Organisation Flashcards
What are cells
Cells are the basic building blocks of all living organisms
What is a tissue
A tissue is a grouo of cells with a similar structure and function
What are organs
Organs are aggregations of tissues performing specific functions
Explain the link between organs, organ systems and organisms
Organs are organised into organ systems, which work together to form organisms
What is differentiation
The process by which cells become specialised for a particular job is called differentiation
In mammals, examples of tissues include:
- Muscular tissue, contracts to move whatever it’s attached to
- Glandular tissue, makes and secretes chemicals like enzymes and hormones
- Epithelial tissue, covers some parts of the body
The stomach is made up of these tissues
Muscular tissue - moves stomach wall to churn food
- Glandular tissue- makes digestive juices to digest food
- Epithelial tissue, covers the outside and inside of the stomach
Whats an organ
A group of different tissues that work together to perform a certain function
What is an orgsn system
A group of organs working together to perform a particular function
How do you work out the rate of reaction
Rate = 1000/ time
What is the definition of an enzyme?
A catalyst is a substances which increases the speed of a reaction, without being changed or used up in the reaction.
Enzymes are biological
Catalysts
Explain the lock and key method
The substrate enters the enzyme where the enzyme catalyses one specific reaction so has a specific shape for only one type of substrate.
The enzyme is unchanged after the reaction but the substrate is made into smaller pieces
Active site?
Where the reaction takes place
How does temperature effect enzyme reaction
Temperature:
- a higher temperature increases the rate at first. But if it gets too hot, some of the bonds holding the enzyme together breal
- this changes the shape of thenenzyme’s active site, so the subtrate won’t fit any more. The enzyme is said to be DENATURED
- ALL enzymes have an OPTIMUM TEMP that they work best at
How does Ph affect the rate of enzyme action
-The pH also affects enzymes. If it’s too high or too low, the pH interferes with the bonds holding the enzyme together.
-This changes the shape of the active site and denatures the enzyme.
-All enzymes have an optimum pH that they work best at. It’s often neutral pH 7
but not always.
-e.g. pepsin is an enzyme used to break down proteins in the stomach. It works best at pH 2, which means it’s well-suited to the acidic conditions there.
What do carbohydrases convert carbohydrates into
Simple sugars
Amylase is an example of a carbohydrase and breaks down starch into
Maltose
Amylase is made in three places:
Salivary glands
Pancreas
Small intestine
Proteases conveet proteins into
Amino acids
Where are the three places proteins are made:
Stomach
Pancreas
Small intestine
Lipases converts lipids into
Goycerol and fatty acids
Lipases are made in two poaces:
Pancreas and small intestine
What are the products of digestion used to build
The products of digestion are used to build new carbohydrates, lipids and proteins. Some glucose is used in respiration.
Where is bile made
Liver
Where is bile stored
In the gall bladder
What is the role of bile
It is alkaline to neutralise hydrochloric acid from the stomach. It also emulsifies fat
to form small droplets which increases the surface area. The alkaline conditions and large surface area increase the rate of fat breakdown by lipase.
Enzymes used in digestive system are produced by specialised cells in
Glands and in the gut lining
Salivary glands role
These produce amylase enzyme in the saliva
Liver role?
Where bile is produced. Bile neutralises stomacj acid and emulsifies fats
What is the role of the stomach
- pummels the food with its muscular walls
- produces the protease enzyme, pepsin
- produces hydrochloric acid for two reasons:
- kill bacteria - give the right pH for the protease enzyme to work
What is the role of the pancrease
Produces protease, amylase and lipase enzymes. It releases these into the small intestine
What is the role of the small intestine
- produces protease, amylase and lipase enzymes to complete digestion
- also where the food
What is the role of the rectum
Where the faeces are stored before they bid you a fond farewell through the anus
What is the rooe of the large intestine
Where excess water is absorbed from the food
What is the role of the gall bladder
Where bile is stored, before it’s released into the small intestine
What is the thorax
The top part of your body
Whats the lower part of the body called
Diaphragm
What is the lungs protected by
Ribcage
Look at the diagram on page 33 to see where everything on the lungs is labelled
Alveoli are
Millions of little air sacs in the lungs surrounded by blood capillaries.
Explain how gas exchange occurs in the body
The blood passing next to the alveoli has just returned to the lungs from the rest of the body, so it contains lots of carbon dioxide and very little oxygen. Oxygen diffuses out of the alveolus (high concentration) into the blood (low concentration). Carbon dioxide diffuses out of the blood (high
concentration) into the alveolus (low concentration) to be breathed out.
When the blood reaches body cells oxygen is
released from the red blood cells (where there’s a high concentration) and diffuses into the body cells (where the concentration is low).
At the same time, carbon dioxide diffuses out of the body cells (where there’s a high concentration) into the blood (where there’s a low concentration). It’s then carried back to the lungs.
What is the hearts role
The heart is an organ that pumps blood around the body in a double circulatory system.
Explain what the right ventricle does in the double circulatory system
The right ventricle pumps deoxygenated blood to the lungs to take in oxygen. The blood then returns to the heart
Explain what the left ventricle does in the double circulatory system
The left ventricle pumps oxygenated blood around all the other organs of the body. The blood guves up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again
Where is the pulmonary artery, vena cave e.t.c
CGP 34
What do valves do in the heart
To make sure that blood flows in the right direction - they prevent it flowing backwards
Explain how boood is pumped around the heart
- Blood flows in the two atria (left and right atrium) from the vena cava and pulmonary vein
- The ATRIA contract, pushing the blood into the ventricles
- ventricles contract, forcing the blood into the pulmonary artery and aorta, and out of the heart
- blood then flows to organs through arteries, returns through veins.
- atria fill again and the whole cycle starts over.
How is the natural resting heart rate controlled
The natural resting heart rate is controlled by a group of cells located in the right atrium that act as a pacemaker.
The cells produce a electrical impulse which spreads to the surrounding muscle cells, causing them to contrsct
The body contains three different types of blood vessel:
• arteries - these carry the blood away from the heart
• veins - carries blood to the heart
• capillaries - these are involved in the exchange of materials at the tissue
Explain the characteristics in relation with their functions of ARTERIES
- the heart pumps blood out at high pressure so the artery walls are STRONG and ELASTIC
- walls are THICK compared to the size of the hole down the middle (the lumen)
- they contain THICK LAYERS of MUSCLE to make them STRONG, and ELACTIC FIBRES to allow them to stretch and spring baco
Explain the characteristics in relation to their functions of CAPILLARIES
- very TINY
- carry the blood really close to every cell in the body to exchange substances with them
- has PERMEABLE walls, so substances can DIFFUSE in and out.
- supplies FOOD and OXYGEN, takes away WASTE like CO2
- walls are ONE CELL THICK. Increases the rate of diffusion by DECREASING the distance over which it occurs
Explain the characteristics in relation to their functions of VEINS
- blood is at a LOWER PRESSURE in the veins so walls dont need to be as thick as artery walls
- have BIGGER LUMEN than arteries to help the blood flow despite the lower pressure.
- they also have valves to help keep the blood flowing in the right direction
RATE OF BLOOD FLOW =
VOLUME OF BLOOD / NUMBER OF MINUTES
Explain artificial pacemakers
Artificial pacemakers are electrical devices used to correct irregularities in the heart rate.
Explain the functions and adaptions of RED BLOOD CELLS
- red blood cells’s job is to carry oxygen from the lungs to all the body cells in the body,
- shape is a BIOCONCAVE DISC- gives large SURFACE AREA for absorbing oxygen.
- has no nucleus - more oxygen can be carried.
- contains a pigment called HAEMOGLOBIN
- in lungs, haemoglobin BINDS to OXYGEN to become OXYHAEMOGLOBIN.
- in body tissues, the reverse happens- oxyhaemoglobin splits up into haemoglobin and oxygen, to release oxygen to cells
Explain the functions and adaptions of WHITE BLOOD CELLS
- some change shape to globble up unwelcome microorganisms, in a process called PHAGOCYTOSIS.
- Others produce ANTIBIOTICS to fight microorganisms, as well as ANTITOXINS to neutralise any todins produced by the microorganisms.
- has a nuceus
EXPLAIN THE FUNCTIONS AND ADAPTIONS OF platelets
- they are small fragments of cells, have no nucleus
- they help the blood to clot at a wound - to stop all your blood pouring out and to stop microorganisms getting in
- lack of them can cause excessive bleedijg and bruising
Describe the function of plasma
It carries everything from white/red blood cells to urea and hormones
What is coronary heart disease?
When the coronary arteries that supply the blood to the muscle of the heart get blocked by layers of fatty material building up.
- causing arteries go become narrow, so boood flow is restricted and there’s a lack of oxygen to the heart - resulting in heart attack possibly
What are stents? Advantages /disadvantages
Tubes that are inserted inside arteries to keep the coronary arteries open.
- they are effective for a long time and recovery time after surgery is quick
- risk of heart attack during surgery and infection.
-also may develop blood clot (called thrombosis)
What are statins
Statins are widely used to reduce blood cholesterol levels which slows down the rate of fatty material deposit.
- too much LDL cholestrol causes fatty deposits to build up so statins reduce the amount of it.
Advantages/ dis of statins
Ads:
- reducing amount of LDL cholestrol in blood, statins reduce risk of strokes, coronary heart disease and heart attacks.
- statins increase amount of HDL cholestrol in bloodstream (beneficial =HdL)
- statins prevent other diseases
DIS:
- statins = long-term drug must be taken REGULARLY.
- can cuase negative side effects: headaches or kidney failure, liver damage.
- not instant effect. Takes time for their effect to kick in
In the case of heart failure a donor heart, or heart and lungs can be transplanted. Artificial hearts…
Artificial hearts are occasionally used to keep patients alive whilst waiting for a heart transplant, or to allow the heart to rest as an aid to recovery.
Ads and dis of artificial hearts…
ADS:
- less likely to be rejected by the body’s immune system than donor heart (as they are metals/plastics, so body doesn’t recognise them as ‘foreign’ and attack in the same aay as it does with living tissue.
Dis:
- surgery can lead to bleeding and infection
- doesn’t work as well, artificial heart may wear out or electrical motor may fail.
- blood doesn’t flow as smoothly through artificial hearts causing noood clots/strokes
In some people heart valves may become faulty, meaning….
Preventing the valve from opening fully, or the heart valve might develop a leak ( blood flows in both directions meaning blood dont ciculate properly)
Valves in ghe heart can be damaged or weakened by
heart attacks, infection or old age
Faulty heart valves can be replaced using
Biological valves (humans/other mammals) or mechanical valves (man-made)
Faulty heart valves surgery may cause
Blood clots
What is artificial blood
Its a blood substitute, which is used go replace the lost volume of blood. It may give patient enough time to produce new blood cells
Health is
the state of physical and mental well-being.
Communicable diseases are
Those that can spread from person to person or between animals and people.
Caused by bacteria,viruses,parasites and fungi.
Examples are measles and malaria
Non-communicable diseases are
those that cannot spread between people or between animals and people. Lasts for long time and get worse slowly. Examples = asthma, cancer.
Different types of disease may interact.
• Defects in the immune system mean that an individual is more likely to suffer from infectious diseases.
• Viruses living in cells can be the trigger for cancers.
• Immune reactions initially caused by a pathogen can trigger allergies such as skin rashes and asthma.
• Severe physical ill health can lead to depression and other mental illness.
Factors apart from disease that affect your health:
- whether or not you have a good, balanced diet that provides body sith everything it needs in right amounts, poor diet can affect your physical health and mental health.
- stress can cause health issues
- life situation (whether you have easy access to medicine to treat illness’
What are risk factors
Are things that are linked to an increase in likelihood that a person eill develop a certain disease during their lifetime
Risk factors for disease could be
- aspects of a person’s lifestyle
• substances in the person’s body or environment.
Lifestyle factors czn have different impacts locally, nationally and globally:
- in developed countries, non-communicable diseases more common as people have higher income and can buy high-fat food.
- nationally, people from deprived areas more likely to smoke, have poor diet and no exercise. Meaning incidence of cardiovascular disease, obesity and type 2 diabetes is higher in those areas.
- Locally, hour choices affect the local incidence of disease.
Some risk factors are able to directly cause a disease: for example
1)SMOKING has been proven to directly cause cardiovascular disease, lung disease and lung cancer. It damages the walls of arteries and the sells in the lining of the lungs.
2) It’s thought that OBESITY can directly cause Type 2 diabetes by making the body less sensitive or resistant to insulin, meaning that it struggles to control the concentration of glucose in the blood.
3) DRINKING too much alcohol has been shown to cause liver disease. Too much alcohol can affect brain function too. It can damape the nerve cells in the brain, causing the brain to lose volume.
4) Smoking when PREGNANT can cause lots of health problems for the unborn baby,
Drinking alcohol has similar effects.
5) CANCER can be directly caused by exposure to certain substances or radiation. Things that
cause cancer are known as carcinogens. lonisins radiation (e.g. from X-rays) is an example of a carcinogen.
Explain how non-communicable diseases can be costly
- human cost is obvious. You can die. Also, lower quality of life or shorter lifespan. Affects sufferers and their loved ones.
- financial costs- researching and treating is costly. Families have go adapt and may give up work of die, so family income will be reduced.
Benign tumours are
growths of abnormal cells which are contained in one area, usually within a membrane. They do not invade other parts of the body.
Malignant tumour cells are
cancers. They invade neighbouring tissues and spread to different parts of the body in the blood where they form secondary tumours.
Cancer survival rates have increased due to
Medical advances such as improved treatment, being able to diagnose cancer earlier and increased screening for the disease
Scientists have identified lots of lifestyle factors for various types of cancer. For exmaple:
1) Smoking - It’s a well known fat that amoking in linked to lung cancer, but research has also linked it to othet typeg of cancer too, including mouth, bowel, stomach and cervical canoer.
2) Obesity - Obesity has been linked to many different cancers, including bowel, liver
and kidney cancer. It’s the gecond,.biggest preventable cause of cancer after amoking.
3) UV exposure - People who are often exposed to UV radiation from the sun have an increased chance of developing skin cancers. They invade neighbouring tissues and spread to different parts of the body in the blood where they form secondary tumours. People who live in sunny climates and people who spend a lot of time outside are at higher risk of the disease, People who frequently use sun beds are also putting themselves at higher risk of developing skin cancer.
4) VIRAL INFECTION - Infection with some viruses has been shown to increage the chances of developing pertain type of cancer. For example, infection with hepatitis B and hepatitis C viruses can increase the risk of developing liver cancer. The likelihood of beooming infected with these viruses sometimes depends on lifestyle - e.g. they can be spread between people through unprotected sex or sharing needles.
Explain how risk fsctors can be associated with genetics
Sometimes you can inherit faultygenes that make you more susceptible to cancer
Plants are made of the following tissues:
- EPIDERMAL TISSUE- covers the whole plant
- PALISADE MESOPHYLL TISSUE- this is the part of the leaf where most photosynthesis happens
- SPONGY MESOPHYLL TISSUE- this is also in the lead, contains big air spaces to allow gases to diffuse in and out of cells
- XYLEM AND PHLOEM - they transport things like water, mineral ions and food around the plant.
- MERISTEM TISSUE- this is found at the growing tips of shoots and roots and is able to differentiate into lots of different tyoes of plant cell, allowing the plant to grow.
What are the functiojs of the structures of the tissue that make up the leaf:
- EPIDERMAL TISSUES are covered with waxy cuticle, which helps to reduce water loss by evaporation.
- UPPER EPIDERMIS = transparent so that light can pass through it to the palisade layer.
- Palisade layer= lots of chloroplast, near top of leaf to get most light
- ## XYLEM AND PHLOEM - delivers water and other nutrients to the entire leaf and take away the glucose produced by photosynthesis.
XYLEM TUBES TAKE WATER UP:
- made of dead cells joined end to end with no end walls between them and a hole doen the middle
- strengthened by a material called lignin
- they carry wyaer and mineral ions from thenroots to the stem and leaves
- movement of water from roots to xylem and out of the leaves is called TRANSPIRATION STREAM
Page 43 BOTTOM OF CGP
Transpiration rate is affected by:….
LIGHT INTESNTIY:
- brighter the light, the greater the transpiration rate
- Stomata begin to close as it gets dark as photosynthesis can’t happen in the dark, so they don’t need to be open to let CO2 in.
TEMPERATURE:
- the warmer it is, the faster transpiration happens.- when it’s warm the water particles have more energy to evaporate and diffuse out of the stomata.
AIR FLOW:
- the better the air flow around leaf, greater tanspiration rate.
- if air flow is poor, the wateer vapour just surrounds the lead and doesn’t move away.
-meaning there’s a high conc. of water particles outside the leaf as well as inside, so diffusion don’t happen as quick. If there’s good air flow, water vapour is swept away, maintaining a los conc. of water in the air outside the leaf. Diffusion happens quickly.
HUMIDITY:
- the drier the air around the leaf, the faster transpiration happens.
- if air is humid there’s a lot of wayer in it already, so there’s not much of a difference between the inside and the outside of the leaf
- Diffusion happens fastest if there’s a really high conc. in one place, and a really low concl in the other
Guard cells features/structures:
- have kidney shape which opens and closes the stomata in a leaf.
- thin outer walls and thickened inner walls make the opening and closing work.
- sensitive to light and close at night to save water without losing out on photosynthesis.
- found on underside of leaves more than the top. The lower surface is shaded and cooler- sp less watee is lost through the stomata than if they were on the upper surface.
The role of stomata and guard cells are
to control gas exchange and water loss.
When the plant has lots of water
The guard cells fill with if and go plump and turgid. Making the stomata open so gases can be exchanged for photosynthesis
When the plant is short of water,
The guard cells lose water and become flaccid, making the stomata close. This helps stop too much water vapour escaping.
