Slide 1: Science Interactive LTD Multimedia CD-ROM for PC is a collection of 38 units totalling over 1150 PowerPoint slides matched to current single and double Science GCSE syllabuses. Each unit covers a wide range of different delivery and learning styles, offering an exciting way to involve your pupils during lessons or revision sessions. All styles of teaching and learning are supported through use of high quality images, graphics, challenging exercises and questions. Units can be used in the classroom via an interactive whiteboard, data projector or used during individual study via a PC or school network. Full users’ licence is available under our ‘comprehensive package’ or lessons can be purchased separately. Science Interactive LTD. PO BOX 50764 LONDON NW6 9AT email: firstname.lastname@example.org web: www:science-interactive.co.uk GCSE SCIENCE OCR EDEXCEL AQA Science Interactive LTD Copyright 2005 Slide 2: Unit 9
Photosynthesis in Green Plants Science Interactive LTD Copyright 2005 Slide 3: The anatomy and cell parts of the common plant cell.
The role of the chloroplast and mitochondria during photosynthesis and respiration.
The role of the leaf and the palisade cell during photosynthesis.
That the substrates for photosynthesis are water and carbon dioxide.
That the products of photosynthesis are glucose and oxygen.
That light energy is essential for photosynthesis to occur.
That the overall rate of photosynthesis is determined by limiting factors including carbon dioxide, light intensity, light colour and temperature.
That plants use glucose to make other molecules.
That plants can respond to stimuli like light, gravity and moisture. Leaf, Tissue, Organ, Cell, Palisade, Photosynthesis, Substrates, Water, Carbon dioxide, Products, Glucose, Oxygen, Light, Energy, Intensity, Limiting, Factors, Light, Temperature, Colour, Rate, Tropism & Stimuli. Unit 9: Photosynthesis in Green Plants web: www.science-interactive.co.uk email: email@example.com Science Interactive LTD PO BOX 50764 LONDON NW6 9AT Click mouse to begin Science Interactive LTD Copyright 2005 Slide 4: Levels of organisation in plants In plants, as in animals, similar cells performing similar f__________ are organised into tissues. Leaf palisade tissue consists of identical palisade cells functioning together to enable photosynthesis to occur. Other tissues found in green l________ also support photosynthesis. A leaf is an organ made up of many different tissues. Different organs work together as part of the entire plant organism. There are four distinct organs in a typical plant: The root system, the stem system, the leaf system and the reproductive system. Name the function of each of the four organ systems found in green plants ?
Cells, tissues, organs and organ systems in plants: Science Interactive LTD Copyright 2005 Word bank: functions leaves Slide 5: Plant leaf system A number of cells and tissues within the plant leaf play a role during photosynthesis, whereby water and carbon dioxide combine during photosynthesis to form g_______ and o_________. Palisade cells containing chloroplast are the main site of glucose production. Xylem tissue supplies water from the root and phloem tissue transports glucose made during photosynthesis around the plant. Gaseous exchange during photosynthesis and respiration is controlled by the stomata cells. Why are the stomata cells found only on the underside of the leaf ?
Plant leaf system: A B C D E Science Interactive LTD Copyright 2005 Word bank: glucose oxygen Slide 6: Specialised cells in plants Like animals, plants have many different s____________ cells performing different functions. Green plants have many examples of specialised cells that are designed for functions like photosynthesis, growth, reproduction, taking in w______ and minerals from the soil. The leaf palisade cell is a good example of a specialised cell in plants. It is well designed for photosynthesis, for example it contains many chloroplasts organelles, rich in chlorophyll. Where is the palisade tissue located in the plant ?
Specialised cells: Science Interactive LTD Copyright 2005 Word bank: specialised water Slide 7: The common plant cell Plant cells, like animals cells are made from many cell parts or organelles, each with a specific function. The common plant cell has some similarities and some differences to animal cells. This reflects differences in the way plants and animals feed and support themselves. The most important cell part is green c____________ containing chlorophyll which allows photosynthesis to occur.
Common plant cell: Science Interactive LTD Copyright 2005 Word bank: chloroplast Slide 8: Mitochondria and chloroplast organelles If you view plant and animals cells under a microscope, you can see tiny dots in the cytoplasm. These are the mitochondria. Cellular r____________ occurs in the mitochondria, releasing energy from glucose molecules. Plants also have green c____________ containing chlorophyll where water and carbon dioxide are combined to form glucose and o_________ during photosynthesis. Why do muscle cells contain more mitochondria than skin cells ?
Mitochondria and chloroplast: Membrane Membrane Matrix Matrix Science Interactive LTD Copyright 2005 Word bank: respiration chloroplast oxygen Slide 9: Plants as producers one Plants are called producers because they produce all the World’s biomass via a process called photosynthesis. Plants use energy from the s_____ to combine carbon dioxide and w________ to form g__________ and oxygen. This reaction produces millions of tonnes of living matter that nourishes all other living organisms in the animal kingdom. The oxygen that plants release into the atmosphere is used in cellular r_____________ by all living organisms. How can we determine the biomass of a plant ?
Plants as producers: Science Interactive LTD Copyright 2005 Word bank: sun water glucose respiration Slide 10: Plants as producers two The glucose produced during photosynthesis in green plants is used to make plant c____________, lipids and proteins. Every year over 70,000,000 kJ of sunlight energy falls on every metre squared of land. Plants only use about 90,000 kJ/m2/year of l_______ energy during photosynthesis, however they produce over 132 billion tonnes per annum of biomass. Overall plant yields depend on a number of factors including light availability, soil quality, rainfall levels and competition. How could you determine the yields of different crops over time ?
Plant yield and biomass: Science Interactive LTD Copyright 2005 Word bank: carbohydrates light Slide 11: Plants as producers three Plants are extremely efficient at transforming the energy carried by light to chemical energy trapped in glucose molecules, which are produced during p_____________. Their efficiency is about 80%, far higher than typical values for herbivores and carnivores. Only a small fraction of the c__________ energy they produce in the form of glucose is lost through respiration or waste. How could you determine the amount of glucose that is used during cellular respiration in plants ?
Plants using light energy: 1 1 2 2 3 3 Biomass Waste Respiration Biomass: Energy contained in the tissues of the plant (available for the next level.) Waste: Energy contained in the waste materials found in leaves. Respiration: Energy used in cellular respiration by all plant cells. 8,000 kJ 1,500 kJ 500 kJ Light energy
10,000kJ Science Interactive LTD Copyright 2005 Word bank: photosynthesis chemical Slide 12: Plants as producers four Plant leaves contain many palisade cells containing green c___________. Palisade cells use e______ from sunlight during photosynthesis to make g________ and oxygen. This palisade cell layer is found near to the surface of the leaf. Here it can absorb all the sunlight that falls on the leaf’s surface. How could you design an experiment to show that light is an essential factor for photosynthesis ?
Plants using light energy: A B C D E F G Science Interactive LTD Copyright 2005 Word bank: chloroplasts energy glucose Slide 13: Plants as producers five Every tissue found in green leaves, supports the production of glucose during photosynthesis. Palisade cells containing green c___________ have enzymes which use light energy to combine water and carbon dioxide forming glucose and oxygen. The xylem transports w______ from the root. Phloem tubes transport glucose to the rest of the plant. Stomata cells allows carbon dioxide from the atmosphere and promote transpiration. The spongy mesophyll allows carbon dioxide to diffuse quickly to the palisade cells. Why are the palisade cells filled with chloroplast found in the upper part of the leaf ?
Plants leaf structure and anatomy: Science Interactive LTD Copyright 2005 Word bank: chloroplast water Slide 14: Photosynthesis, the process whereby l______ energy is used by palisade cells found in green leaves to combine carbon dioxide and water to produce glucose and oxygen. This is the equation for the whole process.
From the equation we can see there are three requirements:
Substrates: Carbon dioxide and water
Requirements for photosynthesis: Photosynthesis and its equation one Carbon dioxide + Water Glucose + Oxygen Light and chlorophyll Science Interactive LTD Copyright 2005 Word bank: light Carbon dioxide Water Slide 15: Photosynthesis and its equation two From the equation for photosynthesis, we can determine the raw materials required during photosynthesis. Glucose production in green leaves will only occur if w_______ and carbon dioxide are supplied to the chloroplasts inside leaf palisade cells.
6CO2 + 6H20 C6H12O6 + 6O2
Carbon dioxide water light and chlorophyll Glucose Oxygen
Raw materials and photosynthetic products: 6 molecules of CO2 6 molecules of H2O 1 molecule of glucose 6 molecules of O2 Science Interactive LTD Copyright 2005 Word bank: water Slide 16: Reactions that take in energy from their surroundings in the form of heat or light are called endothermic reactions. Although these types of reactions are not as common as exothermic reactions, there are several examples. An important example of an endothermic reaction is photosynthesis, whereby light e_________ is used to combine water and carbon dioxide to form glucose and oxygen.
Energy changes during photosynthesis: Products Substrates C6H12O6 6O2 6H2O 6CO2 Activation energy Net energy taken in during reaction Photosynthesis and its equation three Science Interactive LTD Copyright 2005 Word bank: energy Progress of reaction Potential energy Slide 17: Sunlight, carbon dioxide, water and g______ chlorophyll are all essential for photosynthesis to take place inside a green leaf. Proving that these are essential, however requires experimentation. A series of experiments were carried out and are summarised in the table below. In brief, plants with no access over 48 hours to sunlight, chlorophyll or carbon dioxide were tested for starch in their l________. For each experiment, complete the results and give an explanation ?
Factors required for photosynthesis: Complete Complete Photosynthesis and its equation four Science Interactive LTD Copyright 2005 Word bank: green leaves Slide 18: Limiting factors for photosynthesis From the equation for photosynthesis, we can also determine the limiting factors affecting the r_______ of glucose production in green leaves. The rate of photosynthesis speeds up as light intensity increases, but only up to a point. The overall rate may also be limited by the concentration of carbon dioxide, the temperature or even the colour of light. Factors that can affect the rate of photosynthesis are called limiting factors.
Limiting factors: 6CO2 + 6H20 C6H12O6 + 6O2
Carbon dioxide water light and chlorophyll Glucose Oxygen Science Interactive LTD Copyright 2005 Word bank: rate Limiting factors light intensity one : Limiting factors light intensity one During photosynthesis, molecules of water and carbon dioxide collide, form new chemical bonds producing glucose and oxygen. The energy required to form these new bonds in glucose is provided by light energy. The rate of p____________ increases when the amount of light energy increases, but only up to a point. Other factors, like carbon dioxide concentration and temperature also affect the overall rate of photosynthesis. These are called limiting f__________. The factor in shortest supply will always be the limiting factor.
Affect of light intensity on the rate of photosynthesis: 0.1m 0.2m 0.3m Science Interactive LTD Copyright 2005 Word bank: photosynthesis factors 1: Plot a graph of distance (m) versus rate of oxygen production ?
2: Is there a relationship between light intensity and rate of photosynthesis ?
3: What is this relationship ?
4: What are the other limiting factors in this experiment ?
5: How could you test out you answer for question 4 ?
6: Why is important to control the temperature of the water ? Slide 20: Closed Open Closed Limiting factors light intensity two During the night, no photosynthesis takes place, just plant respiration. At dusk and dawn when the light intensity is low, the rate of respiration and photosynthesis are roughly the same. During the day, when there is greatest l______ energy, there is a net production of glucose and oxygen. The stomata cells, found on the underside of the leaf open during daylight hours when photosynthesis occurs and partially close during the night. Stomata are opened and closed by the guard cells changing shape. These guard cells contain chloroplasts, which provide the energy for stomata opening and closing.
Affect of light intensity on stomata opening and closing: Science Interactive LTD Copyright 2005 Word bank: light Limiting factors CO2 concentration : Limiting factors CO2 concentration The rate of photosynthesis increases when the concentration of carbon dioxide increases, but only up to a point. Other factors, like l______ intensity and temperature also affect the overall rate of photosynthesis in green plants. These are called limiting factors. The factor in shortest supply will always be the limiting factor.
Affect of CO2 concentration on the rate of photosynthesis: 0.1% CO2 0.25% CO2 0.5% CO2 0.1m 0.1m 0.1m Science Interactive LTD Copyright 2005 Word bank: light 1 :Plot a graph of CO2 concentration (%) versus rate of oxygen production ?
2: Is there a relationship between CO2 (%) concentration and the rate of
3: What is this relationship ?
4: What are the other limiting factors for this experiment ? Limiting factors temperature : Limiting factors temperature 25oC 35oC 45oC 0.1m 0.1m 0.1m The rate of photosynthesis in green plants increases when temperature is increased, but only up to a point, due to other limiting factors like carbon dioxide concentration and light intensity. This is because the two substrates; water and carbon dioxide have a higher kinetic energy, therefore colliding more often and with greater f_______ inside the palisade cell chloroplasts. Very high temperatures stop photosynthesis altogether. This is because, like other enzyme catalysed processes, plant enzymes are denatured when subjected to very high temperatures.
Affect of temperature on the rate of photosynthesis: Science Interactive LTD Copyright 2005 Word bank: force 1: Plot a graph of temperature (oC) versus rate of oxygen production ?
2: Is there a relationship between temperature and rate of photosynthesis ?
3: What is this relationship ?
4: What are the other limiting factors ?
5: Why, when the temperature was increased to 45oC in expt 3, was the rate of
photosynthesis very low ? Slide 23: Limiting factors colour of light The rate of photosynthesis can also be affected by the colour of light. This is because green chlorophyll absorbs r____ and b_____ light and reflects green. When green light is reflected, the light energy is not available to the chloroplasts during the formation of g__________ and oxygen from carbon dioxide and water. Why are many of the seaweeds found deep below the water’s surface red ?
Affect of light colour on the rate of photosynthesis: Green Red Blue White Science Interactive LTD Copyright 2005 Word bank: red blue glucose 1: Plot a graph of colour of light versus rate of oxygen production ?
2: Is there a relationship between colour of light and rate of photosynthesis ?
3: What is this relationship ?
4: What are the other limiting factors ?
5: Why is the rate of photosynthesis not zero for green light ?
6: Show in a diagram using a green plant leaf, what colours are absorbed and
reflected during photosynthesis ? Slide 24: Plant use of glucose general overview During photosynthesis in green plants, only glucose (C6H12O6) is manufactured. This glucose is then used by green plants for a number of uses including respiration, fruit production, g________ and repair. Plants are able to take a simple molecule like glucose and manufacture all the other types of molecules, including enzymes, l________, proteins and carbohydrates. They really are food factories and essential to all other animal life. Why is the word producers a good term to use when describing plants ?
Affect of light intensity on the rate of photosynthesis: Science Interactive LTD Copyright 2005 Word bank: growth lipids Slide 25: Pollination is the transfer of pollen, the male sex cells from the a_________ of the stamen by b____ or insects to the surface of the female c_________. Once the pollen sex cells have landed on the female carpel, pollination has been achieved. Flowering plants contain both female and male reproductive organs and can either self or cross pollinate. Following fertilisation, where the ovule and pollen cell fuse, the seed begins to develop surrounded by the swollen ovule which forms the f_______. It is the function of the fruit to disperse the seed. What is this organ’s role in the plant life cycle ?
Plant reproductive system: Plant use of glucose reproduction Science Interactive LTD Copyright 2005 Word bank: anther bees carpel fruit Slide 26: Plant use of glucose fruits and tubers It is the function of the fruit to disperse the seed. Fleshy fruits like apples, pears, oranges and tomatoes contain lots of sugar as a reward for a_________ and insects. These animals and insects, by eating fruit containing seeds, help spread the seeds prior to g_____________ during the following spring. Also roots tubers swollen with carbohydrates, like those found in carrots, turnips and potatoes act as a food reserve for new growth in the following spring. The sugar or carbohydrates contained in the fruit or root tubers is made during photosynthesis and is transported by the phloem tubes from the leaf.
Plant fruits and tubers: Science Interactive LTD Copyright 2005 Word bank: animals germination Slide 27: Tropisms in plants one Plants can respond to environmental stimuli like light, gravity and water. Unlike humans and other animals, plants cannot move themselves because they lack a skeletal m________ system. Plants can, however grow towards or away from a light source. Plant shoots grow towards the light, whereas plant roots grow towards gravity and moisture. If you germinated a seed in space with zero gravity, what would the growth response of the root be like ?
Plant reproductive system: Auxin accumulates on the dark side of the shoot causing cell elongation and the subsequent bending of the shoot towards the light source Science Interactive LTD Copyright 2005 Word bank: muscle Slide 28: Tropisms in plants two Plants must grow in one direction or another to respond to stimuli like light, moisture or even gravity. They can’t simply m_______ because thy don’t have a nervous or muscle system. The following experiments help us understand the role auxin plays in controlling a plant’s response. Look at the three different scenarios and predict where auxin is found and how this affects plant growth ?
Plant reproductive system: Science Interactive LTD Copyright 2005 Word bank: move Slide 29: 1: Define the following terms: Photosynthesis, Substrates, Products, Glucose, Oxygen, Limiting factors & Rate-limiting-factors.
2: Look at the diagram of the three types of leaf tissue. Complete the table.
3: Answer the following:
a) How does water and carbon dioxide arrive at the palisade cell for photosynthesis.
b) How is sugar transported around the plant.
c) Sugar is also used by all plant cells during respiration to produce energy for life processes in the plant. Compare photosynthesis and respiration.
d) During the day do plants respire.
e) How could you prove your answers in part (c) by performing an experiment. Explain all the steps.
f) Explain why the leaf cuticle is transparent. What other role does the cuticle play. Extension questions and homework Xylem tubes Palisade cells Stomata Science Interactive LTD Copyright 2005 Slide 30: 4: Look at the information in the table below. It shows the diameter of the stomata cells over a 24hr period:
a) Explain why the diameter changes over this 24hr period
b) At midday the light intensity is strongest. How do the stomata cells react to this.
c) At dawn and dusk, is the rate of respiration and photosynthesis the same.
5: a) Other than water and carbon dioxide, plants also need minerals (e.g. phosphates, nitrates and potassium) what are these minerals used for and how do the plants obtain them.
b) Show how a specialised root hair cell takes in minerals like nitrates from the soil.
c) Do the minerals given in part (a) give any energy value to the plant.
d) Compare those minerals that plants require for healthy growth to the minerals and vitamins we require in our own diet.
e) Somebody observed that wheat grows taller and gives a higher yield when the field is closer to a coal burning power station. Suggest a reason for this.
f) Explain why grass doesn’t need cutting during the winter months when the average daily temperature is below 6oC.
6: Complete the following:
Plants produce ____________ and oxygen during photosynthesis. This all takes place in the chloroplast found in the _______________ cells. The active chemical in the chloroplast is called _____________. It is able to use light energy to form new chemical bonds between water and carbon dioxide. Science Interactive LTD Copyright 2005 Slide 31: 7: a) Plants and crops need mineral salts for healthy growth. Give the name of three of these mineral salts.
b) A farmer wants to increase his crop yield by using fertilisers. The able below shows how mass of crop produced from a field depends on the quantity of nitrogen used.
(i) What is the maximum mass of crop that could be produced using nitrogen fertilisers.
(ii) Explain why using 700kg/hectare of fertilisers actually decreases crop yield compared to your answer in part (i).
(iii) Large amounts of fertilisers dissolve in water. When it rains fertilisers can accumulate in rivers and ponds. Explain why this is a problem.
(iv) Some consumers prefer organically grown crops. State two advantages and disadvantages of eating organically grown crops.
8: a) Explain the difference between ‘peat culture’ and ‘nutrient film’ hydroponics.
b) What are the benefits of intensive farming to the (i) farmer and (ii) consumer.
c) What are the disadvantages of intensive farming to (i) the consumer (ii) biodiversity (iii) the environment.
9: Complete the following:
Water passes into the root hair cell by ___________. Mineral salts like _____________ potassium and phosphate are taken up by active transport. A root hair cell has a ____________ surface area to help water and mineral salt uptake. Water is then transported through the ___________ tubes by capillary action to the leaf tissue. Palisade cells require water during photosynthesis to manufacture glucose. Water is lost through the leaves thorough the _____________. They are opened during the day and close at night when no p______________ takes place. Internet:
Go to google.co.uk and find out about fertilizers and how they provide essential minerals for healthy plant growth. Look at how the fertilizers are rated (N:P:K value) and what role each mineral plays in healthy plant growth. Science Interactive LTD Copyright 2005