Millie Tunnell Exam 3 Study guide FALL 2013 Photosynthesis 1 What is Eutrophication What causes overgrowth of algae Be able to explain the chain of events that lead to a dead zone What is a dead zone Eutrophication is the name of the entire process Excess nutrients cause overgrowth of algae that are dumped into the water Dead zones end up having low oxygen concentrations they cannot support fish or other creatures and they are a result from pollution heterotrophs have an increase in food source so they bloom a lot and use all the oxygen and when that oxygen is low there is a dead zone a Nutrients pollution get dumped into water b algae cyanobacteria bloom to massive number c Heterotrophs blood and they feed on autotrophs consumes O2 via respiration d O2 level plummet 2 What is the overall equation of photosynthesis CO2 H2O glucose O2 3 What are autotrophs producers Heterotrophs consumers Autotrophs are producers and they are living things that are able to make their own food without using organic molecules derived from any other living thing Heterotrophs eat autotrophs because they can t make their own food 4 What types of organisms are capable of photosynthesis All plants algae cyanobacteria 5 What are chloroplasts What pigments are found in the chloroplasts They are the major sites of photosynthesis in green plants Chlorophyll is located in chloroplasts which is an important light absorbing pigment in chloroplasts is responsible for the green color of plants and plays a central role in converting solar energy to chemical energy 6 What are stomata Why must they be open during photosynthesis What gasses are exchanged through these pores Stomata are little holes that oxygen can go out of used to control gas exchange They must be open during photosynthesis because let CO2 in have to be open for gas exchange to occur Co2 and O2 pass through these pores 7 Why are plants green What color s of the visible light spectrum is are reflected by chlorophyll What color s is are absorbed Chlorophyll is responsible for the green color of plants The color pigments do not absorb however they reflect off and that is how we see them as the color of the wavelengths that are transmitted and chlorophyll transmits green chlorophyll absorbs all of the other colors 8 Why do leaves turn red yellow and orange in the fall What are carotenoids By the fall the chlorophyll has all been recycled and first the cells notice how the days are becoming shorter and the length and so when it becomes shorter it draws nutrients out and first the chlorophyll is all drawn out then carotenoids are left for a while before they die Carotenoids are excessive pigments like yellow and reds and it s when those colors are reflected they absorb everything 9 What happens to electrons when pigments absorb sunlight energy Where do the electrons go How is this used to generate ATP What process replaces the lost electrons to the first pigment cluster When pigments absorb sunlight energy the molecules absorbs and reflects light specifically chlorophyll The electrons become excited and the electrons jump on the electron transport chain and are used to generate ATP These excited electrons are used to generate an energy carrying molecule known as ATP this is used on the synthesis part of photosynthesis to make sugar The transport chain members pump hydrogen The splitting of water replaces the lost electrons to the first pigment cluster 10 What are the two important products of the light reactions Where do these products go What cycle actually makes the glucose product Where does CO2 come from The two important products is ATP and electrons these products go to dark reactions important for plants The O2 goes back to the air and is put to waste while the ATP goes to the next phase for the carbon reactions The dark reactions makes the glucose product from CO2 or the carbon synthesis reactions Co2 comes from the atmosphere 11 What is global warming and the greenhouse effect How it is that photosynthesis is said to moderate the effect of global warming Increasing concentrations of greenhouse gases lead to global warming a slow but steady rise in Earth s surface temperature the rise in CO2 is due to the combustion of carbon based fossil fuels Greenhouse effect built up CO2 when carrying out photosynthesis it eliminates CO2 can help with problem the greenhouse effect results from solar energy warming our planet CO2 in atmosphere acts like greenhouse doesn t let back out and reflect heat back to Earth keeping the planet warm and supporting life planet slowly warming As we increase the level of greenhouse gases Earth s temperature rises above normal initiating problems DNA and Viruses DNA RNA protein 1 Are viruses alive Why or why not What is their structure like What is a capsid What is a viral envelope No viruses are not alive because they are not cellular cant reproduce they must find a host cell entering a host cell is how they reproduce they can t take in and process energy no response to the environment a capsid is an infectious particle enclosed in protein coat The simplest viruses has nucleic acid DNA RNA genetic info surrounded by a coat and some has double layer envelope a phospholipid membrane 2 How do viruses take over control of the host cell Why can viruses only infect certain host cells What must happen in order for a virus to attach to a host cell Getting genetic material into the host cell Viruses take over the cells by hijacking a host cell by infecting the cell with a copy of their DNA or RNA which tells the cell more viruses It must be on surfaces they can bind to has to be very specific Receptors must be able to bind 3 What is the lytic cycle Lysogenic cycle Which one does a latent virus use slide 12 In the lytic cell the virus is active and the phages are released Lysogenic cell inserts itself in the host chromosome can be there for unknown periods of time bacteria doesn t know it is infected the virus can be latent for a while hides 4 What is a retrovirus Why do we call HIV that What is reverse Transcriptase Be familiar with the life cycle of HIV A retro virus is Virus that has RNA for genetic material reverse inscribed to DNA also an RNA virus which is backwards from DNA viruses which goes RNA DNA mRNA protein it is an enveloped virus which can enter the cell a different way because of the envelope HIV has RNA as its geno when enters cells its reversed RNA is reversetranscribed to DNA Reverse transcriptase is an enzyme