What is Biology (and What Is Life?)

 What is Biology?

Biology is the study of life and living things. "Bio" means life and "logy" means the study of in Latin.

 What is Life?

Firstly, what are the characteristics of living organisms?

• Responds to stimuli
• Requires nutrition
• Requires oxygen
• It grows
• It dies eventually
• It produces waste

We then had a little discussion on the various characteristics

Nutrition 

consists of

• Feeding
• Digestion 
• Physical
• Chemical
• and Assimilation
• which is when food is broken down into simple diffusible forms to be absorbed by the body and converted into other forms, like muscle tissue and energy.

Respiration

• Energy is produced together with water and carbon dioxide
• One requirement is digested food, e.g. glucose*
• Aerobic (with oxygen)
• Glucose + Oxygen ------------> Energy+ water + carbon dioxide
• Anaerobic (without oxygen)
• Glucose-------------> Energy + alcohol + carbon dioxide (this can occur in wine)
• Glucose-------------> Energy + lactic acid+ carbon dioxide (occurs in humans)
• is stored in the muscles
• When it reaches the maximum amount of storage of lactic acid,
• it breaks down the acid by absorbing oxygen to prevent muscle soreness
• Even though we are aerobic creatures, we can carry out anaerobic respiration to complement aerobic respiration.

*Glucose is a carbohydrate.

Carbohydrates 

• Monosaccharides, (e.g glucose)
• Disaccharides
• and Polysaccharides. (e.g. Cellulose and glycogen)
• Glycogen is ONLY found in ANIMALS. It is the storage form of carbohydrates. Starch is also a storage form of carbohydrates, but ONLY in PLANTS.

The aim of digestion of

• lipids is to broken down into


• fatty acids 
• and glycerol
• carbohydrates


• into monosaccharides 
• Proteins


• into glucose 
• and amino acids

We also learnt a bit about water potential.

Water Potential → ability to donate water molecules

Looking at it from another POV, there would be more water potential in a more diluted drink than in a less diluted drink.The plasma has a low water potential compared to the cytoplasm of the cell. There must always be a comparison. Low water potential->Now wants to take water. Cytoplasm -> High water potential -> Wants to donate water