MICROORGANISMSCELLS AND MICROORGANISMS

Discuss the role of microorganisms in:– the digestive system– oxygen production– recycling nutrients via decomposition– recombinant DNA technology

Discuss the effects of temperature, nutrient availability, moisture, pHand the removal of wastes on bacterial growth.

Describe the causes of food spoilage, and explain the importance ofhygienic practices.

Describe techniques for preserving food. Relate each technique togrowth requirements of microorganisms and/or diffusion.

Overview

Microorganisms are important, microscopic living things.

Mircroorganisms

Discuss how microorganisms are involved in:

Activity

The Digestive System

Oxygen Production

Recycling Nutrients

Recombinant DNA Technology

INTENDED STUDENT LEARNING

Discuss the role of microorganisms in:the digestive systemoxygen production

recycling nutrients via decompositionrecombinant DNA technology

Microorganisms require specific conditions for growth.

For instance, microorganisms grow best at certaintemperatures, nutrient concentrations, pH and moisturelevels.

When these conditions are optimal, microorganisms will growextremely quickly.

Growth Conditions

INTENDED STUDENT LEARNING

Discuss the effects of temperature, nutrient availability, moisture, pH and the removal of wastes on bacterial

growth.

Microorganisms can cause food poisoning.

Many people become ill, or in extreme cases, can die due tobacterial contamination of food.

Safe hygiene practices are critical to prevent illness.

Food Spoilage

List safe food hygiene practices used to prevent bacterial contamination:

Activity

We can inhibit microbial growth on food with a range ofpreservation techniques.

Food Preservation

Conditions Preservation Technique

TemperatureMicrobes require specific temperatures for growth. Lowering the temperature (fridge) will slow down growth.High temperatures (oven) will kill many microbes.

pH Microbes require a specific pH for growth. Making food more acidic (pickling) will prevent microbial growth.

MoistureAll chemical reactions require water. Removing water through salting or dehydrating will make conditions unfavourable for microbial growth.Water is also unavailable when foods are frozen (water becomes ice)

Chemicals Chemicals such as sulphates can be used to inhibit microbial growth

Microorganisms

INTENDED STUDENT LEARNING

Describe the causes of food spoilage, and explain the importance of hygienic practices.

INTENDED STUDENT LEARNING

Describe techniques for preserving food. Relate each technique to growth requirements of microorganisms

and/or diffusion.

Complete the workbook questions in your books.

Questions

Homework

Independent content revision

Workbook questions