Lecture 13Outline of Last Lecture I. Krebs CycleII. Oxidative PhosphorylationIII. Summary of Cellular RespirationIV. FermentationOutline of Current Lecture I. PhotosynthesisII. PlantsIII. How It WorksIV. The Circle of LifeV. Cell CycleCurrent LectureI. Photosynthesisa. Opposite of respiration in regards to equation and energyb. Major goal of respiration is to convert stable chemical energy into readily available usable form (ATP)c. Major goal is to convert light energy to into stable chemical energy (make food)d. Processes have much in commone. All living things depend on photosynthesisf. Bottom of the food chain relies on photosynthesis to make own foodg. Autotrophs  self-feeders, make their own foodh. Heterotrophs  cannot produce own food, rely on food produced by other living things, “consumers”II. Plantsa. Photoautotrophs  make their own food with photosynthesisb. ALSO do respirationc. Animals can only do oneIII. How it worksa. Starts in chloroplastb. Has 3 layers of membranes:i. Thylakoid  thylakoid spaceii. Inneriii. Outerc. Occurs in two stages:i. Calvin Cycle1. Uses CO2 to make sugar (anabolic pathway)2. ATP and electrons for the Calvin cycle are produced during the light reactions3. CO2 enters stroma + RuBP (5 carbon molecule)  catalyzed by rubisco = 3 phosphoglycerates4. 3 phosphoglycerates + ATP + electrons = sugar5. anabolic pathway, and reduction ii. Light Reaction1. Light energy makes ATP and a reduced coenzyme BIOL 1st Edition2. Occurs on thylakoid membranes of chloroplast3. Uses 2 photosystems  light harvesting units on the thylakoid membranes (connected by electron transport chain)4. PSIIa. Knocks electrons off pigment molecules  gets passed down chain  protons get transferred to thylakoid space  oxygen5. PSIa. Knocks electron off  final electron acceptor is oxidized form of NADP+  reduced coenzymed. ATP is produced by chemiosmosise. The photosynthetic ATP synthase is on the thylakoid membrane and produces ATP in the stromaIV. The Circle of Lifea. Connection between respiration and photosynthesisb. Products of one are the reactant of the otherc. Chain reaction  everything would die if these diedV. Cell Cyclea. All cells are made from cells and come from other cellsb. Parent cell divides to produce an identical daughter cellc. Complex process in which passes an identical copy of all DNA to each daughter celld. 2 Stages:i. Accurate replication of DNAii. Allocation of one of the identical copies to each new daughter celle. Cell reproduction  Cell divisioni. Single celled organisms reproduce the whole organismii. Multicellular organisms is used for growth and tissue repairf. Genome  cell’s total genetic informationi. One or more long DNA moleculesii. Genes are arranged along the DNA, hundreds to thousands of genes for DNA moleculeiii. Each gene has the code for how to make a proteiniv. Proteins determine what an organism is and what it can dog. DNA is arranged as chromosomes i. DNA molecule with associated proteins to help maintain structure and control the activity of the genesii. Chromosomes take different forms  these are given different names1. Chromatin – mass of dispensed DNA plus proteins found in between periods of cell division 2. Replicated chromosome – when the DNA molecules replicate (an exact copy) the two copies remain held together along the length by proteins called “cohesins” and take on acondensed form (shorter and thicker) a. Each DNA molecule is called a sister chromatid and the 2 sister chromatids of a replicated chromosome are more rightly held together at a region called the