B1

• word equation for photosynthesis

  Carbon dioxide + water —> glucose + oxygen
• photosynthesis is the process by which plants make their own food
• balanced equation for photosynthesis: 6CO2 + 6H2O -> C6H12O6 + 6O2
• Photosynthesis is an exothermic reaction in which energy is transferred from the environment to the chloroplast by light
• the rate of photosynthesis is effected by light intensity because not havin a lot of light means less energy is available for photosynthesis
• the rate of photosynthesis is effected by temperature because if the temperature is too low the enzymes needed for photosynthesis work more slowly
• the rate of photosynthesis is controlled by the light intensity, temperature and carbon dioxide concentration
• the rate of photosynthesis is affected by the carbon dioxide concentration because too little carbon dioxide will slow down the rate of photosynthesis
• any factor of photosynthesis can be a limiting factor
• Inverse square law: light intensity is inversely proportional to the square of the distance
• limiting factors are important in the economics of greenhouses to gain the maximum rate of photosynthesis while still maintaining a profit
• the glucose produced in photosynthesis can be used for: respiration, stored as starch, used to produce amino acids for protein synthesis, used to produce cellulose for cell walls
• respiration is an exothermic reaction constantly occurring in cells
• aerobic : respiration using oxygen
• anaerobic : respiration without using oxygen
• organisms need energy for : movement, warmth, chemical reactions to build larger molecules
• word equation for aerobic respiration: glucose + oxygen -> carbon dioxide + water
• word equation for anaerobic respiration: glucose —> lactic acid
• As the oxidation of glucose is incomplete in anaerobic respiration much less energy is transferred than in aerobic respiration.
• anaerobic respiration in yeast: glucose -> ethanol + carbon dioxide
• Anaerobic respiration in yeast cells is called fermentation and has economic importance in the manufacture of bread and alcoholic drinks.
• During exercise the human body reacts to the increased demand for energy
• The heart rate, breathing rate and breath volume increase during exercise to supply the muscles with more oxygenated blood.
• If insufficient oxygen is supplied anaerobic respiration takes place in muscles
• The incomplete oxidation of glucose causes a build up of lactic acid and creates an oxygen debt
• During long periods of vigorous activity muscles become fatigued and stop contracting efficiently
• Blood flowing through the muscles transports the lactic acid to the liver where it is converted back into glucose
• Oxygen debt is the amount of extra oxygen the body needs after exercise to react with the accumulated lactic acid and remove it from the cells
• Metabolism is the sum of all the reactions in a cell or the body.
• Pathogens are microorganisms that cause infectious diseases in animals and plants
• bacteria produce toxins that damage your cells and tissues
• viruses reproduce rapidly inside your body
• viruses live inside your cells and replicate in the cells eventually causing the cells to burst
• protists live on or inside an organism and cause them damage
• protists are often transferred to the organism by a vector
• a vector is an insect that carries the disease
• fungi can grow and penetrate human skin and the surface of plants causing diseases
• pathogens can be spread by water, air and direct contact
• spread of diseases can be reduced by being hygienic, destroying vectors, isolating infected individuals, vaccination, and quarantine
• Measles is a viral disease showing symptoms of fever and a red skin rash