CHAPTER ENERGY!

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1 CHAPTER 8.1 ENERGY!

2 8.1 What is energy? Energy- The ability to do work Thermodynamics- is the study of the flow and transformation of energy in the universe. *All cells need energy for many Functions that they carry out to stay alive

3 Types of Energy Chemical- energy found in bonds between atoms of every molecule: Released when bonds break Glucose: Sugar that is major energy source, used to make ATP (ENERGY!!) Solar Energy- Energy from Sunlight: Can t be used directly: Plants convert solar energy to usable chemical energy (Glucose)

4 Laws of Thermodynamics First law energy can be converted from one form to another, but it cannot be created nor destroyed. Ex. Chemical Energy to Mechanical Energy

5 Laws of Thermodynamics Second law energy cannot be converted without the loss of usable energy. Ex. Energy Lost as Heat

6 Second Law continued... Entropy Measure of disorder (randomness) Measure of unusable energy

7 Two types of reactions Endothermic- uses energy to make bonds H+H H2 Energy put in Exothermic- breaks bonds and releases energy H2 H + H Energy Released

8 Metabolism Metabolism: All chemical reactions in a cell Two types of Metabolic Pathways: Catabolic: Release energy by breaking down larger molecules Anabolic: Use energy to build larger molecules from smaller ones

9 Think - Pair - Share Of the following examples, list which ones are catabolic and anabolic 1. Amino acids becoming polypeptide chain 2. Glucose becoming glycogen 3. Your body breaking down food

10 ATP - Adenosine Tri Phosphate Structure: Adenine base, ribose sugar, and 3 phosphate groups

11 ATP - Adenosine Tri Phosphate Function: - bond breaks between the second and third phosphate groups to release energy - Creating adenosine diphosphate (ADP) and a free phosphate group.

12 Processes involving energy Cellular respiration organic molecules are broken down to release energy for use by the cell Photosynthesis light energy from the Sun is converted to chemical energy for use by the cell

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14 Biogeochemical cycles

15 Cycles Biogeochemical cycle- exchange of matter through the biosphere. Energy is transformed into usable forms Cycling of nutrients in the biosphere involves: Matter in living organisms Physical processes found in the environment

16 What do you think? Q: Why is it important to living organisms that nutrients cycle? Q: What would happen if matter bound in living matter and never recycled?

17 Q: Why is it important to living organisms that nutrients cycle? A: Cycling makes nutrients available for other organisms to use. Q: What would happen if matter bound in living matter and never recycled? A: Nutrients would eventually be depleted and life would cease to exist!

18 Water cycle What processes are involved? Think back to your past science class!

19 Water cycle Animations Videos

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21 Precipitation = Water falls from the clouds as rain, sleet, snow, or hail Surface runoff and groundwater flow into streams, rivers, lakes, and oceans.

22 Evaporation - liquid turns into a gaseous state Water from the rivers, oceans, and lakes evaporates into the atmosphere 90% evaporates from oceans, lakes and rivers. 10% evaporates from surface of plants Transpiration - The process where plants absorb water through the roots and then give off water vapor through pores in their leaves

23 Water Cycle Water evaporates and forms into water vapor (gas) in the atmosphere Condensation: Water vapor rises, cools, and condenses into droplets, which then makes clouds!

24 Water Cycle Precipitation runs off and can enter/ be stored as: 1. Rivers, lakes, oceans, etc. 2. Groundwater 3. Aquifer - a body of permeable rock that can contain or transmit groundwater 4. Percolation in soil for plant uptake - Infiltration

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27 The Nitrogen Cycle

28 Nitrogen Cycle The series of processes by which nitrogen and nitrogen containing compounds are interconverted in the environment and in living organisms Nitrogen (N) element needed to make proteins - Can exist as a gas (N2) = 78% - Bonds to make other compounds (NH3, NH4, etc) Consumers get nitrogen by eating plants or animals that contain nitrogen

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31 Nitrogen Cycle 5 Main Steps! 1. Nitrogen fixation = Special bacteria convert the nitrogen gas (N2) to ammonia (NH3/NH4 +), which plants can use. 2. Nitrification = Process which converts ammonia (NH3/NH4 +) into nitrite/nitrate ions (NO2 NO3 ) Plants can take up nitrates and ammonia. 3. Ammonification = Decomposers convert the nitrogen rich waste into simpler ones ( NH3) 4. Denitrification = Bacteria convert the simple nitrogen compounds back into

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33 Nitrogen Cycle Nitrogen is returned to the soil in several ways: 1. Animals die or urinate. 2. Nitrogen gas (N2) taken into soil Nitrogen Fixation: Conversion of nitrogen from atmosphere into ammonia Ex. Nitrogen fixing bacteria & lightening bolts.

34 Nitrogen Cycle Nitrification:Organisms in the soil (nitrogen fixing bacteria) convert ammonia into nitrogen compounds (nitrites then nitrates). Nitrates will be used by plants. Denitrification: takes nitrates and converts it back to

35 Nitrogen Cycle Ammonification: converts nitrogen to ammonia (NH3) - Usually comes from animal waste - Performed by bacteria Assimilation: Plants take up nitrogen (ammonia & nitrates) - animals assimilate their nitrogen by eating plants

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38 Nitrogen Fixation Animations

39 Soil Testing Lab Please take out your soil and water!

40 The Carbon Cycle

41 The Carbon Cycle -

42 What is a Carbon Sink? - A natural or artificial reservoir, such as the forest, ocean, soil, and atmosphere, that have the ability to absorb carbon containing chemical compounds - Absorbs more than it puts out!

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44 Combustion - fossil fuels in the ground and factors emit CO2 into the air Fossil Fuels - A natural fuel, such as coal, oil, and gas, formed in the geological past from the remains of living organisms

45 Cellular Respiration - Organisms take in oxygen from the air (and eat in order to obtain glucose) - Animals and plants (yes, plants!) give off CO2

46 PhotosynthEsiS - Plants take in CO2 from the atmosphere and give off oxygen - Fossil fuels are formed in the ground from decayed plants and animals over a long period of time - Crude oil, coal, natural gas, heavy oils = fossil fuels

47 Carbon in the Oceans - Carbon is sequestered into the oceans, which currently take up a third of the carbon emitted by human activity = Roughly two billion metric tons each year! - However, this is acidifying the ocean (lowering the ph). Why?

48 Carbon in the Oceans - CO2 + H2O bind with carbonate ions to create bicarbonate ions. - The carbonate ions are the building blocks for many organism s skeletons. CO2 is decreasing the amount of carbonate ions that they can use to create their shells

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51 Do Now - How do humans influence the environment? - Is this positive or negative? - List some examples!

52 Human Impact Humans have influenced about 83% of Earth s surface: Does this seem like a lot or a little? Some areas are more vulnerable than others, why?

53 Human Impact Today s global population approx. 7 billion people Year 2300 = 36 billion people! How will a growing population affect people s access to food, water, and fuel? Wildlife habitats?

54 Activity! You may work with a partner, or work individually. If you finish early, you may begin on your homework by measuring your own ecological footprint!