Chapter 4

Question 1

Optimum condition

Answer 1

Each microbe has an optimum condition for growth and a range in which less growth is possible, outside the optimum condition the activity of the enzyme will be lower thus lowering growth of the microbe

Question 2

What happens when optimum conditions are not met?

Answer 2

When the microbe is in the optimum environment condition, the enzyme can fold correctly lead to optimal temperature, slight variations outside can lower enzyme activity, thus lowering the microbes growth due to misfolding of enzyme, when microbes are outside optimum min/max the proteins will misfold causing cell death

Question 3

Effect of temperature on microbial growth

Answer 3

Thermal energy plays a crucial role in movement of MOLECULES, structures, and function of cells proteins and membranes. PSYCHROPHILE (-5-20 degrees celsius) MESOPHILE (15-45) THERMOPHILE (40-80) EXTREME THERMOPHILE (80-121)

Question 4

Effect of osmotic pressure on microbial growth

Answer 4

Osmotic pressure is the force water exerts on the semi-permeable membrane surrounding the cell. ISOTONIC ENVIRONMENT (solute concentration same inside as outside of cell, equal movement of water) HYPOTONIC ENVIRONMENT (most, high solute inside cell, water move inside solutes out causing cell to swell) HYPERTONIC ENVIRONMENT (high solute outside cell, water move out, result in drying out and cell death)