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Plants and some other types of organisms are able to use light energy from the sun to convert H 2 0 & CO 2 into glucose. 2. Organisms such as plants, algae & some bacteria which make their own food from light energy, are called autotrophs. Autotrophs.
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Plants and some other types of organisms are able to use light energy from the sun to convert H20 & CO2 • into glucose. • 2. Organisms such as plants, algae & some bacteria which make their own food from light energy, are called autotrophs.
Photosynthesis occurs within the chloroplasts of plant cells. The green pigment that captures the sun’s energy is chlorophyll.
What is the equation for the chemical reaction of photosynthesis?
Photosynthesis Equation • Plants take in inorganic compounds • (water, carbon dioxide) • 2.In the presence of light energy they will convert the inorganic compounds to an organic compound (glucose) • enzymes • 6 Water + 6 Carbon dioxide Glucose + 6 Oxygen
Regents Practice Question # 1 The diagram below represents a process that occurs in a structure of a specialized cell? Which row in the chart correctly identifies the letters in the diagram?
Regents Practice Question # 2 Scientists studying ocean organisms are discovering new and unusual species. Which observation could be used to determine that an ocean organism carries out autotrophic nutrition? (1) Chloroplasts are visible inside the cells. (2) Digestive organs are visible upon dissection. (3) The organism lives close to the surface. (4) The organism synthesizes enzymes to digest food
Regents Practice Question # 2 (Answer) Scientists studying ocean organisms are discovering new and unusual species. Which observation could be used to determine that an ocean organism carries out autotrophic nutrition? (1) Chloroplasts are visible inside the cells. (2) Digestive organs are visible upon dissection. (3) The organism lives close to the surface. (4) The organism synthesizes enzymes to digest food
What happens during photosynthesis? • Carbon dioxide enters the leaf through holes called stomata. It is a tiny opening or pore, found mostly on the undersurface of a plant leaf, and used for gas exchange.
Stomata and Guard Cells • They are located on the underside of the leaves. • In the presence of sunlight, the guard cells swell and this causes the stoma to open up. • CO2 gas moves into the leaf and water vapor diffuses from the leaf. • In dark conditions, the guard cells do not swell and the stoma remain closed and photosynthesis does not take place.
What happens during photosynthesis? • Water is brought up through the roots to the leaves • Some of the Glucose is used right away by the plant for energy; some is stored as starch; and some is built into plant tissue. • Oxygen is released into the environment.
Factors Influencing Photosynthesis • Temperature • It should be between 0° – 35° C due to the need for enzyme activity. • 2.Light Intensity • Some plants need more light. • 3.Water Availability • Some plants need more water.
Regents Practice Question #3 In some land plants, guard cells are found only on the lower surfaces of the leaves. In some water plants, guard cells are found only on the upper surfaces of the leaves. Explain how guard cells in both land and water plants help maintain homeostasis. In your answer be sure to: • identify one function regulated by the guard cells in leaves [1] • explain how guard cells carry out this function [1] • give one possible evolutionary advantage of the position of the guard cells on the leaves of land plants [1]
Regents Practice Question #3 (Answers) • Control the entrance of gases into and out of the leaves of the plant. • Depending on the amount of light present, the guard cells will swell or contract causing the stomata to either open or close. • If the guard cells were located on top of the leaves they would remain open most of the time and the plant might dehydrate because the water vapor would constantly be leaving the plant.
Regents Practice Question #4 A student performed an experiment to demonstrate that a plant needs chlorophyll for photosynthesis. He used plants that had green leaves with white areas. After exposing the plants to sunlight, he removed a leaf from each plant and processed the leaves to remove the chlorophyll. He then tested each leaf for the presence of starch. Starch was found in the area of the leaf that was green, and no starch was found in the area of the leaf that was white. He concluded that chlorophyll is necessary for photosynthesis. Which statement represents an assumption the student had to make in order to draw this conclusion? (1) Starch is synthesized from the glucose produced in the green areas of the leaf. (2) Starch is converted to chlorophyll in the green areas of the leaf. (3) The white areas of the leaf do not have cells. (4) The green areas of the leaf are heterotrophic
Regents Practice Question #4 A student performed an experiment to demonstrate that a plant needs chlorophyll for photosynthesis. He used plants that had green leaves with white areas. After exposing the plants to sunlight, he removed a leaf from each plant and processed the leaves to remove the chlorophyll. He then tested each leaf for the presence of starch. Starch was found in the area of the leaf that was green, and no starch was found in the area of the leaf that was white. He concluded that chlorophyll is necessary for photosynthesis. Which statement represents an assumption the student had to make in order to draw this conclusion? (1) Starch is synthesized from the glucose produced in the green areas of the leaf. (2) Starch is converted to chlorophyll in the green areas of the leaf. (3) The white areas of the leaf do not have cells. (4) The green areas of the leaf are heterotrophic
Regents Practice Question 5 & 6 A small water plant (elodea) was placed in bright sunlight for five hours as indicated below. Bubbles of oxygen gas were observed being released from the plant. Since oxygen gas is being released, it can be inferred that the plant is (1) producing glucose (2) making protein (3) releasing energy from water (4) carrying on active transport What substance did the plant most likely absorb from the water for the process that produces the oxygen gas? (1) dissolved nitrogen (2) carbon dioxide (3) an enzyme (4) a hormone
Regents Practice Question 5 & 6 (Answer) A small water plant (elodea) was placed in bright sunlight for five hours as indicated below. Bubbles of oxygen gas were observed being released from the plant. Since oxygen gas is being released, it can be inferred that the plant is (1) producing glucose (2) making protein (3) releasing energy from water (4) carrying on active transport What substance did the plant most likely absorb from the water for the process that produces the oxygen gas? (1) dissolved nitrogen (2) carbon dioxide (3) an enzyme (4) a hormone
Regents Practice Question #7 For the process of autotrophic nutrition, the arrow labeled A would most likely represent the direction of movement of (1) carbon dioxide, water, and solar energy (2) oxygen, glucose, and solar energy (3) carbon dioxide, oxygen, and heat energy (4) glucose, water, and heat energy
Regents Practice Question #7 (Answer) For the process of autotrophic nutrition, the arrow labeled A would most likely represent the direction of movement of (1) carbon dioxide, water, and solar energy (2) oxygen, glucose, and solar energy (3) carbon dioxide, oxygen, and heat energy (4) glucose, water, and heat energy
Regents Practice Question # 8 Which statement best describes the starch content of two leaves taken from the same plant shown in the chart below? (1) Neither leaf contains starch. (2) Both leaves contain same amount of starch. (3) Leaf A contains more starch than leaf B. (4) Leaf B contains more starch than leaf A.
Regents Practice Question # 8 (Answer) Which statement best describes the starch content of two leaves taken from the same plant shown in the chart below? (1) Neither leaf contains starch. (2) Both leaves contain same amount of starch. (3) Leaf A contains more starch than leaf B. (4) Leaf B contains more starch than leaf A.
What is Cellular Respiration? • It is a process that is opposite to the process of photosynthesis. • Photosynthesis is a process that stores up energy and cellular respiration is a process that allows that stored up energy to be released for use by the cells • The release of chemical energy for use by cells is called cellular respiration.
What is the chemical equation for cellular respiration? The chemical equation for Cellular Respiration is: C6H12O6 + 6O26CO2 + 6H2O + ATP Energy Glucose Oxygen Carbon Water Dioxide
When and where does Cellular Respiration Occur? • All Eukaryotic cells and most Prokaryotic Cells. • 24 hours a day, 7days a week, 365 days a year • In other words, it is going on constantly because cells are alive and have a constant need for energy.
What is ATP Energy ? • A Glucose molecule has too much energy for a cell to release and use all at one time. • (Think of it as a $100 bill) • Glucose actually gets broken down into a much smaller molecule called ATP. • (Think of ATP as a $1 bill) • One glucose molecule breaks down into about 90 ATP molecules. • ATP is the chemical fuel that a cell is able to handle, it is called Adenosine Triphosphate.
Regents Practice Question # 9 The diagram below represents a plant cell. Which process takes place in structure A? (1) cellular respiration (2) heterotrophic nutrition (3) digestion of fats (4) protein synthesis
Regents Practice Question # 9 (Answer) The diagram below represents a plant cell. Which process takes place in structure A? (1) cellular respiration (2) heterotrophic nutrition (3) digestion of fats (4) protein synthesis
Regents Practice Question # 10 Much of the carbon dioxide produced by green plants is not excreted as a metabolic waste because it (1) can be used for photosynthesis (2) is too large to pass through cell membranes (3) is needed for cellular respiration (4) can be used for the synthesis of proteins
Regents Practice Question # 10 (Answer) Much of the carbon dioxide produced by green plants is not excreted as a metabolic waste because it (1) can be used for photosynthesis (2) is too large to pass through cell membranes (3) is needed for cellular respiration (4) can be used for the synthesis of proteins
Regents Practice Question # 11 The diagram below represents a biochemical process. Which molecule is represented by X? (1) DNA (2) protein (3) starch (4) ATP
Regents Practice Question #11(Answer) The diagram below represents a biochemical process. Which molecule is represented by X? (1) DNA (2) protein (3) starch (4) ATP
Regents Practice Question # 12 In what way are photosynthesis and cellular respiration similar? (1) They both occur in chloroplasts. (2) They both require sunlight. (3) They both involve organic and inorganic molecules. (4) They both require oxygen and produce carbon dioxide
Regents Practice Question # 12 (Answer) In what way are photosynthesis and cellular respiration similar? (1) They both occur in chloroplasts. (2) They both require sunlight. (3) They both involve organic and inorganic molecules. (4) They both require oxygen and produce carbon dioxide
Regents Practice Question # 13 . The diagram below represents a cell found in some complex organisms. The enlarged section represents an organelle, labeled X, found in this cell. Describe the function of organelle X and explain how it is important to the survival of the cell. In your answer, be sure to: • identify organelle X [1] • state the process that this organelle performs [1] • identify the two raw materials that are needed for this process to occur [1] • identify one molecule produced by this organelle and explain why it is important to the organism [2]
Regents Practice Question # 13 (Answer) • Organelle x is the mitochondria • It is the site for cellular respiration to take place. • Glucose and Oxygen are the raw materials. • ATP is a molecule that is produced from cellular respiration. It is important because it is the fuel for the cell.