Biology Topic 4

Photosynthesis     -     Endothermic

• 6CO2 + 6H2O   =   C6H12O6 + 6O2
• Carbon dioxide + Water = Glucose + Oxygen
• Rate is affected by - fertilliser (Magnisium & nitrates), Chlorophyll (Makes plants green) and Green houses (Lighting, greater yield, higher temp).

Leaf Adaption

• Broad - Larger surface area.
• Thin - Shorter diffusion distance.
• Veins - Water in xylem, nutrients in the phloem.
• Air spaces - Diffusion, CO2 goes in & O2 goes out.
• Guard cells - Regulate gas exchange, open &close the stomata.

Carniverous Plants

• Soil is low in minerals so get nutrients from animals.

Anaerobic Respiration

• C6H12O6 = 2C3H6O3 + Energy 
• Glucose = Lactic acid + Energy
• Muscle fatigue - Stop contracting efficienctly.

Oxygen debt - Lactic acid + Oxygen = Carbon dioxide + Water

• Build up of lactic acid - causes cramping.

Aerobic Respiration

• C6H12O6 + 6O2 = 6CO2 = 6H2O + Energy
• Glucose + Oxygen = Carbon dioxide + Water + Energy
• Glucose is stored as oxygen.
• Exothermic
• Energy Transfer - Muscles contract, Internal body temperature, Plants transport minerals , For all life functions.

Response

• To increase the rate of supply of O2 & glucose - Heart rate increases & arteries dialate.
• Breathing rate increases - Remove CO2 quickly.
• Breath deeper - Increase O2 entering & picked up by red blood cells.
• Glycogen converted back to glucose for use.

Uses of Glucose in Plants

• Cellulose - Strengthen cell wall, complex carbohydrates.
• Fats & oils - Seeds, energy stored.
• Growth - Glucose & nitrates make amino acids.
• Starch - Boil leaf in ethanol, remove waxy cuticle, test in iodine, goes black.                        Storage and insoluable in water.

Metabolism - Sum of all chemical reactions that happen inside the cell.

• Breakdown of excess protein in the liver.
• Formation of lipids.
• Glucose to starch.
• Making proteins.
• Respiration & photosynthesis.

Role of the Liver

• Detoxifying poisonous substances e.g. alcohol.
• Breakdown old blood cells for storing iron.
• Converts lactic acids.
• Passes brokendown products into the blood.