AP Biology Review Session 2

Transcription

1 AP Biology Review Session 2 The cell is sometimes described as a protein factory. Using the cell-as-factory analogy, which of the following accurately describes the functions of the endomembrane system? The three domains of life described by biologists today include the bacteria, the archaea and the eukarya (all other forms of life). What is the principle difference between the eukarya or eukaryotes and the prokaryotes (archaea and bacteria)? The prokaryotes do not have a plasma membrane surrounding the cell. The prokaryotes use RNA and not DNA to pass on the genetic message. The eukaryotes have the interior of the cell divided by internal membranes into specialized compartments. The eukaryotes engage in cellular metabolism while the prokaryotes do not. A is an example of a unicellular organism. a. cat b. pine tree c. fish d. protist Bacterial cells are prokaryotic. Unlike a typical eukaryotic cell, they. a. lack a nucleus b. have a smaller nucleus c. lack a plasma membrane d. Have more internal membranous compartments are the major lipids of plasma membranes. a. Triglycerides b. Phospholipids c. Fatty acids d. Steroids Which of these pairs of organelles are responsible for energy conversion? a. mitochondrion and chloroplast b. vacuole and ribosome c. centriole and lysosome

2 d. Golgi apparatus and smooth endoplasmic reticulum Information is transferred from the cell nucleus to ribosomes via the molecule. a. RNA b. rer c. ser d. DNA 1. Describe microscopes and their importance in viewing cellular structure 2. Distinguish between prokaryotic and eukaryotic cells 3. Describe the structure of cell membranes and how membrane structure relates to function 4. Discuss ways that cellular organelles are involved in the manufacture and breakdown of important cellular molecules 5. List cell structures involved in manufacture and breakdown of important cellular materials 6. Describe the function of each cellular organelle that is involved in manufacture and breakdown of important cellular materials 7. List cell structures involved in energy conversion 8. Describe the function of each cellular organelle that is involved in energy conversion 9. List cell structures involved in internal and external support of cells 10. Describe the function of each cellular organelle that is involved in internal and external support of the cell This diagram represents osmosis of water across a semipermeable membrane. The U-tube on the right shows the results of the osmosis. What could you do to level the solutions in the two sides of the right hand U-tube? Add more water to the left hand side. Add more water to the right hand side. Add more solute to the left hand side. Add more solute to the right hand side. Membranes organize cell activities. The proteins imbedded in the membranes are essential to their function. These membrane proteins have properties that allow them to float in the membrane. Which of the following describe those properties? The surface region of the protein in the interior of the membrane is mostly hydrophobic. The surface region of the protein in the interior of the membrane is mostly hydrophillic.

3 The surface region exposed to the outer environment is hydrophobic. The surface region exposed to the interior environment is hydrophobic. Enzymes catalyze the many reactions in a cell. There are hundreds of different enzymes in a cell each with a unique three-dimensional shape. Why do cells have so many different enzymes? Each enzyme molecule can only be used once. The shape of enzyme s active site generally fits a specific substrate. The substrate molecules react with enzymes to create new enzymes. Enzymes are randomly produced. With thousands of different shapes one is likely to work. Which of the following is a measure of disorder? a. entropy b. kinetic energy c. potential energy d. respiration A(n) is the amount of energy that raises the temperature of 1 g of water by 1 C. a. calorie b. ATP c. entropy d. enzyme Molecules of food and gasoline contain a special form of potential energy called energy, due to the arrangement of their atoms. a. kinetic b. ionic c. covalent d. chemical Enzymes increase the rate of a reaction by. a. decreasing activation energy b. changing the ph

4 c. increasing the temperature of the substances d. contributing water to the reaction Osmosis is. a. the diffusion of nonpolar materials b. the diffusion of water across a semi-permeable membrane c. the diffusion of a solute d. active transport 1. Describe the cell membrane within the context of the fluid mosaic model 2. Explain how spontaneous formation of a membrane could have been important in the origin of life 3. Describe the passage of materials across a membrane with no energy expenditure 4. Explain how osmosis plays a role in maintenance of a cell 5. Explain how an imbalance in water between the cell and its environment affects the cell 6. Describe membrane proteins that facilitate transport of materials across the cell membrane without expenditure of energy 7. Discuss how energy-requiring transport proteins move substances across the cell membrane 8. Distinguish between exocytosis and endocytosis and list similarities between the two 9. Explain how energy is transformed during life processes 10. Define the two laws of thermodynamics and explain how they relate to biological systems 11. Explain how a chemical reaction can either release energy or store energy 12. Describe ATP and explain why it is considered to be the energy currency of a cell 13. Define enzyme and explain how enzymes cause a chemical reaction to speed up 14. Discuss the specificity of enzymes 15. Distinguish between competitive inhibitors and noncompetitive inhibitors Some prokaryotic and all eukaryotic cells use oxygen to harvest energy from food molecules? In what form is that energy available to power cell work? Heat and light. Glucose molecules.

5 Fat molecules. ATP molecules. Fat molecules store 9 Kcal per gram. There are about 454 grams in a pound of fat so that means that one pound of fat stores about 4,000 Kcal of energy. Based on the chart of energy consumption, which of the following would burn off a pound of fat, assuming your normal activities consumed calories equal to the rate of your calorie intake? Running 7 miles Swimming 2 miles Walking 27 miles Running about 40 miles The figure above represents an overview of the different processes of cellular respiration. Which of the following correctly identifies the different processes? 1. Glycolysis; 2. Electron transport chain; 3. Krebs cycle 1. Glycolysis; 2. Krebs cycle; 3. Electron transport chain 1. Krebs cycle; 2. Electron transport chain; 3. Glycolysis 1. Electron transport chain; 2. Glycolysis; 3. Krebs cycle The electron transport chain is too deeply embedded in the mitochondria. The electron transport chain only receives electrons carried by reduced electron carrier molecules such as NADH. The electron transport chain only receives electrons carried by oxidized electron carrier molecules such as NAD+. The electron transport chain does not produce ATP. The molecule is the main source of energy used to drive chemical reactions in cells. a. lactic acid b. ATP c. carbon dioxide d. DNA is the anaerobic harvest of food energy. a. Electron transport b. Cellular respiration

6 c. Photosynthesis d. Fermentation Where in the cell does glycolysis occur? a. outside the mitochondria b. in the endoplasmic reticulum c. in the fluid of the mitochondria d. on the outer mitochondrial membrane The final electron acceptor of aerobic respiration is. a. ATP b. oxygen c. carbon dioxide d. lactic acid What must pyruvic acid be converted to before it can enter the citric acid cycle? a. acetyl CoA b. lactic acid c. ethyl alcohol d. NADH 1. Explain how photosynthesis and cellular respiration are necessary to provide energy that is required to sustain your life 2. Explain why breathing is necessary to support cellular respiration 3. Describe how cellular respiration produces energy that can be stored in ATP 4. Explain why ATP is required for human activities 5. Describe the process of energy production from movement of electrons 6. List and describe the three main stages of cellular respiration 7. Describe the major steps of glycolysis and explain why glycolysis is considered to be a metabolic pathway 8. Explain how pyruvate is altered to enter the citric acid cycle and why coenzymes are important to the process 9. Describe the citric acid cycle as a metabolic pathway designed for generating additional energy from glucose

7 10. Discuss the importance of oxidative phosphorylation in producing ATP 11. Describe useful applications of poisons that interrupt critical steps in cellular respiration 12. Review the steps in oxidation of a glucose molecule aerobically 13. Compare respiration and fermentation 14. Provide evidence that glycolysis evolved early in the history of life on Earth 15. Provide criteria that a molecule must possess to be considered a fuel for cellular respiration 16. Discuss the mechanisms that cells use to biosynthesize cell components from food This is the summary equation for the process of photosynthesis. This reaction is endergonic. is exergonic. has an equal amount of energy in the reactants and the products. is catabolic. Both cellular respiration and photosynthesis rely on electron transport chains embedded in membranes to produce ATP molecules. Which of the following correctly describes the difference between the two types of electron transport chains? In cellular respiration the electron source is water and the final electron destination is oxygen. In cellular respiration the electron source is the hydrogens in energy rich food and the final electron destination is oxygen. In photosynthesis the electron source is water and the final destination is oxygen. Both 2 and 3. When a photon of the correct energy is absorbed by a photosystem, an electron is energized and transferred to a primary electron acceptor. This creates an electron hole. How is the missing electron replaced? Electrons removed from glucose replace the missing electrons. Electrons from hydrogen made available by splitting water replace the missing electrons. Imagine that you have planted bean seedlings (C 3) and corn seedlings (C 4) in an artificial soil and sealed them in an aquarium. The aquarium has plenty of light, nutrients and water but a given volume of air. Based on your knowledge of photorespiration which of the following are most likely? Both kinds of plants should do equally well.

8 As the plants photosynthesize the carbon dioxide levels will fall giving the C 3 plants the advantage. As the plants photosynthesize the carbon dioxide levels will fall giving the C 4 plants the advantage. The results are unpredictable. Which of the following is an autotroph? a. mushroom b. honeybee c. mountain lion d. pine tree In which organelle does photosynthesis occur? a. chloroplast b. mitochondrion c. nucleus d. smooth endoplasmic reticulum is the source of the oxygen gas released by a photosystem. a. NADPH b. Water c. Carbon dioxide d. Chlorophyll a The light reactions of photosynthesis take place in the. a. stroma b. thylakoid membrane c. cytosol d. cristae, produced during the Calvin cycle, is the raw material plants use to make necessary organic molecules. a. Glucose b. Carbon dioxide

9 c. Sucrose d. G3P You should now be able to 1. Explain the value of autotrophs as producers 2. Provide a general description of photosynthesis in chloroplasts 3. Explain how plants are able to produce oxygen as a product of photosynthesis 4. Contrast photosynthesis to respiration in terms of redox reactions 5. Describe the importance of visible radiation to photosynthesis 6. Describe plant photosystems and their function in photosynthesis 7. Describe the linkage (connection) between the two plant photosystems 8. Describe how chemiosmosis powers ATP synthesis in plants 9. Discuss the Calvin cycle and how it uses ATP and NADPH 10. Describe two plant adaptations that save water in hot, dry climates 11. Detail how photosynthesis could help moderate globing warming 12. Discuss the importance of the Earth s protective ozone layer