to stop blood clotting around valve
107
Advantages and disadvantages of using biological valves?
Advantages : Works very well
Disadvantage: Only last 12-15 years
108
Advantages of artificial heart transplant?
Advantages: Less likely to be rejected by the immune system - metal and plastic are not seen as foreign
108
Methods to cure heart failure?
Heart transplant
Artificial Heart
108
Advantages and disadvantages of heart transplant?
Advantages: Heart transplant patients live longer
Disadvantage: Need to wait for a donor that recently have died. May be rejected by patient body
109
Disadvantages of artificial heart transplant?
Disadvantages:
Surgery temporarily leaves body open exposed to infections
Mechanical part could wear out and motor will fail
Blood clots can form and lead to stroke
109
How to prevent possible risks of artificial heart?
Drugs are taken to thin patients blood to affect individual bleeding if they are hurt
110
What is artificial blood?
A salt solution which can keep people alive if they lose 2/3 of their blood cells
110
How can extreme blood loss be treated?
By giving artificial blood
111
Advantages and disadvantages of using artificial blood
Advantage: Patient has more time to produce new cells
Disadvantage: Can only be used for a short period of time and blood transfusion would need to be used
112
What two categories can diseases fall into?
Communicable and Non-communicable diseases
112
What is health?
State of physical, mental and social well being
112
Factors which can cause ill health?
Diet, Stress, disease
112
What are communicable diseases?
These are infectious diseases caused by pathogens which can be passed from one another
113
Examples of diseases influencing eachother
A poor immune system, can cause them to become more likely to become infected with a communicable disease as the body cant fight it off
Someone who's disabled and is unable to carry out tasks can lead them to depression
114
What are non-communicable diseases?
Diseases which cannot be passed on from person to person
115
How can diet affect health?
Eating too little or too much food, can prevent them having a good diet which can affect physical and mental health causing issues such as obesity and diabetes type 2
116
How does stress affect health?
Places strain on bodies and can cause heart disease, cancer and mental illness
117
How do scientists prove causation(correlation) between diseases?
Find casual mechanism and how one disease influence another
118
How can cardiovascular disease be caused?
Diet containing lots of LDL resulting in arteries becoming blocked
Smoking damages arteries walls
119
How can cardiovascular disease be prevented?
Exercise and having a healthy diet
119
How does obesity cause type 2 diabetes?
Fat molecules are released and increases blood sugar levels as it breaks into glycerol
120
How can alcohol cause liver and brain issues?
Causes fatty liver which lead to liver failure
Alcohol can damage nerve cells in the brain
120
What is a malignant tumours?
Tumour can grow and spread to other tissues
120
Lifestyle risk factors of cancer
Smoking (Lung, Mouth, Bowel, stomach and cervical cancer)
Obesity (Bowel, Liver and kidney cancer)
UV Light (Skin cancer)
Viral Infection (Liver cancer from hepatitis B and C
Genetic risk, certain genes
121
What is cancer?
Changes in cells which result in uncontrollable growth and division, forming a tumour
122
What are benign tumors?
Growth of cells contained into one place, usually within a membrane
122
Features of benign tumours?
Not cancerous
Grows until no more room
Does not invade other tissues
Causes pressure or damage to an organ
122
Features of malignant tumours?
Cancerous
Tumour may split, resulting in cells being carried in the bloodstream
Can travel and stay at other organs, causing secondary tumours
Cancer cells divide more rapidly, and have a longer life span
123
Where is the palisade mesophyll tissue found?
Underneath the epidermal tissue?
124
Where is epidermal tissue found?
Covers the whole plant
124
Feature of epidermal tissue?
Covered with waxy cuticles
125
Function of waxy cuticles?
Helps to reduce water loss by evaporation as the waxy cuticles prevent water getting out
126
Feature of the palisade mesophyll tissue?
Has lots of chloroplasts
127
Function of having lots of chloroplasts
Having lots of chloroplasts means photosynthesis can happen more rapidly
They are positioned at the top of the leaf to receive lots of light
128
Where is the spongy mesophyll tissue found?
Underneath the palisade mesophyll tissue
128
Features of the spongy mesophyll
Has lots of air spaces
128
Function of spongy mesophyll
To exchange gases and store sugars and amino acids generated in the pallidade layer
128
Where are xylems found?
Roots, stems and leaves
128
Features of xylems
Made of dead cells joined together creating a tube
Strengthened with a substance called lignin, but has some holes along called bordered pits
128
Function of the xylem and adaptations?
Allows movement of water and mineral ions from the roots to the stem and leaves where it evaporates and leaves the plant. This is called Transpiration stream
Lignin makes it strong and waterproof so water will not leave except at bordered pits allowing minerals to go specific places around the plant
129
Where is the phloem found?
Roots, stems and leaves
129
Features of the phloem
Elongated cells with holes in the cell wall (Sieve Plates)
Many organelles are removed so cell sap can move through
129
Function of the phloem?
Moves food substances that the plant has produced by photosynthesis to where they are needed. This is called translocation
130
Where is the meristematic tissue found?
Tips of shoots and roots
130
Features of the meristematic tissue?
Able to differentiate into different type of plant cells
131
Function of the meristematic tissue?
Allows plants to grow
131
What is a leaf and what does it contain?
Plant organ which has the following tissues : epidermis, palisade, spongy mesophyll, xylem, phloem and guard cells
132
What is transpiration in plants?
Loss of water/water vapour from leaves and stems of plants due to a consequence of gaseous exchange as the stomata is open
133
What are factors which affect transpiration?
Increase in temperature, Increase in relative humidity, Increase in air movement, Increase in light intensity
134
How does increasing temperature increase rate of transpiration
Molecules move faster meaning evaporation occurring faster therefore transpiration rate is faster
Rate of photosynthesis increasing, meaning more stomata are open for gas exchange
134
What occurs if there is a increase in the relative humidity of water vapour in the air?
There will be a lower concentration gradient between the water vapour inside and outside of the leaf, decreasing diffusion and decreasing rate of transpiration
135
What happens if there is an increased air movement?
Wind will take away water vapour around the plant, creating a steeper concentration gradient and leading to high rate of diffusion and higher rate of transpiration
136
What happens to the rate of transpiration if there is an increase in light intensity?
Increase in rate of photosynthesis, more stomata open meaning more water can evaporate
136
Features of guard cells?
They are kidney shaped
Have thin outer walls and thick inner walls
137
How to measure rate of transpiration?
Using a potometer. Place a plant in a tube of water and measure distance bubble travels
138
How have stomata adapted?
When lots of water is available the stomata opens to allow transpiration
Found at the bottom of a plant as the bottom has shade and is cooler to minimise loss of water
