Energy Chapter 4
Energy = Capacity to do Work Kinetic = Energy of Moving Objects Potential = Stored Energy
Laws of Thermodynamics • Energy can not be created or destroyed • Energy can change forms – heat, light, chemical, matter
Which of the following is NOT a form of kinetic energy? A) a ball rolling down a hillB) flowing water turning a turbineC) a chameleon tongue catching a bugD) a covalent bond linking phosphate moleculesE) a pitcher throwing a baseball
The first law of thermodynamics states that energy is constant; it can _________, but not __________. A) be transferred and transformed; created or destroyed B) be produced and generated; moved or relocated C) hustle; flow D) be increased and decreased; eliminated E) cycle; flow
Photosynthesis • Uses about 1% or less of energy from sun • 30% is reflected back into space or • 70% absorbed by Earth and converted to heat energy
Photosynthesis process1. Photo reaction Sunlight + water = energy + Oxygen2. Synthesis reaction Carbon dioxide + energy = sugar
Energy supporting most of the life on this planet originally came from: A) water.B) sunlight.C) sugar molecules. D) oxygen.E) carbohydrate molecules.
How is Light Energy Captured? • Plants have pigments that can absorb light of certain wavelengths
Light Energy • Light is a form of kinetic energy that is packets of energy called photons moving in a wave • Different sizes of wave produce the different parts of electromagnetic spectrum • Our eyes can see 740 (red) - 400 (blue) nm • Plant pigments absorb light in different wavelengths like our eyes • Chlorophyll a and b = absorb red/orange and blue/violet • Thus they reflect green light, which is why plants are green
There are other plant pigments in smaller amounts. In the fall, the chlorophylls break down first, leaving other pigments that reflect more orange and red light.
The most effective portion(s) of the visible spectrum in driving photosynthesis is (are): A) the violet-blue portion.B) the yellow-green portion.C) the red-orange portion.D) Both a) and b) are correct.E) Both a) and c) are correct.
Built up potential energy When released = kinetic energy which can be used to form ATP
Where does the Calvin cycle take place? A) in the stroma of the chloroplastB) in the thylakoid membraneC) in the Hobbesian membraneD) in the cellular cytoplasmE) around the chlorophyll molecule
Which of the following is NOT a product of photosynthesis? A) glucose B) Oxygen C) Sugars D) carbon dioxide E) None of the above; all are products of photosynthesis.
Which of the following statements about the light reactions of photosynthesis is correct? A) Pigments absorb light energy, which excites electrons. B) The energy of the sun is captured as potential energy. C) Water molecules split, providing a source of electrons. D) Only a) and c) are correct. E) a), b), and c) are all correct.
Bubbles come from the leaves of an Elodea plant when it is put under water because: A) oxygen and carbon dioxide diffuse out of vacuoles when vacuole pressure is reduced. B) thylakoids become depressurized and release nitrogen gas. C) oxygen is a by-product of photosynthesis. D) the cell wall is permeable to the gases released by the stomata. E) due to anaerobic conditions underwater, the plant must resort to fermentation, causing the production of excess carbon dioxide.
Photosynthesizing plants rely on water: A) to replace electrons that are excited by light energy and passed from molecule to molecule down an electron transport chain. B) to serve as a high-energy electron carrier. C) to concentrate the beams of light hitting a leaf, focusing them on the reaction center. D) to provide the protons necessary to produce chlorophyll. E) to replenish oxygen molecules that are lost during photosynthesis.
The most abundant protein in the world is the enzyme that initiates the fixation of carbon in the Calvin cycle. This enzyme is called: A) rubisco.B) ribulosebiphosphate.C) ATP-synthase.D) glyceraldehyde-3-phosphate.E) crassulacean acid.
Openings in leaves for gas exchange – what gases? Pleural form = stomata
The carbon dioxide needed for photosynthesis enters the plant through the: A) stroma.B) stomata.C) grana.D) thylakoid.E) roots.
Shape of leaf and Photosynthesis • Leaves have evolved to maximize photosynthesis while minimizing water loss • Broad surface oriented toward sunlight • Small stomata regulating air intake and transpiration
Which is why plants from different ecosystem communities can have very different leaves • Plants compete for sunlight, so some leaf modifications help a plant climb to sunlight
Low light conditions • Large leaves of tropical forest floor plants • Collect as much light as possible
Pine trees can photosynthesize in winter due to compounds in sap that act as antifreeze. • Pine trees can lose up to 26 gallons of water on a sunny, hot day. Under dry conditions, they lose less water than other types of trees • 1) pine needle has small surface area, • 2) leaves (needles) have a waxy cuticle layer and • 3) stomata are recessed into the needle surface, so somewhat protected from the wind so less evaporation.
Cell Respiration • All organisms need a form of energy • Cell metabolism • Muscle action • Eliminating waste • Reproduction • Growth of tissues, development • Behavior • Not all use oxygen, but eukaryotes do
Cellular respiration is the process by which: A) oxygen is produced during metabolic activity.B) light energy is converted into kinetic energy.C) oxygen is used to transport chemical energy throughout the body.D) energy from the chemical bonds of food molecules is captured by an organism.E) ATP molecules are converted into water and sugar.
Glyco = sugar Lysis = splitting
Aerobic Respiration 1. Krebs Cycle 2. Electron transport phosphorylation or chain
Electron Transport Chain= Oxygen used to accept H+ plus electrons to form water & large amounts of ATP
32 ATP from 1 sugar molecule! Total: 2 from glycolysis, 2 from Krebs Cycle + 32 from ETC = 36 ATP net gain