Exam 2 Study Guide
Membranes
1. Define or describe the following terms: phospholipid bilayer, membrane protein, integral proteins, peripheral proteins, transmembrane, glycoproteins, glycolipids, passive transport, active transport, diffusion, equilibrium, osmosis, facilitated diffusion, lysis, cytolysis,
crenation, turgid, flaccid, plasmolysis, channel protein, carrier protein, ion channel, aquaporin, electrogenic pump, membrane potential, cotransport, exocytosis, endocytosis, phagocytosis, pinocytosis, and receptor-mediated endocytosis.
2. What are the functions of the cell membrane?
3. Describe the fluid mosaic model of cell membrane structure. What are the main components that make up cell membranes?
4. If given an image of the cell membrane, be able to label the different components. On which side of the cell membrane do you find carbohydrate chains? On which side of the cell membrane do you find peripheral proteins?
5. What affects the fluidity of the cell membrane?
6. What are the two types of transport proteins? How do they differ? Describe the different functions of membrane proteins.
7. What does selectively permeable mean? Which substances can easily move across the cell membrane? Which substances do not easily move across the cell membrane?
8. Do molecules stop moving during diffusion once equilibrium is reached?
9. Describe what happens to plant and animal cells in hypotonic, isotonic and hypertonic solutions. Where is the net flux of water in regards to the cell (i.e. into the cell, out of the cell)? What are the names of the states of plant and animal cells in each type of environment? What type of environment do plant cells prefer? What type of environment do animal cells prefer?
10. What are the main differences between passive and active transport? How are diffusion and facilitated diffusion different? What are some examples of facilitated diffusion?
11. Describe the steps that occur in the sodium-potassium pump. What do electrogenic pumps generate? Why are electrogenic pumps important?
12. What is cotransport?
13. Describe the 3 different kinds of endocytosis.
Match the appropriate term with its description.
A. Diffusion B. Active transport C. Osmosis
D. Phagocytosis E. Passive transport F. Facilitated diffusion
G. Pinocytosis H. Receptor-mediated endocytosis I. Exocytosis
_____ 1) Diffusion across a biological membrane.
_____ 2) Moves solutes against their concentration gradient.
_____ 3) Any spread of molecules from area of higher concentration to area of lower concentration.
_____ 4) Diffusion with the help of a transport protein.
_____ 5) Three types of endocytosis.
_____ 6) How cells bring liquid inside.
_____ 7) Diffusion of water across a semipermeable membrane from high to low concentration.
_____ 8) Carrier proteins need ATP to function.
_____ 9) Enables cell to bring inside large quantities of a specific kind of molecule.
_____ 10) How oxygen and carbon dioxide enter and leave cells.
_____ 11) Two types of passive transport.
_____ 12) How cells bring food inside.
_____ 13) Fusion of transport vesicle with membrane and dumping of contents outside of cell.
_____ 14) Helped by aquaporins.
Test your understanding of osmosis by predicting in each of the following cases whether water will enter cell (IN) or leave cell (OUT), or whether there will be no net movement of water (NONE). Assume that the cell membrane is permeable to water but not solutes.
_____ 1) Cell is exposed to hypertonic solution.
_____ 2) Cell is placed in salt solution whose concentration is greater than cell contents.
_____ 3) Due to disease, solute concentration of body fluid outside cell is less than solute
concentration of cells.
_____ 4) Cell is in isotonic solution.
_____ 5) A Paramecium (a single-celled creature) is placed in a drop of pure water for examination
under a microscope.
_____ 6) Solute concentration of cell is greater than solute concentration of surrounding fluid.
_____ 7) Cell is exposed to hypotonic solution.
_____ 8) Concentration of solutes inside cell is equal to concentration of solutes outside of cell.
_____ 9) Cytoplasm is more dilute than surrounding solution.
____ 10) Internal solute concentration of a cell is 45% while the concentration of solute outside of
cell is 75%.
_____ 11) Internal solute concentration of a cell is 80% while the concentration of solute outside
of cell is 20%.
Metabolism
1. Define or describe the following terms: metabolism, metabolic pathway, catabolic pathway, anabolic pathway, energy, kinetic energy, potential energy, chemical energy, thermal energy, heat, entropy, exergonic, endergonic, energy coupling, phosphorylation, enzyme, catalyst, activation energy, substrate, inhibitor, enzyme inhibition, competitive inhibition, noncompetitive inhibition, and feedback inhibition.
2. Explain the difference between the two different types of metabolic pathways.
3. What are some of the different forms of energy here on Earth?
4. Does energy flow or cycle on Earth?
5. What are the first and second laws of thermodynamics? What is meant by the term entropy?
6. Distinguish between exergonic and endergonic reactions.
7. Relate the change in Gibbs’ free energy to whether a chemical reaction is endergonic or exergonic. Understand the connection between the change in Gibbs’ free energy and whether a reaction will occur spontaneously or nonspontaneously.
8. How does energy coupling work?
9. Distinguish between ADP and ATP. How are they involved in energetic transformations? What three kinds of work occur in cells due to ATP breakdown?
10. How do enzymes work as catalysts in biological reactions? How do they affect the amount of activation energy needed to start reactions?
11. What does it mean when we say that enzymes are substrate specific?
12. Are enzymes consumed (or used up) during chemical reactions?
13. What are the two types of pathways that enzymes assist with?
14. Describe the induced fit model for how an enzyme interacts with its substrate.
15. How do temperature and pH affect enzyme activity? What does it mean when an enzyme becomes denatured?
16. What are coenzymes?
17. What is enzyme inhibition? Distinguish between competitive and noncompetitive inhibition. What is an allosteric site?
18. What are biochemical pathways? Describe what happens during feedback inhibition. Is feedback inhibition an example of competitive or noncompetitive inhibition?
Cellular Respiration and Fermentation
1. Define or describe the following terms:
Oxidation Reduction Electron transport chain
Chemiosmosis ATP synthase Substrate-level phosphorylation
NAD+/NADH FAD/FADH2 Coenzyme A
Citrate Oxidative phosphorylation
Fermentation Anaerobic respiration
2. Write out the summary chemical equation of aerobic respiration. What molecules are reduced and what molecules are oxidized?
3. What are the 4 phases of aerobic cellular respiration?
4. Draw and label a mitochondrion showing outer membrane, inner membrane, intermembrane space, cristae and matrix.
5. Describe what happens during glycolysis: where does glycolysis occur? what are the 2 phases that make-up glycolysis? what are the inputs? what are the outputs? how is ATP made?
6. Describe what happens during pyruvate oxidation: where does pyruvate oxidation occur? what are the inputs per glucose molecule? what are the outputs per glucose molecule? is ATP made?
7. Describe the Citric acid cycle: where does the Citric acid cycle occur? what are the inputs per glucose molecule? what are the outputs per glucose molecule? what happens to the carbons of glucose during the Citric acid cycle? how is ATP made?
8. Describe the electron transport chain and chemiosmosis: where do they occur? Explain what happens as electrons move down the electron transport chain. What is meant by the term chemiosmosis? What is the overall process by which ATP is made (hint: ETC + chemiosmosis equals what)? What is the total yield of ATP when one molecule of glucose is fully oxidized?
9. What are the possible pathways that can occur when oxygen is not available in the environment but cells still need to generate ATP? What are the 2 kinds of fermentation that can occur?
10. How does the energy yield of fermentation compare with that of aerobic cellular respiration?
11. Can fats and proteins be broken down during aerobic cellular respiration?
Photosynthesis
1. Define or describe the following terms:
Oxidation Reduction Electron transport chain
Chemiosmosis RuBP Rubisco Stomata
ATP synthase Photon Electromagnetic energy
Photosystem I Photosystem II Light-harvesting complexes
Primary electron acceptor Chlorophyll
Pigment molecules Reaction center NADP reductase
2. Write out the summary chemical equation for photosynthesis. What is reduced? oxidized?
3. Where does photosynthesis occur in the cell?
4. Where does the carbon dioxide and water used in photosynthesis come from?
5. Sketch and label a diagram of a chloroplast showing outer membrane, inner membrane, thylakoids, grana and stroma.
6. Distinguish between the light reactions and the Calvin cycle of photosynthesis.
7. Where in the chloroplast do the light reactions occur? Where in the chloroplast does the Calvin cycle occur?
8. What are the 2 products of the light reactions that are used in the Calvin cycle?
9. Describe what happens during the light reactions of photosynthesis by tracing the movement of electrons from water to NADPH.
10. Describe how ATP is made during the light reactions of photosynthesis.
11. Which colors of light are used during the photosynthetic process?
12. What compound in the Calvin cycle is regenerated each time the cycle is completed?
13. What is the key product of the Calvin cycle?
14. Summarize the Calvin cycle: what goes in, what comes out, what is consumed, what is regenerated?
15. How many turns of the Calvin cycle have to occur to make 1 molecule of G3P?
16. What happens to the G3P made within the chloroplast of a plant cell?
Label the diagram below summarizing the two important reactions of photosynthesis. Use the following terms to fill in the blanks.
Match the ingredients or products of photosynthesis with the appropriate phrases.
A. CO2 B. H2O C. C6H12O6 D. O2
E. ADP + P F. ATP G. NADP+ H. NADPH
I. Light
______ 1) Oxidized in the light reactions.
______ 2) Reduced in the Calvin cycle.
______ 3) Carries H and electrons from the light reactions to the Calvin cycle.
______ 4) Food produced by photosynthesis.
______ 5) Source of H and electrons that end up in glucose.
______ 6) Source of O atoms that end up in glucose.
______ 7) Where O atoms from water end up.
______ 8) Oxidized in the Calvin cycle.
______ 9) Reduced in the light reactions.
______ 10) Supplies energy to the Calvin cycle.
______ 11) Where C and O atoms in carbon dioxide end up.
______ 12) Recycled from the Calvin cycle to make ATP.
______ 13) Supplies energy to the light reactions.
______ 14) Gas produced by reactions in the thylakoids.
______ 15) Gas consumed by reactions in the stroma.
______ 16) Source of C for carbon fixation.
______ 17) Source of H for the Calvin cycle.
______ 18) Picks up energized electrons from reactions in thylakoids.
