NCEA Level 1 Microorganisms

Antibodies

Antibodies

Proteins produced by the body as part of the immune response.

Antigens

A substance that the body treats as foreign and initiates an immune response.

Capsid

Outer protein coat of a virus

Eukaryote

A cell that contains a nucleus and membrane bound organelles

extremophiles

Bacteria that live in extreme environments. Halo (salt), Thermo(heat), acid (acid), Xero (dry).

Fungi

A group of microorganisms that can exist as either unicellular or multicellular. They have a nucleus bound by a membrane so they are eukaryotic.

Incubate

The right conditions, e.g. temperature, moisture, pH, nutrients for a micro-organism to survive.

Lymphocytes

Type of white blood cell formed in the lymph nodes and help fight infections.

Phagocytes

A cell that is part of the immune response. It engulfs and breaks down foreign particles. The process is called phagocytosis.

Tail Fibres

a hollow tube which genetic material passes through during infection.

vaccinate / vaccination

To inoculate with a vaccine to produce immunity to specific disease.

virus

A very small particle that invades a host cell and uses its cellular processes to produce more viruses. It is a pathogen. Also known as a Bacteriophage which attacks bacteria.

Aerobic Respiration Equation in bacteria and fungi

Sugar + Oxygen -------> Carbon dioxide + Water +lots of energy

What is the optimal temp for bacterial growth/reprouduction?

30 - 40

What happens after 60 degrees?

Bacteria die.

Mutalistic Bacteria

The feed of living tissue but both the host and the bacteria receive some benefit.

Commercialist Bacteria

Bacteria which does no harm nor good to its host.

Respiration

The extraction of energy from food and the conservation of that energy into forms the bacteria can use.

What are the favourable conditions for growth?

Oxygen level (if aerobic), PH, Toxins, antibiotics, disinfectants and competition.

Why is temp a condition?

Enzymes reactions work best at an optimal temperature, not too hot and not too cold, about 30-40. If it gets too hot or cold the enzymes denature.

The effect of PH

PH ranges outside 5-9PH are harmful, and they will denature.

Osmotis

The movement of water from an area of high water concentration to an area of low water concentration through a semi-permeable membrane.

The Effect Of Water

If a microbe is placed in an environment where the solute concentration is not equal then water will leave or enter the cell via osmosis. Causing the cell to swell or shrink and die.

capsid

A protein coat that surrounds a viruses nucleic acid. Some viruses contain DNA and other RNA.

Endo

Internal

Sterile

A product which is completely free of microorganisms

Pasteurisation

To process of heating a food to a specific temperature for a time to kill microorganisms.

Denature

Take away or alter the natural qualitys of microorganisms.

Toxic

A substance that is able to cause illness or death or is damaging to the environment.

How can you preserve food?

Low temp, dehydration, chemical preservation, heating, irradiation.

How does dehydration preserve food?

Reduces the amount of water needed for bacterial growth.

Irradiation

By Damaging the DNA of the microbe beyond repair

Chemical with salt

Draws moisture from the food by osmosis. Salting also causes bacterial cells to lose water via osmosis therefore will kill microbes already present on the food.

Chemically with vinegar

Vinegar is an acid that will lower the PH. A change in pH may cause the cell membrane to dissolve. It may also denature digestive and respiratory enzymes resulting in microbial death. The lower Ph will prevent recontamination.

Lower Temperatures

Lower temperatures are used to preserve food by lowing microbial reproduction through the reduction of microbial enzyme activity. Lowing the temperature lowers the rate at which enzymes can digest food.

Heating

By denaturing the enzymes or by killing the microorganism its self.

Decomposer

Break down dead organic matter releasing carbon dioxide into the atmosphere.

Nitrogen-fixing bacteria

Convert nitrogen gas from the air into compounds such as nitrates.

Decomposer in nitrogen cycle

Convert nitrogen-containing compounds (such as amino acids) found in dead material and animal excretion into nitrates.

Denitrifying Bacteria

Convert nitrates back into nitrogen gas that is released back into the atmosphere.