It accepts and holds two high energy electrons along with a H+ (hydrogen ion) and transfers them to chemical reactions in the cell that need energy.
An Overview of Photosynthesis
Photosynthesis uses the energy of sunlight to convert water and carbon dioxide (reactants) into high energy sugars and oxygen (products).
Plants then use the sugars to make starches and provide energy for other making other compounds.
You Should Know
What role do pigments play in the process of photosynthesis?
What are electron carrier molecules?
What are the reactants and products of photosynthesis?
Chloroplasts are the organelles where photosynthesis takes place.
Chloroplasts contain stacks of photosynthetic membranes called thylakoids; they are interconnected and arranged in stacks called grana.
Chlorophyll is also located in the thylakoids.
The fluid portion of the chloroplast outside the thylakoids is the stroma.
Because light is energy, any compound that absorbs light absorbs energy.
Chlorophyll absorbs visible light particularly well.
A large amount of that energy is transferred to electrons; high energy electrons are produced.
In this activity, students first learn about the structure and functions of starch and protein and the basics of how starch, amino acids and proteins are synthesized. Then, students learn about scientific investigation by carrying out key components of the scientific method, including developing experimental methods, generating hypotheses, designing and carrying out experiments to test these hypotheses and, if appropriate, using experimental results to revise the hypotheses. Students carry out two experiments which test whether starch and protein are found in some or all foods derived from animals or plants or both. (NGSS)
In this analysis and discussion activity, students learn how the structure of cells, organs and organ systems is related to their functions. (Structure includes shape, constituent components, and relationships between components.) Students analyze multiple examples of the relationship between structure and function in diverse eukaryotic cells and in the digestive system. Students also learn that cells are dynamic structures with constant activity, and they learn how body systems interact to accomplish important functions. (NGSS)
This analysis and discussion activity reviews how eukaryotic cells are molecular factories in two senses: cells produce molecules and cells are made up of molecules. The questions guide students to think about how the different parts of a eukaryotic cell cooperate to function as a protein-producing factory and as a recycling plant. Additional questions require students to identify the locations and functions of different types of molecules in eukaryotic cells.
In this analysis and discussion activity, students learn how the function of molecules and cells is related to their structure (including shape, constituent components, and relationships between components). Students analyze multiple examples of the relationship between structure and function in diverse proteins and eukaryotic cells. In addition, students learn that cells are dynamic structures with constant activity, students learn about emergent properties, and students engage in argument from evidence to evaluate three alternative claims concerning the relationship between structure and function. (NGSS)
In this analysis and discussion activity, students develop their understanding of photosynthesis by answering questions about three different models of photosynthesis. These models are a chemical equation, a flowchart that shows changes in energy and matter, and a diagram that shows the basic processes in a chloroplast. Students learn about the role of scientific models by evaluating the advantages of each of these models for understanding the process of photosynthesis. (NGSS)
In the first part of this activity, students learn how to use the floating leaf disk method to measure the rate of net photosynthesis (i.e. the rate of photosynthesis minus the rate of cellular respiration). They use this method to show that net photosynthesis occurs in leaf disks in a solution of sodium bicarbonate, but not in water. Questions guide students in reviewing the relevant biology and analyzing and interpreting their results. In the second part of this activity, student groups develop hypotheses about factors that influence the rate of net photosynthesis, and then each student group designs and carries out an investigation to test the effects of one of these factors. (NGSS)
Students analyze evidence to evaluate four hypotheses about where a plant’s mass comes from. For example, students analyze Helmont’s classic experiment, and evaluate whether his interpretation was supported by his evidence. Thus, students engage in scientific practices as they learn that plants consist mainly of water and organic molecules and most of the mass of organic molecules consists of carbon and oxygen atoms originally contained in carbon dioxide molecules from the air. (NGSS)
This multi-part minds-on, hands-on activity helps students to understand both alcoholic fermentation and the engineering design process. In the first two parts of this activity, students learn about alcoholic fermentation and test for alcoholic fermentation by assessing CO2 production by live yeast cells in sugar water vs. two controls. The third part of this activity presents the bioengineering design challenge where students work to find the optimum sucrose concentration and temperature to maximize rapid CO2 production. Structured questions guide the students through the basic engineering steps of applying the relevant scientific background to the design problem, developing and systematically testing proposed design solutions, and then using initial results to develop and test improved design solutions. (NGSS)
This overview presents key concepts that students often do not learn from standard textbook presentations and suggests a sequence of learning activities to help students understand how the parts of a cell work together to accomplish the multiple functions of a dynamic living cell. Suggested activities also reinforce student understanding of the relationships between molecules, organelles and cells, the diversity of cell structure and function, and the importance and limitations of diffusion. This overview provides links to web resources, hands-on activities, and discussion activities.
In this hands-on, minds-on activity students use model chromosomes and answer analysis and discussion questions to learn how mitosis ensures that each new cell gets a complete set of genes. Students also learn how genes on chromosomes influence phenotypic characteristics and how a single cell develops into the trillions of cells in a human body. This activity can be used to introduce mitosis or to reinforce student understanding of mitosis. (NGSS)
Students use model chromosomes and answer analysis and discussion questions to learn how each person inherits one copy of each gene from each of his/her parents. As they model meiosis and fertilization, students follow the alleles of three human genes from the parents' body cells through gametes to zygotes. In this way, students learn how genes are transmitted from parents to offspring through the processes of meiosis and fertilization. Students analyze the results of crossing over, independent assortment and fertilization to learn how meiosis and fertilization contribute to genetic and phenotypic variation. Students also compare and contrast mitosis and meiosis, and they learn how a mistake in meiosis can result in Down syndrome or death of an embryo. This activity can be used to introduce meiosis and fertilization or to review these processes. (NGSS)