5.15 Genetically Modified Plants

• Maize
• Maize which is damaged by cork borer larvae reduces crop yield by 20%
• "BT", a bacteria that contains a chromosome with a gene that, when activated, produces "BT" toxins
• Can kill the cork borer larvae
• The DNA from the BT gene is cut with restriction enzymes
• isolates the desired gene
• Transferred to the cells of the maize plant via 'gene gun'
• Genegun fires a tiny golden pellet coated with DNA 
• DNA contains the desired BT gene
• Fired directly into young plant tissue
• The genetically modified tissue can be grown into new plants
• gives maize resistance againts damage from the cork borer larvae

5.14 Humulin

• The bacterial cell is transformed by the recombinant DNA
• Human DNA for the insulin gene is combined with the plasmid DNA
• A large population of the bacteria is injected into a fermenter
• Necessities
• Provides the right nutrients
• Controls the temperature
• Controls the pH level
• Controls the gases in the fermenting chamber
• Optimum temperature for bacterial growth > population increase + manifacture the protine insulin
• The insulin protein will be manufactured from the amino acid (nutrient protein) by the bacteria
• Necessary to remove the product to carry out purification by downstream processing
• This genetically engineered human insulin is called 'Humulin'

5.13 Recombinant DNA and Hosting Recombinant DNA

• Plasmid
• Found in bacterial cells
• Is a small circular piece of DNA
• Doesn't carry a lot genes
• Virus
• Contains Caspid
• protein shell
• Contains DNA/RNA
• A nucleic acid
• Has no nucleus or cytoplasm
• Human Chromosome 
• Identify the gene (Insulin- Hormone controling the blood sugar levels)
• The selected restriction enzyme cuts the DNA (Cuts the insulin gene)
• Cut the gene
• Isolate the plasmids and cut with the same enzyme
• the plasmids are now open allowing the insulin gene to be mixed
• Vector
• Transfers the gene into the plasmid
• The nucleic acid is removed from the virus to obtain the Caspid protein shell
• The virus takes the plasmids and acts as a vector for the recombiant DNA
• This helps transfer the DNA to the host
• Phage
• A type of virus
• Infects bacteria cells
• The virus is able to insert the recombinant DNA into the host cell by attaching itself to the cell membrane of the bacteria host
• the recombinant DNA and the human gene for insulin is now in the bacteria cell
• This is a combination called 'transgenic

5.9 Fish Farming

• Features that a fish should have
• High protine
• kow fat
• Able to turn nutrients into fish mass efficiently
• Advantages of fish farming
• Can control:
• Quality of water
• Predators
• Can reduce:
• pests
• bacteria
• diseases
• Can contribute to increase in yeild of fish
• Disadvantage
• High density fish = transition of disease
• Leads to the use of Antibiotics
• Pest becomes more common
• Leads to the use of pesticides
• Major concern to human health

5.8 Industrial Fermenter

• Aseptic precaution
• A pipe steam filled pipe
• fed into the fermenter in between session
• To sterilize the fermenter
• Nutrients
• Nutrients are fed in through pipes
• Can be opened or closed using valves
• Optimum Temperature and PH
• Has a sensitive prob to measure each
• Fermentation produces heat
• Fermenter is surrounded by a water jacket
• to prevent over heating
• water circulates and keeps temperature at the most efficient for growth
• PH can be adjusted by adding acids or alkali
• To keep it constant
• Oxygenation and Agitation
• Stirring paddles
• Stirs content
• located in the center of the fermenter
• Keeps microorganisms in suspension in the liquid
• They get more exposure to the nutrients that are fed in
• Agiation helps keep the temperature even in the fermenter

5.7 Yogurt production

Cow->Milk-> Pasteurization(kills bacteria)
                        V
Lactose(Milk sugar)-Incubate 45-46-> Lacticacid -> Lowers PH acidity
                        V
Milk solids solidify -> Yogurt

5.5 Beer production

• Beer
• An alcoholic substance
• Obtained through fermenting yeast in water
• Sugar from plant material is mixed in water
• Barley
• Converts sugar into ethanol and CO2 
• Yeast is a natural catalyst
• Sugar -> ethanol +CO2
• C6H1206 -enzyme in yeast-> 2CH5OH+2CO2
• The barley's starch is broken down into sugar
• Easier for the yeast to ferment it to ethanol
• When the barley seed germinates (Malting), it produces amylase (an enzyme)
• Breaks down starch into maltose
• Used by the yeast as an energy source
• Sugar from the barley is obtained through boiling it
• Hops are then added to adjust the flavor
• Also stops bacteria from growing
• Yeast is then added
• Uses up all oxygen and starts to respire

5.4 Pest Control and Biological Control

• Pest control
• Pests
• Organisms that reduces the yield of crops
• Damages farming
• Pesticides
• Can be used to kill pests
• Advantages
• Doesn't harm humans, only pests
• Helps to keep the yield strong
• All crops capable
• Easy to apply
• Disadvantages
• Expensive
• Pest can develop resistance
• Harmful to environment
• Can kill insects
• Pollinating ones are important
• Can wipe out food chain
• Not 100% effective
• Biological control
• Controlling pests through introducing their natural predetors
• Advantages
• No poison involved
• Almost all crops are affected
• Disadvantages
• Expensive
• Difficult to apply
• Not suitable for allcrops

5.3 Fertilizer

• Fertilisers contain minerals 
• nitrogen, phosphorus and potassium
• Helps plants grow Bigger + faster
• Crop yields are increased
• Nitrogen
• Makes protines
• Phosphates
• Make DNA/Membrane structure
• The minerals are dissolved first in water
• Plants can absorb them through the roots
• Active transport
• Types of fertilizer
• Organic Fertilizers
• Made from farmyard feces
• Mixture of animal manure and straw
• Goes through decomposition and fermentation
• Forms "Slurry"
• Applied to the fields afterwards
• Provides the important minerals for growth
• Inorganic/Artificial
• Made from inorganic compounds
• Potassium Nitrate
• Ammonium nitrate
• Formulated to obtain a specific amount carefully
• Applies as a solution with water
• The nitrates are released and absorbed by the roots
• Eutrophication
• Occurs when farmers apply inorganic fertilizers
• other mineral ions lost from removing the crops
• These ions are very soluble
• Easily leached from the soil
• Carried by water
• Can enter water ways
• Levels of the nitrates increases rapidly in lakes and rivers
• Increase in mineral ions
• Eutrophication
• Natural process resulting in bad waterways
• Due to the leaching ions
• Process
• Nitrate levels increase
• algae rreproduce rapidly
• Using the nitrates to make extra proteins
• Produces algai bloom
• Algea prevents light penetrating into water
• Plants unable to photosynthesize
• Dies
• Bacteria decay on dead plants
• Alge also dies
• Lack of nitrates
• The bacteria reproduces
• large amount of dead matter
• The water becomes anoxic
• without oxygen
• All life in the water dies

5.2 Crop Yields and CO2

• Rate of P/S
• CO2 + H2O -> Glucose + Oxygen
• Glucose -> Starch
• Increasing CO2 -> Increases the rate of reaction of P/S
• Higher Yeild
• Optimum Temperature
• Increasing temperature ->  Increases the rate of reaction of P/S
• Higher Yeild
• Optimum Temperature

5.1 Glasshouses

• Glasshouses are used to improve yield of crop

• Giving best possible conditions for photosynthesis
• Allows plants to grow earlier in the year
• Allows plants to grow in places in which they are not native to
• Can be controlled/manage via computer
• Conditions
• Temperature
• The sunlight heats the inside of the glass house
• The glass keeps the heat inside
• Electric/paraffin heaters can be used in cold weather
• Ventilators can cool the inside when too hot
• Light
• The glass lets sunlight in
• Artificial lights can be used when there is little/no sunlight
• Sunlight can be controlled using blinds
• Water
• Automatic watering systems can be installed
• Humidifiers can be installed to control the humidity

2.84 - 2.85 Nerve impulses and responses

• Nerve impulses pass through the CNS and the effectors create a respons
• Electrical impulses
• Signals/impulses created by the receptors which are send to the coordinator
• Method of transporting information of environmental change from the receptors to the coordinators in order to produce a response 
• Decision making
• When receptors are affected by a change, they sends eletrical signals/impulses through the sensory nerves to the CNS
• The brain then coordinates the response 
• Reflex action

• Very rapid, uncoordinated movement
• Ex: Pulling your leg up after stepping on a lego block in the dark
• Pain receptors detects the lego
• Sensory Nerve sends the electrical signal (Impulse) to the CNS, Brain
• The Motor nerve sends signals to the effector (Skin)
• The effector (Skin) produces a response
• Reflex
• Muscle contracts
• Leg is pulled up

2.83 Central Nervous System (CNS)

• Allows the body to respond to any change in the environment
• Consist of:
• Brain
• Spinal cord
• All the nerves branching out from the cord
•  The CNS refers only to only the brain and the spinal cord
• Impulses from the receptors pass through the sensory nerves til they reach the spinal cord and te brain
• There are two ways in which the CSN handles these changes:
• Response coordinated by the brain 
• Slower
• Reflex action
• Extra rapid responses to stimuli that by-pass the brain

2.82 Communication

• Motor Nerve (Neurone)
• Links coordinators with effectors
• Around a meter long
• Has tiny branches at each end
• Has long fibers at each end
• To carry the electrical impulses from the cell body to the Synaptic  knob
• Connected to the muscle
• Mammals- The axon is surrounded by a scwhan cell
• Contains fat to increase the speed of the nerve conduction
• Endocrine System
• Endocrine Gland 
• Produces hormones
• Can be Proteins/Steroids
• Secreted in to the blood
• Arrives at the "Target organ/tissue"
• May have multiple targets
• May have multiple effects
• Endocrine gland (Adrenal gland) > Blood (Adrenaline) > Target Tissue (Heart)
•                                |Nerves                                    |Hormones                      
  Speed of reaction     | fast                                        |slow                              
  Type of transmission|Chemical signal                       |Electrochemical signal
• Specificity                |Can be a few/many body parts|Affects target cells/organs
  

Receptors

ThermoReceptors-Temperature
GeoReceptors-Gravity
PhotoReceptors-Light
ChemoReceptors-Chemical
MecanicReceptors-Touch

2.77b Thermoregulation

• Receptors-
• Transforms external energy into internal electrical impulses
• Controls body temperature
• Human enzymes:
• Woks best at 37-38 degrees
• Dangers of body temperature
• High: Heat stroke, dehydration
• Death if not treated
• Low: Hyperthermia
• Death if not treated
• The brain monitors the body's temperature
• When too cold/hot, the brain sends nerve impulses to the skin
• Has 3 ways of increasing or decreasing lost heat from the surface of the body
• Hair standing up - 
• Traps more warm air which reduces heat loss
• Less when lying flat
• Capillary network
• allows blood to move further away from skin
• Tiny muscles controls the hairs
• Sweat
• Glands under the skin secret when hot
• increases heat loss through evaporation
• When the body is back at normal temperature, the skin stops secreting
• Capillary network
• allows blood to move closer to the surface skin
• Blood vessels supplying blood to the skin can cause the skin to swell or dilate
• Hot Day-
• Vasodilation
• The blood vessels dilate (widen)
• Hairs are flat
• More heat is carried by the blood to the skin
• Can be lost to the air through sweat
• Cold Day-
• Vasoconstriction
• The blood vessels swell (shrink down)
• Hairs are raised
• Reduces heat loss
• Returns body temp back to normal

2.77a Thermoregulation

• Homeostatis
• Homeo- Same
• Statis- Conditions
• Same conditions
• Homeothermic
• Thermic- Temperature
• Same Temperature

2.76 Sensitivity

• Sensitivity- Response to changes in the environment
• Changes:
• Chemical Level
• Light Level
• Temperature Level
• Characteristics of life:
• Movement 
• Respire
• Senses
• Grow
• Reproduce
• Excrete 
• Nutrition
• Receptors/Effectors in organism
• Receptors- To detect to change
• Effectors- To respond to change
• Response- 
• Organism is able to survive these changes