GCSE OCR Biology B6

Cell Wall

Bacterial Cell have this - it prevents the cell from bursting

DNA Strand

Found in the Cytoplasm, controls cell actiivities and replication.

Plasmids

Small strands of DNA.

Flagellum

'Tail' of a bacteria - This helps them move.

Bacteria Shapes

Rods, Curved Rods, Spheres, Spirals.

Bacteria Survival

Can consume a huge number of organic nutrients. Some bacteria can produce their own nutrients. This means bacteria can survive in many different habitats.

Asexual Reproduction

Method of reproduction - replication of cells without another, different cell.

Binary Fission

Process of reproduction - means 'split in two'.

Bacteria Reproduction

Quick. Warm with a good source of nutrients.

Culturing Bacteria

Growing bacteria on an agar plate (or similar equipment)

Aseptic Techniques

Techniques to prevent youselve from infection. For example, sealing the petri dish.

Uses of Bacteria

Yoghurt, Insulin production

Virus Composition

Prortein coat with a strand of gentic material.

Reproduction of Viruses

Attaches to a host cell, infects, and break the cell, turning it into a virus 'powerhouse'

Disease Transmission

Food, Water, Airborne, Contact

Incidence of Disease

Number of new disease cases that occurs in a population in a certain time.

Natural Disasters lead to...

Bad sanitation, because everyone is cramped together. Also, hospitals are affected, therefore the healthcare will be worse.

Stages of Disease

Microorganism enters the body.
Reproduction
Toxin Production
Toxins cause symptoms.

Antiseptics

Used outside the body, they prevent infection.

Antibiotics

Inside the body, they kill bacteria to treat an infection.

Bacterial Mutations

Mutations in DNA can cause a bacteria to have a genetic advantage to others, so will reproduce rather than die. This could be in the form of Antibacterial Mutations.

Rules of Antibiotics

Don't take anti-biotics when you don't need them - this increase will create an advantage for mutated bacteria to re-produce. Also, complete your dose of anti-biotics, as not doing so will increasethe chance of resistant bacteria re-producing more.

Louis Pasteur

Argued that microbes were in the air which caused disease and decomposition.

Joseph Lister

First to use antiseptics (he used carbolic acid) in surgery to prevent 'sepsis'.

Alexander Fleming

Accidently discovered Penicillin - this medicine is a very good bacteria.

Anaerobic Respiration

Respiration to create energy when there is no oxygen present. This is called fermentation with Yeast.

Aerobic Respiration

Respiration to create energy when there is oxygen present. This is preferred by the Yeast.

Fermentation vs Aerobic in Yeast

Aerobic Respiration is preferred by yeast, as it creates more energy in comparison to fermentation. However, fermentation produces ethanol.

Yeast Growth Rate

The faster the Yeast respires, this is increased.

Temperature

Warm = faster growth rate
Too hot = enzyme denature

More food

More glucose = faster production

Toxic Waste

Build up of this slows production

pH

This has to be just right.

Uses of Yeast

To clean 'sugary' water from factories.

Beer

Germinate Barley. Add Yeast. Clearing agents. Pasteurised. (detail in revision guide)

Distillation

The act of heating up alcohol to 78 Degrees to evaporate the alcohol but not the water. This is condensed in a cooling tube and you are left with a high concentrated spirit.

Biomass

Living or dead (recently) organic matrial. It is a store of energy.

Biogas

Usually 70% Methane, 30% Carbon Dioxide. Made by a digester.

Uses of Biogas

Burned to power a turbine to Generate electricity, or heat water. Even some cars can run out it.

Digester

A tank in which sludge is placed to allow decomposition by microorganisms. creates methane through process of anaerobic digestion.

Advantages & Disadvantages of Biofuels

Advantages - Sustainable. Doesn't rely on fossil fuels. Can be made quickly. Doesn't create pollution, as plants absorb the Carbon Dioxide produced (it balances out)
Disadvantages - Not much energy in comparison to Fossil Fuels. Large amounts of land is needed to create this - destroying wildlife.

Ethanol

Used in alcohol, it can be also used a cleaner fuel in cars.

Gasohol

Usually 10% Ethanol and 90% Petrol. Produces less pollutants and is more sustainable than petrol itself. Good in fossil fuel poor areas.

Sandy Soils

Made up of large mineral particles, with large pores in the soil. Therefore, there is a high air content, and it is very permeable.

Pores

Gaps.

Permeable

Water can pass though this easily.

Clay Soils

Made up of Tiny mineral particles. Pak tightly, so small pores in the sol. Low air content and not very permeable

Loam Soils

Micture of sand and clay particles. Properties depend on levels of each type.

Humus

Decomposed, dead organic matter, which helps support life.

Humus & Water Content of Soil

Burn soil at 105 degrees until constant mass is acheived. This difference is water content. Heat at 550 degrees for 2 hours, and hummus will burn away. This difference is hummus content.

Air Content of Soil

Replace the air in soil with water - work out how much this is using a pipette. Water used to fill up soil until the top = air content.

Herbivore

Plant Eater

Carnivore

Meat Eater

Detritivores

Feed on dead organisms

Soil

Needed by plants for anchorage, water & minerals.

Conditions of Soil

Water and oxygen must be present. Presence of hummus is also important by giving off nurtients and minerals, and also increasing air content.

Worms

Are very useful in soil. They bury leaves which can be decomposed. They allow aeration. Allow drainage. Mix up the soil levels, distributing the nutrients equally. Neutralises soil acidity.

Aeration

Allowing air (oxygen) into the soil to help organisms respire.

Waterlogged Soil

A soil that is soaked or saturated with water.

Soil Acidity

These are less fertile than other pH's of soil.

Organisms with no Skeletal Systems

Water gives support for these organisms

Advantages & Disadvantages to living in water

Advantages - Plenty of Water. Less variation in temperature. Provides support (no skeletal system) good waste disposal.
Disadvantages - More resistant to movement than air. Water needs to be regulated (osmosis etc.). Fishing takes place.

Amoebas

Single-celled organism that control waer levels with a contractile vacuole.

Contractile Vacuoles

Collects the water that diffuses in by Osmosis, and then opens up at the edge of the cells to 'throw' water out again.

Plankton

Microscopic Organisms that live in fresh and salt water.

Phytoplankton

Microscopic Plants.

Zooplankton

Microscopic animals. They feed on Phytoplankton.

Photosynthesis factors

Temperature, Light Intensity, and Availability of Nitrates.

Plankton Population in the year

Winter - Low. Temp & Light Intensity is low. Mineral content is high, but this can't do photosynthesis.
Summer - High. Temp & Light Intensity is high. Mineral content is low, limiting photosynthesis.

Producer

Organism that produces it's own food.

'Marine Snow'

Dead, decomposing matter that has fallen from nearer the surface. Major source of Nutrients.

Eutrophication

Algae growing rapidly in water, dying, decomposing, and the bacteria starves animals in water from oxygen.

Pollution from Chemicals

If water is polluted with chemicals, these aren't always broken down by the organisms. When they are eaten the chemical passes on - an Otter eats lots of fish, so they would get a lot of this chemical.

Insoluble Chemicals

Starch, Proteins, Fats.

Non-biological Washing Powders

Break up Stains via Chemicals.

Biological Washing Powders

Contains Chemicals but also Enzymes to break up the 'stubborn' stains.

Amylases

Break down Carbohydrates into Simple Sugars. (Jam, Chocolate)

Lipases

Break down Lipids (fat) into fatty acids and Glycerol. (Butter & oil)

Proteases

Break down Proteins into Amino Acids (Blood, Grass)

Temperature of Biological Powders

Need to be washed at moderate wash temperature to pevent denaturing, however more resiliant enzymes are being developed.

pH of Biological Powders

Water needs to be neutral - Enzymes might not work at extremes of pH.

Special Stain Removers

Might contain solvents, or even specialised enzymes to break a stain down (blood, wine)

Diabetes

Diagnosed by presence of sugar in urine.

Benedict's Solution

When this is heated with urine, the colour of the solution goes from blue to orange if sugar is present. (Chemical Properties)

Reagent Strips

Strips of paper with Enzymes and Chemicals on it. They change colour if urine is present. Based on a sequence of enzyme reactions.

Low Calorie Food

Sucrase is aded to sucrose to make Glucose and Fructose, a much sweeter sugar.

Sucrose

Sugar we use at home

Sucrase

An enzyme that breaks down sucrose.

Rennet

Enzyme that causes milk to clot.

Pectinase

Used in fruit juice extraction. Breaks down Pectin that causes a release of juices.

Immobilised Enzymes

Enzymes that don't need to be seperated out of the mixture after the reaction has taken place.

Encapsulate

Enclose in a capsule

Alginate Beads

Formed by mixing the enzyme with Alginate, then dropping the mixture into a calcium chloride solution.

Avantages of Immobilising Enzymes

Enzymes don't contaminate the product. Immobilised enzymes in Alginate Beads can be used in continuous flow proccessing.

Lactose Intolerance

Gut Bacteria cannot be broken down by Lactase (produces Glucose and Galactose), so the gut bacteria ferment it. This causes Abdominal pain, Wind, Diarrhoea.

Lactose Free Milk

The Lactase in immobilised lactase breaks down the milk into glucose and galactose (simple sugars)

Immobilised Enzymes & Reagent Strips

Reagent strips use immobilised enzymes to quickly identify the glucose concentration in the blood

Genetic Engineering

Altering the genetic code of an organism. 'Good' genes are removed and interted into a different organism.

Transgenic Organism

A genetically modified Organism.

Gene Transfer

Is possible because DNA is universal. They all use the same 4 bases.