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34 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is the equation for photosynthesis? |
6CO2 + 6H2O - > C6H12O6+ 6O2 |
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What is photosynthesis? |
Endothermic reaction, energy transferred from environment to chloroplasts by light. Uses water, co2 and sunlight to produce oxygen and glucose which can be stored as starch. Reactants go though pigment of the leaf and chlorophyll executes this reaction. Glucose used as energy and in respiration. |
Endothermic. Environment to plant via light. Reactants? - go through pigment Products? Chlorophyll executes, glucose energy in respiration. |
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Test for starch? |
Boil beaker of water. Put leaf in there to stop photosynthesis and removes wax layer. Put leaf in test tube /w ethanol and put that in beaker. Ethanol removes chlorophyll. Wash in warm water ; soften leaf. Add iodine to leaf. Then check results. |
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What is the purpose of the chlorophyll? |
Pigment in chloroplasts Light - > chemical energy Synthesise carbohydrates (glucose) |
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What factors limit the rate of photosynthesis? |
Light intensity Co2 conc. Temp Amt. of chlorophyll |
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Why do we turn the bunsen burner off when testing for starch? |
Ethanol is very flammable |
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5 conditions for photosynthesis? |
Suitable temp range Availability of water + co2 More chlorophyll In sunlight for chlorophyll to absorb |
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How is glucose used in photosynthesis? |
Respiration Converted to insoluble starch - storage Produce fat /oil - storage Produce cellulose for cell wall strength Produce amino acids for protein synthesis |
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How do greenhouse farmers increase rate of photosynthesis and maintain profit? |
Propane burner - useful in winter so plants can grow at optimum temp therefore optimum rate - can sell all year round Thermostatically controlled vents - control temp in greenhouse for optimum temp for plants to grow. Carbon dioxide pumper - gives plants co2 for photosynthesis increases rate of plant growth. Water pumping system - keeps all your plants hydrated, water required for photosynthesis perfect balance is given |
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What is the relationship between distance and light? |
Greater the distance (between plant and light) less oxygen produced so less the rate of photosynthesis. |
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Explain the practical for investigating how light intensity affects photosynthesis |
Test tube rack with boiling tube Fill with sodium hydroxide carbonate solution Put pondweed into boiling tube with cut end at top. Push in /w glass rod. Leave for 5 mins. Start stopwatch and count no. of bubbles in 1 min. Repeat three times and take avg. Then move back another 10 cm and repeat up to 40 cm. |
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What are the adaptations of a leaf? |
Large s.a. - to maximise amt. of light reaching and falling on the leaf Lots of chloroplasts - more absorbs more light for photosynthesis Veins (xylem and phloem) helps nutrients and water to be carried round the plant. Air spaces - allows gases to enter via diffusion Guard cells - allow what substances go in/out through stomata which opens and closes - regulates gas exchange |
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Light intensity equation? |
Light intensity proportional to 1/distance ^2 |
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What is respiration? |
Exothermic process carried out continuously by all living cells to produce energy that involves action of enzymes. |
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What is the equation for respiration? |
C6H12O6 + 6O2 -> 6CO2 + 6H2O (+energy) |
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What does the human body need energy for? |
Muscle contraction Protein synthesis Cell division Active transport, diffusion and osmosis Growth Nerve impulses Maintaining constant body temp |
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Does aerobic respiration or anaerobic respiration release more energy? |
Aerobic does - with more O2. |
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What is anaerobic respiration? |
Respiration without oxygen |
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What is the equations for anaerobic respiration? |
Fermentation: C6H12O6 -> 2C3H606 + CO2
Vigorous exercise: C6H12O6 -> 2C3H6O3 |
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Why does heart rate + breathing rate increase when you exercise? |
Muscles use O2 and C6H12O6 which are needed for respiration. For muscles to respire faster need more blood which contains glucose and oxygen to be pumped to where it is needed. So the heart rate increases. Takes away CO2 faster. |
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More oxygen can be breathed into lungs than into bloodstream. CO2 can diffuse from bloodstream into lungs to be breathed out. Water vapour also breathed out. |
Ok |
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Why do we need energy? |
Chemical reactions to build larger molecules Movement Keeping warm |
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What is oxygen debt? |
Amount of extra oxygen body needs after exercise to react with buildup of lactic acid and remove it from cells. Blood flowing through muscles transports it to liver where it is converted back to glucose. |
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What is metabolism? |
Sum of all the chemical reactions in a cell or the body. Energy from respiration used for continuous enzyme controlled processes of metabolism that synthesise new molecules. |
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What do glucose and nitrate ions form? |
Amino acids that synthesise proteins. |
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Formation of lipid molecules from a molecule of glycerol and three molecules of fatty acid. |
Ok |
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Why would there be an increase in lactic acid during exercise? |
Because of anaerobic respiration and lactic acid being a product of that and because glucose not completely oxidised. |
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What does a long period of vigorous exercise do to the muscles? |
Creates lactic acid from anaerobic respiration which increases muscle fatigue and causes pain, stopping contractions. |
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What do plant hormones control? |
Growth - roots+shoots, seed germination, leaf fall, disease resistance, fruit formation + ripening, flowering time, bud formation |
Root-shoot , seedy leaf, resist, fruit 1) 2) flower bud |
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What is a tropism? |
Responses of plant roots and shoots to phototropism and gravotropism |
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What are auxins and where are they found? |
Hormones released by shoot/root tip - build up/travel along shaded side of them Shaded grows more than unshaded so bends towards light |
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What is phototropism? |
Plant's growth response to light Pos. - towards light (stem tip) to get Max light for photosynthesis Neg. - away from light (root tip) less chance of drying out |
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What is gravotropism? |
Plant's growth response to earth's grav. Field Pos. - towards gravity (by roots) Neg. - away from gravity (Root tip - produce auxins build up on lower sides stunts cell growth so bends downward and grows) |
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What can plant hormones be used for? |
Auxins - promote growth in tissue culture, - selective weedkiller (excess growth so dies), rooting powder Gibberellins - promote flowering, increase fruit size, end dormancy in seeds (Ethene - fruit ripening) |
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