1. Define and give an example of the following:

Transcription

1 Name: KEY Date: / / HR: Section 1 Chemistry of Life CHAPTER 3 CELL PROCESSES REVIEW 1. Define and give an example of the following: a. Atoms invisible particles that make up all mater; made from protons, neutrons and electrons; Example: An oxygen atom has 8 protons and 8 electrons b. Compound made up of two or more elements; Example: water, sugar, carbon dioxide, sodium chloride c. Element made up of only one kind of atom; Example: gold, oxygen, carbon, sodium d. Molecule the smallest part of a molecular compound; Example: one water molecule is made of two hydrogen atoms and one oxygen atom e. Ions Electrically charged atoms; Example: sodium loses an electron to become positively charged and chlorine gains an electron to become negatively charged f. Ionic compounds occur when oppositely charged ions are attracted to each other. Example: Sodium chloride g. Mixture a combination of substances in which individual substances retain their own properties; Example: blood, sweat 2. What is an organic compound? An organic compound is one that contains carbon and hydrogen. They are usually associated with living things.

2 3. List the four types of organic compounds found in living things. Carbohydrates, lipids, proteins, nucleic acids 4. What is an inorganic compound? A compound made from elements other than carbon 5. List some examples of inorganic compounds found in humans. Water, calcium phosphate, hydrochloric acid, sodium bicarbonate, salts 6. Why is water so important for life? Water makes up more than 50% of living things; chemical reactions necessary for life take place in water; materials are transported through living things in water. 7. What are the unique characteristics of water? Surface tension, cohesion, adhesion, solid water less dense than liquid Section 2 Moving Cellular Materials 1. Compare and contrast the following sets of words: a. Passive transport, active transport They are both methods of moving materials into and out of cells through the cell membrane. Passive transport does not require energy, but active transport does require energy. Active transport requires the use of a transport protein, but only one type of passive transport uses the transport protein.

3 b. Diffusion, facilitated diffusion, osmosis All three are types of passive transport that allow materials to move through the cell membrane. They are all caused by random particle motion, which causes particles to move from areas of high concentration to low concentration to reach equilibrium. Diffusion is the movement of particles small enough to pass through the cell membrane, such as oxygen and carbon dioxide. Osmosis is the diffusion of water molecules through the cell membrane. Facilitated diffusion is the diffusion of substances, such as glucose, through a transport protein. This occurs when the substance is too large to fit through the cell membrane. c. Endocytosis, exocytosis Both processes are for moving large molecules, such as proteins or bacteria, into and out of the cell. They both involve the creation of a vesicle, using part of the cell membrane. Endocytosis is the process by which substances are taken into the cell. Exocytosis is the process by which substances leave the cell. 2. Define equilibrium. Equilibrium occurs when molecules of one substance are spread evenly throughout another substance. 3. What causes diffusion? The random motion of particles. 4. The cell membrane is selectively permeable, what does this mean? It allows some things to enter or leave the cell while keeping others inside the cell.

4 5. Explain the conditions for which each type of transport would be used in a cell. a. Diffusion Small particles such as oxygen or carbon dioxide need to enter or leave the cell in order to maintain equilibrium. b. Facilitated diffusion Larger molecules such as glucose need to enter or leave the cell (through a transport protein) to maintain equilibrium. c. Osmosis water needs to leave or enter a cell to maintain equilibrium. d. Active transport Substances need to enter or leave the cell through a transport protein and use energy to do so because it works against equilibrium. e. Exocytosis A cell needs to release certain materials that are too large to pass through the cell membrane, such as stomach cells release digestive liquids. f. Endocytosis A cell needs to take in a large material, such as a protein, that will not fit through the cell membrane. 6. A student wants to determine the effect of different liquids on grapes. He uses three grapes in three different liquids: water, grape juice and concentrated sugar water. He lets the grapes sit in the cups overnight and makes observations the next day. The grape in water has swollen and gotten bigger; the grape in juice has stayed the same; the grape in sugar water has shrunken. Explain his results.

5 Water The grape cells have taken in water through osmosis in order to maintain equilibrium. As a result, the cells swell and the grape is larger. Grape juice Water enters and leaves the cell at the same rate because the concentrations of water inside the cell and outside the cell are already at equilibrium. Sugar water Due to the high sugar content in the surrounding water, the cells lose water in order to maintain equilibrium in the cell. Therefore, the cells shrink due to water loss and the grape gets smaller. Section 3 Energy for Life 1. Define: a. Metabolism the total of all chemical reactions in an organism b. Enzyme a protein that assists in chemical reactions in an organism c. Producers Organisms that make their own food d. Consumers Organisms that do not make their own food

6 2. Fill out the following table regarding photosynthesis, respiration and fermentation. Energy (Required or Created?) Photosynthesis Respiration Fermentation Required from sunlight Creates ATP Creates ATP Occurs In Chloroplast Mitochondria Cytoplasm Reactants Things going in to cell Waste Products Things Leaving Cell Products for Cell Sunlight, carbon dioxide, water Oxygen Carbohydrates, oxygen Carbon dioxide, water Carbohydrates Lactic acid or alcohol and carbon dioxide Carbohydrates ATP ATP 3. Write the chemical equation for a. Photosynthesis Sunlight + 6 CO2 + 6 H2O C6H12O6 + 6 O2 b. Respiration C6H12O6 + 6 O2 6 CO2 + 6 H2O + ATP 4. How are photosynthesis and respiration related processes? Photosynthesis requires energy and produces the materials necessary for respiration. Respiration creates energy and produces the materials necessary for photosynthesis.

7 5. Under what conditions does fermentation occur? Fermentation occurs when cells do not have enough oxygen to undergo respiration. 6. Which cellular transport method is used for moving sugar into an animal cell? Facilitated diffusion 7. Which cellular transport method is used for moving oxygen out of a plant cell? - Diffusion