64711531_B2-1 PPT Photosynthesis and Cellular Respiration (1).ppt

HC5E Lesson B2-1 Photosynthesi s and Cellular Respiration 1  2 ENERGY TRANSFER Growth and development of plants is made possible by the transfer of energy.  3 The Nature of Light Apigment i...

HC5E Lesson B2-1 Photosynthesi s and Cellular Respiration 1  2 ENERGY TRANSFER Growth and development of plants is made possible by the transfer of energy.  3 The Nature of Light Apigment is any substance that absorbs light.  Thecolor of the pigment comes from the light that is reflected.  4 Structures  Photosynthesis occurs only in plants and a small number of bacteria (like algae).  Tobe able to photosynthesize, you must have a specific organelle: chloroplasts  5 Chloroplasts  Inside each chloroplast are what look like stacks of green pancakes.  Each pancake is called a thylakoids  Thestacks of thylakoids are known as granum  Empty space is known as stroma  Each thylakoid is lined with membranes  6 Photosynthesis takes place in chloroplasts.  A chloroplast is a cell organelle containing chlorophyll that traps light energy for photosynthesis.  Chlorophyll is the green pigment that gives plants their green color. Chloroplasts are generally found in the mesophyll cells of leaves. Typically, each mesophyll cell has 20 to 100 chloroplasts.  7 Components of chloroplasts  A fluid-filled region inside the chloroplast membrane that contains most of the crucial enzymes required for photosynthesis is the stroma.  A thylakoid is a membrane-bound disklike sac in which the light-dependent photosynthetic reactions occur.  A stack of thylakoid disks is a granum (plural: grana). Such a stack bears resemblance to a stack of coins. 8  9 Photosynthesis  Processby which plants build up and store the energy needed for food.  Photosynthesis takes place in chloroplasts  Photosynthesis occurs primarily in the leaves, but also in the stem, roots, and fruit tissues.  10 Photosynthes is Chlorophyll uses the energy in these compounds to split water molecules absorbed by the roots.  11 Light Reactions  Occurs in chloroplasts (thylakoid)  Converts light energy to chemical energy  Creates ATP (storage place for energy  Less influenced by temperature  12 Dark Reactions  Uses the ATP produced in the light reactions  Occursin the chloroplasts (thylakoid)  Converts carbon dioxide to oxygen  Influenced by temperature  13 What is a photosynthetic reaction?  14 What is a photosynthetic reaction?  15 Factors affecting Photosynthesis  Light quality, intensity, duration  Carbon dioxide concentration  Temperature  Water Availability  16 Carbon Dioxide Concentration  Percentage in atmosphere is.035%  When increased to.10%, the rate of photosynthesis increases  Carbondioxide concentrations can be controlled in greenhouses  17 Carbon Dioxide Concentration  Roses, orchids, and carnations are grown in enriched carbon dioxide environments  Plants take in carbon dioxide through the stomata in the leaves  When soil moisture is low, the stomata closes  This restricts intake of carbon dioxide, which reduces the photosynthetic rate  18 Temperature  Varies by species  Rateof photosynthesis increases for each 50 degree F increase to certain point  Toohigh of temperature can hinder photosynthesis  19 Light quality, intensity, duration  Quality refers to number of photons  Intensityis the measure of brightness of the light  Duration  The longer the duration, the greater the rate of photosynthesis and growth  Photoperiodism refers to the specific light duration requirements of plants in order to initiate flowering  20 ENERGY TRANSFER  21 Respiration  Releaseof energy captured and stored through photosynthesis  Duringrespiration, carbohydrates are converted to carbon dioxide, water, and energy  Thisenergy is the source of energy for plant’s life processes  Occurs continuously in plant cells  22 Respiration  Respiration occurs continuously in plants, photosynthesis occurs only in presence of light  Affected by:  Temperature  Oxygen  Water availability  23 Temperature  Very strong effect  Increases2-4 times with each 50 degree F increase, which means a decrease in plant growth  Plantsgrow best when nighttime temperatures are 9 degrees F cooler than daytime temperature  24 Water Availability  Important for enzymatic reactions Oxygen respiration decreases as oxygen decreases  25 What are the two types of cellular respiration?  26 ENERGY TRANSFER  27 Photosynthes is  28 Photosynthes is  Oxygen escapes through stomata (singular: stoma) into the atmosphere.  A stoma is a tiny pore in the epidermis of a leaf that regulates the exchange of gases.  It is through stomata that a plant obtains carbon dioxide produced during photosynthesis and releases oxygen.  The opening and closing of the stomata are affected by environmental and chemical changes.  29 Photosynthes is  30 Photosynthes is  31 What is cellular respiration?  32 What are the two types of cellular respiration? Aerobic respiration is cellular respiration that occurs in the presence of oxygen. It is essentially the reverse of photosynthesis Four Stages of Aerobic Respiration 33  34 What are the two types of cellular respiration? When oxygen levels are low, organisms can still respire, but the process is slightly different.  35 Assess what you’ve learned 1. How are plants capable of absorbing solar energy, converting it into stored chemical energy, and using that stored energy? 2. Analyze the process of photosynthesis. 3. Examine the process of cellular respiration.