Friday, 17 February 2012

5.9 Fish Farming

5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality, control of intraspecific and interspecific predation, control of diseases, removal of waste products, quality and frequency of feeding and the use of selective breeding.



Fish farming:
1. Fish have low fat and high protein :)
2. Efficient at turning the nutrient into fish mass :)

Advantages: Fish farming will allows us to….
1. Control quality of water = clean
2. Control predators
3. Reduces pests
4. Reduce disease

By controlling the above we contribute to an increase in yield of fish

Where there is a high density of fish, then the possibility of transmission of disease.

Some fish farmers use Antibiotics that is a concern to human health.

The abundance of fish also makes pests common therefore some fish farmers have taken to using pesticides. Also a concern amongst human health

5.8 Fermenter

5.8 Interpret and label a diagram of an industrial fermenter and explain the need to provide suitable conditions in the fermenter, including aseptic precautions, nutrients, optimum temp and pH, oxygenation and agitation for the growth of microorganisms.



The reaction vessel in which fermentation occurs

Such a vessel is usually built of metal (copper/steel)



To maintain optimum temp conditions:
- In between the two Steel jackets is water. It allows us to cool down the reaction.
- Steam, sterilises the fermenter between fermentations.
- In a fermenter there is a heating plate (heater) to raise the temperate

...also includes:
- So fermentation can occur, nutrients are inserted. Food for the microorganisms
- Monitor temp: Temp probe. Tells whether to deploy the heater or cooling jacket
- Microorganisms (tap to add them)
- pH probe – to try to keep at optimum.
- Turning devise. To agitate the mixture, stopping it clumping, spreading microorganisms
- Way to drain of the product -→ Which will then go on to a process call downstream processing which involved purification.

The idea of the fermenter is to create a reaction centre in which you control the optimum growth conditions for the microorganisms. So its able to produce the product we are looking or.

5.7 Production of Yoghurt

5.7 understand the role of bacteria (Lactobacillus) in the production of yoghurt

Milk is pasteurized to kill and unwanted bacteria, cultures of Lactobacillus bacteria are then added and the mixture is maintained at 46 degrees centigrade. The bacteria feeds on the milk and grows, reeling lactic acid, which has a preservative effect. The acid pH causes the milk protein to coagulate.

5.5 Beer production

5.5 Understand the role of yeast in the production of beer



Beer is largely Ethanol (an alcohol molecule) which is produced from glucose.

Glucose --→ Ethanol + carbon dioxide (a form of anaerobic respiration)
- The microorganism that does this is Yeast which supply’s the enzymes

Ethanol is flavoured by plants such as Hops

Glucoses comes from starch
Starch ----(amylase ‘germination;)--→ Maltose ----(Maltose)---→ Glucose
The starch comes from things such as barley seeds, wheat seeds, and rice.

Yeast brings about the anaerobic respiration of glucose to ethanol and carbon dioxide

5.2b Biological control

5.4b understand the reasons for pest control and the advantages and disadvantages of using biological control with crop plants.



Biological control:

Introduced species

Advantages:
1. There are no toxic chemicals involved
2. Less impact on man/wildlife

Disadvantages:
1. Not 100% effective
2. Often difficult to control (introduced species will find alternative prey to feed on and not actual die out ones the pest has been removed.)
3. Difficult to match a predator to the prey

54a Pesticides

5.4a Understand the reasons for pest control and the advantages and disadvantages of using pesticides with crop plants.



Pesticides:
Large fields of crops that are all of the same type of crop = Monoculture
Monocultures are very susceptible to pests. They use the crop as their food source. Which reduces the productivity of farming. = Loss of food and financial impact on the farmer.

1. Use Pesticides.
Pesticides are chemicals, designed to kill the pest.

Advantages:
1. Chemicals so are easy to obtain
2. Easy to apply (simply spray on crop)
3. Very effective

Disadvantages:
1. Many are toxic – possible kill other plants and animals
2. Bio accumulation – Pesticides builds up in the food chain causing harm to the food source in the higher tropic levels (eg DDT)
3. Mutation in the pest often leads to resistance, so the pesticide must be applied in high concentrations – therefore more toxic.

5.3 Fertilisers

5.3 understand the used of fertilizer to increase crop Yield



Aim: To increase growth in plant

Growth is achieved by the application of fertilisers to the soil and these normally take the form of nitrates of phosphates (sometimes both)

These compounds go into the soil and into the root structure, then moved in the transpiration stream to the leaf and used in the leaf.



In leaf:
- Nitrates will form proteins
- Phosphates are involved in DNA and membrane structure

The fertilisers can be divided into two groups:

1. The organic fertilisers
- Produced from animal waste from farm (cow faeces) – through a process of decomposition and fermentation and forms a substance known as slurry. Slurry is supplied to the field giving them a supply of Nitrate and Phosphate to promote growth.

2. Artificial fertilisers
- Form of synthetically produced chemicals (i.e Potassium nitrate and Ammonium nitrate), which can be bought by the farmer and placed in a solution and applied to the farm. These will release the nitrates, which will promote growth.

5.2 Crop Yield

5.2 Understand the effects on crop yield of increases carbon dioxide and increased temperature in glasshouses.




Rate of photosynthesis -combination of co2 + water -----light/enzyme=me-→ glucose (starch – stored by plant) + o2

Increasing the concentration of co2 = substrate



The rate of photosynthesis will increase which will mean there will be a higher yield up to a certain point when we increase the co2 level.

Increase the temperature:


As we increase the temp there is an increase in the rate of reaction increasing the yield - until it hits a peak that is the optimum temperature.

The both an increase in the yield but both have limits

Increasing temp also
- Helps avoid frost damage
- Provides constant temperatures.

5.1 Glasshouses

5.1 describe how glasshouses and polythene tunnels can be used to increase the yield of certain crops



Glasshouses are sometimes know as greenhouses.
Constructed on a framework (like a house) where all surfaces are made of glass, which allows light to penetrate though to the interior.

Polythene tunnels are a framework with polythene over the surface that allows light to penetrate through. Associated with market gardening, also used in less developed countries since its cheaper with glass and easier adjustable.

How does the glasshouse work:
- Solar radiation – initial source of energy in the form of light.
- Light is able to penetrate though the glass into the interior surfaces.
- The light is absorbed by surfaces inside the glasshouse (soil, wooden surfaces, plants)
- The surfaces will readmit the energy as heat.
- The heat warms the air – raising its average kinetic energy = temp increase
- The warm air is trapped, sending it back down to bottom of glasshouse
- protects from stop winds and heavy rain

Warm air in glasshouse ---→ increase in crop yield

- High temps in the class house lead to closer/optimum temp for enzyme reactions (photosynthesis)
- Provides constant tem throughout year. Which = constant production.
- Prevention of loss of water vapour – crops don’t dry out because they have a constant supply of water vapour
- Avoid frost damage – particularly to seedlings in springtime.
- Glasshouses are often warmed by the burning of fossil fuels, which leads to an increase in the CO2 levels in the glasshouse. This increases the concentration of the substrate for photosynthesis causing more product and growth. Inefficient burning of fossil fuel ethane, this gas stimulates fruit ripening(tomato)

Tuesday, 7 February 2012

2.89 Hormones

2.89 understand the sources, roles and effects of the following hormones: ADH, adrenaline, insulin, testosterone, progesterone and oestrogen.


HORMONE----- ENDOCRINE GLAND------TARGET TISSUE--------EFFECT
Oestrogen ------Ovary/Follicle------------Uterus-----------Increase thickness
Testosterone----Testis--------------------Testis------------Matures sperm
Progesterone---Corpus Luteum --------Uterus---------Maintains Thickness
Adrenaline-------Kidney--------------- Heard/blood -----Increase Heart Rate
Insulin-------------Pancreas---------------Liver------------Glucose → Glycogen which is stored as Liver Glucose
Glucagon --------Pancreas -------------Liver -----------Opposite of Insulin

Monday, 6 February 2012

2.87 near and distant objects

2.87 understand the function of the eye in focusing near and distant objects, and in responding to changes in light intensity.

Rays of light from distant objects are almost parallel when they enter the eye. They require less bending and the cornea can manage most of it without help from the lens. Muscles in the ciliary body relax and the lens is pulled into a thinner shape by the suspensory ligaments. This provides the correct focusing power.

Rays of light from near object are already diverging when they enter the eye. They need much more powerful refraction to bend them to a focus on the retina. Muscles in the ciliary body contract and the lens swells to a more rounded shape This makes it more powerful and the rays are bent more to achieve a focused image on the retina.

2.86 Eye as a receptor

2.86 describe the structure and function of the eye as a receptor

Information is collected by receptor cells, which are usually grouped together in sense organs, also know as receptors.

Each type of receptor is sensitive to a different find of change or stimulus.

The eye is a receptor that detects light.

The iris (right shaped, coloured part of the eye) controls the amount of light entering the eye by controlling the size of the hole in the centre, the pupil. The iris contains circular and radial muscles. In bright light the circular muscles contract and the radial muscles relax, making the pupil smaller. This reverses the amount of light entering the eye, as too much could to damage. The reverse happens in delight, when the eye has to collect as much light as possible to see clearly.

The thick clear cornea bends light rays as they enter the eye in order to bring them to a focus on the retina. The lens provides fine focus to sharpen the image.

ADH

2J ON MR. burrell’s Posterous bio blog
ADH – Anti-Diuretic Hormone
Stimulus: Concentration/composition of blood
Receptor: Brain – Hypothalamus
(Receptor to Coordinator = ‘Nerve’)
Coordinator: Pituitary Gland
(Coordinator to Effector = ADH)
Effector: collecting duct/ collecting tubule
Response: opening/closes of permiable (how much stuff going in and out) Collecting duct. Removal/reabsorption of water

The pituitary gland is where the ADH is created, in the Anterior lope in the Pituitary gland.

ADH is a chemical that travels through the blood. ADH in blood is called a hormone. The hormone is made in the Endocrine gland. Aim to reach the Target Gland or Target issue

Hormonal system = Endocrine system (just other name)

Endocrine gland >>>>(Hormone in blood) >>>> Target tissue or target gland.
Pituitary gland >>>>>>>>>>>>>>>>>>>>>>>>> Collecting tubualbe

In humans, hormones travel through blood

Hormone Endocrine gland Target tissue Effect
Oestrogen Ovary/Follicle The Uterus Increase thickness
Testosterone Testis Testis Matures sperm
Progesterone Corpus Luteum Uterus Maintains Thickness
Adrenaline Adrenal glands (kidneys) Heard/blood Increase Heart Rate
Insulin Pancreas Liver Glucose → Glycogen which is stored as Liver Glucose
Glucagon Pancreas Liver Opposite of Insulin

Monday, 30 January 2012

Obj 2.85

2.85 describe the structure and functioning of a simple reflex arc illustrated by the withdrawal of a finger from a hot object

Stimulus: Hot flame

Receptor: Heat sensor in the skin
- The impulse travels to the spinal cord along the sensory neurone.
- In the spinal cord the impulse is passes on to the relay neurone.
- This passes the impulse on to the MOTOR NEURONE.

Effector: Arm muscles
The motor neuron carries the impulse to the muscle in the arm

Response: Muscles contract to remove the hand from the hot object.

Click4Biology p123 (image won't upload)

Extra notes from class:
After Sensory Neurone instead of taking the CNS it takes the short cut to the Relay Neurone and then passes the impulse down the motor Neurone to respond. Short cut to make the reaction faster. Called a Reflex

Obj 2.84

2.84 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses

Your nervous system sends electrical messages along nerves to and from different parts of your body and they tell your body what to do.

Sense organs are our RECEPTORS (detect the change). They send messages to the central nervous system telling it what has happened. These messages are sent along sensory neurons.

Nerve cells are different from other cells. They do have a cell membrane; cytoplasm and nucleus by they are a different shape. Part of the cell is stretched out to form the AXON. The axon can be over a metre long.

The messages that nerves carry are called NERVE IMPLUSES.
They are electrical signals
They pass very quickly along the axon of the neuron.

Each impulse in separate from the next and they travel along one after another.

Some axons have a fatty sheath around them, which insulated the axon and make the impulse travel along faster.

2.83

2.83 recall that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves

The main parts of the nervous system are the BRAIN and the SPINAL CORD. Together they are called the CENTRAL NERVOUS SYSTEM. They are both made of delicate NERVOUS TISSUE. The brain is protected inside the SKULL. The Spinal Cord is protected inside you BACKBONE.

The central nervous system is connected to difference parts of the body by nerves. Each nerve is made up of lots of nerve cells or neurons.

obj 2.82

2.82 describe how responses can be controlled by nervous or by hormonal communication and understand the differences between the two systems

The nervous system controls your actions. It coordinates different parts of you body so that they work together and are able to bring about the correct responses. It coordinates you muscles, similarly it also works things we don’t notice happening such as swallowing, blinking and breathing.

The hormonal system also coordinates the body. Hormones are chemicals produced by glands, which are carried around the body in the blood. They tell different parts of the body what to do.

The differences -
Nervous system:
- Information passes as electrical impulses alone neurons
- Effects are rapid and short-lived
- Affects particular organs
- Often involves reflexes

Hormonal System:
- Information passes as chemical messengers in the blood
- Effects are usually slow and longer lasting
- Affects the whole of the body
- Controls growth, development, metabolism and reproduction

Tuesday, 24 January 2012

2.77b - Thermoregulation



2.77b
Negative feedback loop – method of control and maintaining constant conditions (i.e humans = body temp 37/38 degrees)
Receptor – Hypothalamus (region of brain), responds to stimulus of temp of body (blood).
If body temp needs to be altered, this is done through the job of the Effector (i.e the skin – sweating)
The response is the increase of decrease of temp.

obj 2.77a Thermoregulation



2.77a
homeo – ‘same’
Stasis – ‘fixedpoint/conditions’
Homeostasis – The conditions kept the same/constant
Thermic –temperature (Homeothermic- same temp)
Organisms (i.e Mammals) , when the environment temp changes (increases or decreases) then their body tem stays constant. These are HOMEOTHERMIC ORGANISMS. They carry out a process called Thermoregulation
Other organisms have body temp that varies with the environment.

2.9
- The max rate of reacted is achieved at the optimum temperature for that enzyme
The opt temp for the enzyme is approximately the same as the temp at which the mammals maintain their body conditions

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Obj 2.76 Sensitivity



obj 2.76
Sensitivity – The characteristic in which organisms respond to changes in their environment.
Changes = Light, Temp, Pressure and Chemicals.
In order to be able to detect these changed in the environment, organisms require having receptors and in in order to respond to the changes in the environment they have effectors (like muscles and glands). It’s the response that insures the organisms in able to survive the changes in the environment