Biology Study Notes PDF

Enzymes: ​ Enzymes are proteins that act as catalysts to speed up chemical reactions in living organisms. They lower the activation energy required for reactions to take place. Enzymes are specific to the substrates they bind to and can be affected by factors like temperature, pH,...

Enzymes: ​ Enzymes are proteins that act as catalysts to speed up chemical reactions in living organisms. They lower the activation energy required for reactions to take place. Enzymes are specific to the substrates they bind to and can be affected by factors like temperature, pH, and concentration. ​ Example: Amylase is an enzyme that breaks down starch into sugars in the mouth. Photosynthesis: ​ Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy stored in glucose. This process occurs in the chloroplasts of plant cells. ​ The general equation for photosynthesis is:​ 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂ This means that carbon dioxide and water, using light energy, are converted into glucose and oxygen. ​ It consists of two main stages: the light-dependent reactions (which occur in the thylakoid membranes of chloroplasts) and the light-independent reactions (Calvin cycle), which occur in the stroma. Respiration: ​ Respiration is the process by which cells break down glucose (or other molecules) to release energy in the form of ATP (adenosine triphosphate). There are two main types: 1.​ Aerobic respiration (requires oxygen):​ Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP)​ This takes place in the mitochondria and is the most efficient form of energy production. 2.​ Anaerobic respiration (does not require oxygen):​ This process occurs when oxygen is scarce. In animals, it produces lactic acid, and in yeast, it produces ethanol and carbon dioxide. Anaerobic respiration produces less energy than aerobic respiration.