Name:_____________________________ Date:______________________ Period:____________________________ Cells and Cell Processes Common Assessment Review Questions 1. List the eight characteristics of life and give an example of each. a. DNA – all living things contain hereditary material (DNA/RNA) b. Cells / Order – living things are highly ordered starting with the basic unit of life – the cell c. Homeostasis – living things maintain a stable internal environment through regulatory activities (i.e. temperature regulation, oxygen concentration, water regulation, etc….) d. Energy – living things obtain and use energy e. Respond – living things respond to stimuli f. Growth and Develop – living things increase in size and mature over g. Reproduce – living things are capable of producing more of their own kind h. Evolve – livings things adapt to their environment 2. What is homeostasis? Give an example of it. A process by which organisms maintain a relatively stable internal environment. Examples: regulating of blood sugar levels, body temperature, water concentration, etc… 1 3. Complete the following: Cells work together to form _____tissues__________________. They work together to form _____organs__________________. They work together to form ______organ systems_____________________. And finally, they work together to form an organism. 4. Label each of the diagrams as Passive Transport or Active Transport. ____Active_____________ Transport __Passive_______________ Transport 2 5. What is the difference between passive and active transport? Passive – high concentration to low; no energy Active – low concentration to high; energy required 6. What process is taking place in the picture below? ______endocytosis (phagocytosis)_________ 7. What is the difference between eukaryotic cells and prokaryotic cells? Give an example of each. Prokaryotic cells do not have a nucleus or membrane bound organelles – bacteria. Eukarytoic cells do have a nucleus and membrane bound organelles – animal, plant, fungus, protist 8. What are specialized cells? Why aren’t unicellular organisms specialized? The structure of specialized cells allow them to perform a specific function for an organism (i.e. conducting impulses (nerve cells), contracting (muscle cells), absorption (cells lining the digestive system), etc… 9. During diffusion molecules want to move from areas of ____high ________ concentration to areas of __low__________ concentration. Water exhibits both adhesion and cohesion. What’s the difference between the two? Cohesion – water molecules are attracted to other water molecules Adhesion – water molecules are attracted to other polar molecules 10. 3 11. What is the name of the process that moves molecules of water in and out of the cell? Osmosis 12. Water is a “polar” molecule. What does that mean? Polar molecules have a charge distribution (a positively charged / electropositive end and a negatively charged / electronegative end) In water the Hydrogen atoms are slightly positive while the oxygen is slightly negative creating charged regions of the molecule. This allows it to dissolve and transport materials. 13. Use the diagram to answer the questions on the next page. a. Explain what would happen if some of the red blood cells were placed in beaker A. Water would move into the cells. The cells would swell and possibly burst. Water with very little salt is a hypotonic solution for the red blood cells. 4 b. Explain what would happen if some of the red blood cells were placed in beaker B. Water would move out of the cells. The cells would shrivel. Very salty water is a hypertonic solution for the red blood cells. c. In the human body, blood cells float in a watery liquid called plasma. Explain what would happen if some of the red blood cells were placed in beaker C. Water would move into and out of the cell at the same rate. The cell would stay the same size. Plasma is an isotonic solution for the red blood cells. d. Suppose the test tube contained plant cells instead of red blood cells. What would probably happen to the cells if they were placed in beaker A? Water would move into the cells. The cells would swell but would NOT burst due to the cell wall. e. If the test tube contained plant cells, what would probably happen to the cells if they were placed in beaker B? Water would move out of the cells. The cells membranes would pull away from the cell walls (plasmolysis) but the cells may not appear shriveled. 14. Explain, in terms of osmosis, why a raisin placed in a cup of pure water overnight will puff up with water. The concentration of water in the cup is much higher than the concentration of water in the raisin. Water will move from high concentration (cup) to low concentration (raisin) through the process of osmosis. As a result, the raisin will swell / increase in size. 15. Give at least two examples of: a. Carbohydrates – glucose (monosaccharide), sucrose (disaccharide), cellulose (polysaccharide) b. Lipids – fats, oils, waxes, phospholipids c. Proteins – enzymes, transport proteins, structural proteins 5 d. Nucleic Acids – DNA & RNA 16. Polymers are made up of monomers. What does this mean and give an example that illustrates this. Polymers are very large molecules made up of many smaller molecules (monomers) that are bonded together. Proteins are a polymer / macromolecule made up of many amino acids. Amino acids are the monomers / building blocks of a protein. 17. What do proteins do? In other words, why are they so important for living things? There a many types of proteins – they are the worker molecules of the cell. Types: enzymatic, structural, storage, defensive, transport, receptor, hormonal, and contractile/motor. 18. How are enzymes important in humans? Enzymes are biological catalysts, they speed up chemical reactions in our bodies. 19. What does it mean when we say that an enzyme is denatured? What can do this? When enzymes are denatured their shape changes. These changes often impact the active site (where the substrate binds) of the enzyme. This can prevent an enzyme from binding to the substrate which slows the chemical reaction. Heating, changing its pH, coming in contact with an alcohol can all potentially denature proteins. 20. Carbon is an element that is part of ___organic___________ compounds. 21. Why are carbon atoms so special when compared to other elements? In other words, what can carbon compounds do that most other atoms can’t? carbon atoms can form 4 covalent bonds, it can form very large / diverse molecules – long chains, rings, etc… 22. Describe the importance of lipids. Lipids serve very important roles in living things. They function in energy storage (fat), structure (phospholipids), protection (wax), and chemical messengers (steroids). 23. The more mitochondria that cells have will increase the amount of 6 _____ATP/energy_______________________ that the cells can create. 24. What happens when ATP becomes ADP? When the 3rd phosphate is removed from ATP energy is released. ATP → ADP + P + energy 25. The following question has three parts. Answer a and b to help you answer question c. a. Write the chemical equation for photosynthesis and label the reactants and products. 6CO2 + 6H2O → light(energy)+ chlorophyll → C6H12O6 + 6O2 Reactants Products b. Write the chemical equation for respiration and label the reactants and products. C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (ATP) Reactants Products c. Draw a diagram showing how cellular respiration and photosynthesis are related. Use the following terms: energy, light, carbon dioxide, oxygen, water, glucose Chemical energy = ATP 7 26. What is chlorophyll? Explain why it is an essential part of photosynthesis. Chlorophyll is the photosynthetic pigment of a plant found in the chloroplast. This pigment is essential for the conversion of solar energy (sun) into chemical energy (ATP) 27. 28. Define the following terms and classify them as either a lipid, protein, or carbohydrate. a. Amino Acid: building block of a protein; 20 different amino acids b. Fat: lipid responsible for stored energy c. Enzyme: protein that acts as a biological catalyst; speeds up chemical reactions in living things d. Sugar: carbohydrate responsible for quick energy Define macromolecules and list the four main macromolecules. Large molecules in living cells – “ giant molecules” also called polymers made up from many smaller molecules. Proteins, Carbohydrates, Lipids and Nucleic Acids 8 29. Use the chart below to answer the questions. The pH Scale for Common Substances a. The table above lists acids and bases. Where do the acids begin on the chart? Where do the bases begin on the chart? pH of 0 to 7 = acid; pH of 7 to 14 - base b. How do you determine which of the liquids above are the strongest base or acid? The lower the pH the more acidic the substance is – pH of 1 is much more acidic than pH of 7. The higher the pH the more basic the substance is – pH of 14 is much more basic than a pH of 7. 9 30. Describe the function of each of the cell structure listed below. a. Cell Membrane: regulate what enters and exits the cell b. Cell Wall: strong protective barrier outside of the cell membrane in plants, algae, and some bacteria c. Nucleus: contains the cell’s genetic material (DNA) and controls the cell’s activities; part of the endomembrane system d. Nuclear Envelope (Membrane): double membrane layer that surrounds the nucleus e. Nucleolus: small, dense region within most nuclei in which ribosome assembly begins f. Chromatin: genetic material of cell; DNA wrapped around histone proteins – loose and thread-like g. Mitochondria: releases energy from stored food; creates ATP; “powerhouse” of the cell h. Chloroplasts: site of photosynthesis; converts solar energy into chemical energy i. Ribosomes: site of protein synthesis; part of the endomembrane system if attached to the rough ER 10 j. Endoplasmic Reticulum (ER): involved in the manufacture and transport of proteins (rough ER w/ ribosomes) and lipids (smooth ER w/out ribosomes); smooth ER is also involved in the breakdown of toxins; part of the endomembrane system k. Golgi Body: packages and modifies substances for use within the cell and/or for export out of the cell; part of the endomembrane system l. Lysosomes: small vesicles (cell organelle) that contain digestive enzymes; produced by Golgi body; used to breakdown food and/or waste products m. Vacuoles: cell organelle that stores materials such as water, salts, proteins, and carbohydrates; plants have a large central vacuole that provide structural support n. Plastids: a double membrane bound organelle involved in the synthesis (production) and storage of food, and is commonly found within the cells of photosynthetic organisms, like plants o. Cytoskeleton: internal framework of a cell composed of protein filaments and microtubules in the cytoplasm and has a role in controlling cell shape, maintaining intracellular organization, and in cell movement. 11 31. Use the picture below to answer the following question. a. The figure above is a prokaryotic cell. What characteristics tell you that this is a prokaryotic cell and not a eukaryotic cell? Prokaryotic features: bacterial flagellum, capsule (outside of cell wall), DNA found in nucleoid region (not a nucleus), and no membrane bound organelles. 12