Review sheet for Lecture test 2

Review for Lecture Test 2 

Chapter 4 Microbial Anatomy 

1. Know the general characteristics of a prokaryotic and a eukaryotic cell. 

1. Prokaryotic cells, like bacteria, lack a nucleus and membrane-bound organelles, while eukaryotic cells, like those in plants and animals, have a nucleus and other membrane-bound organelles 

2. Know the structural components of prokaryotic and eukaryotic cells. 

1. Prokaryotic cells, like bacteria, lack a nucleus and membrane-bound organelles, while eukaryotic cells, like those in plants and animals, have a nucleus and various organelles. 

3. Know the function and structure of organelles in eukaryotic cells. 

4. Know the characteristics of DNA in prokaryotic cells vs a eukaryotic cell.  Where is the DNA located? 

1. In prokaryotic cells, DNA is typically circular and located in the cytoplasm within a region called the nucleoid, while in eukaryotic cells, DNA is linear, organized into chromosomes, and housed within a membrane-bound nucleus 

5. Describe simple diffusion, facilitated diffusion, osmosis, active transport, and passive transport.  Know the differences between simple and facilitated diffusion. 

1. Passive Transport: 

1. Movement of molecules across a cell membrane without requiring the cell to expend energy (ATP). 

2. Active Transport: 

1. Movement of molecules across a cell membrane requiring the cell to expend energy (ATP), often against their concentration gradient (from low to high concentration). 

3. Simple Diffusion:  

1. Movement of small, non-polar molecules (like oxygen and carbon dioxide) directly across the cell membrane, following their concentration gradient (from high to low concentration).  

4. Facilitated Diffusion:  

1. Movement of larger or polar molecules across the cell membrane with the help of membrane proteins (channel or carrier proteins), still following the concentration gradient, but requiring assistance.  

5. Osmosis:  

1. The movement of water molecules across a semi-permeable membrane, from an area of high-water concentration to an area of low water concentration (or from low solute concentration to high solute concentration). 

6. Know the difference between a hypertonic, a hypotonic and an isotonic solution. 

1. a hypertonic solution has a higher solute concentration than a cell, causing water to leave the cell and shrink;  

2. a hypotonic solution has a lower solute concentration, causing water to enter the cell and swell;  

3. and an isotonic solution has the same solute concentration as the cell, resulting in no net water movement 

7. Know the difference between eukaryotic and most prokaryotic plasma membranes in terms of their cholesterol content. 

1. Eukaryotic plasma membranes contain significant amounts of cholesterol (or other sterols), while prokaryotic membranes typically lack cholesterol 

8. Know which microorganisms have cells walls and which don’t. Know whether or not protoplasts have a cell wall. 

1. Most bacteria, fungi, and plant cells possess cell walls, while animal cells and protozoans lack them, and protoplasts are cells without a cell wall 

9. Know the characteristics of endospores 

1. a thick, protective coat and dehydrated core containing DNA 

10. Know the similarities between mitochondria, chloroplasts and prokaryotic cells. 

1. their own circular DNA, 70S ribosomes, double membranes, and a history suggesting they evolved from endosymbiotic relationships. 

11. Know and recognize the size, shape and arrangement of bacterial cells. 

1. Size: 

1. Bacteria are generally small, ranging from approximately 0.2 to 5 micrometers (µm) in length. 

2. The smallest bacteria, like Mycoplasma, are about the size of the largest viruses. 

3. The longest bacterial rods can be as large as some yeasts and human red blood cells (7 µm) 

2. Shapes: 

1. Cocci: Spherical or oval shaped. 

2. Bacilli: Rod-shaped. 

3. Spirilla: Spiral or curved-shaped. 

4. Other shapes include vibrio (comma-shaped) and spirochetes (helical 

3. Cocci: 

1. Diplococci (pairs)  

2. Streptococci (chains)  

3. Staphylococci (clusters)  

4. Tetrads (groups of four)  

5. Sarcinae (cuboidal packets) 

4. Bacilli: 

1. Diplobacilli (pairs)  

2. Streptobacilli (chains)  

3. Palisades (arranged side-by-side like a fence)  

12. Know how antibiotics affect the cell wall of bacteria. 

1. Many antibiotics target bacterial cell walls, specifically the peptidoglycan layer, by interfering with its synthesis, leading to weakened or damaged cell walls and ultimately bacterial death. 

13. Is penicillin more or less effective against gram-negative bacteria than against gram-positive bacteria? Explain your answer. 

1. more effective 

14. Know how lysozymes affect bacterial cells.  What exactly do they do to bacterial cell walls? 

1. hydrolyzing the peptidoglycan layer, a crucial structural component, leading to cell lysis (bursting) and bacterial death. 

15. Describe the structure function of the glycocalyx in both prokaryotic and eukaryotic cells. 

1. protection, adhesion, and cell-cell communication 

16. Know the role of the capsules on bacterial cells. 

1. serve as a protective shield, aiding in adherence to surfaces, preventing phagocytosis, and protecting against desiccation and toxins, enhancing bacterial virulence 

17. Know the role of chromatophores in bacterial cells. 

1. facilitate photosynthesis by capturing light energy and converting it into chemical energy 

18. Know about the taxic movement of cells in response to attractants and repellants. 

1. Chemotaxis, the directed movement of cells in response to chemical stimuli, involves cells moving towards attractants (chemoattractant) and away from repellents (chemorepellents) 

19. Know the differences between fimbriae and pili. 

1. fimbriae are generally shorter, more numerous, and primarily involved in attachment, while pili can be longer, fewer in number, and involved in both attachment and DNA transfer 

20. Know what inclusions are and know function of the inclusions found on your lecture slides. 

1. non-membrane-bound, cytoplasmic structures that serve as storage for nutrients, pigments, or other cellular products, and are visible expressions of cell metabolism. 

Chapter 5 Microbial Metabolism 

1. Know the definition of metabolism, anabolism and catabolism. 

1. Metabolism encompasses all chemical processes in living organisms to maintain life 

2. anabolism is the building-up aspect (requiring energy)  

3. catabolism is the breaking-down aspect (releasing energy) 

2. What are metabolic pathways? 

1. series of interconnected chemical reactions that occur within cells to convert substrates (starting materials) into products 

3. How is ATP an intermediate between anabolism and catabolism? 

1. serving as the primary energy currency of the cell, capturing energy released during catabolism and then providing that energy to power the energy-requiring processes of anabolism 

4. Explain the collision theory 

1. for a chemical reaction to occur, reactant particles must collide with sufficient energy (activation energy) and the correct orientation 

5. What is the activation energy with regards to a chemical reaction? 

1. the minimum amount of energy required for reactants to overcome the energy barrier and transform into products 

6. What is the reaction rate as it relates to a chemical reaction? 

1. The speed at which a chemical reaction proceeds, measured as the change in concentration of reactants or products per unit time.   

7. What are catalysts? What are enzymes and how do they work? 

1. substances that speed up chemical reactions without being consumed, while enzymes are biological catalysts (usually proteins) that facilitate specific biochemical reactions by lowering the activation energy.   

8. Be able to identify the substrate and a product in a chemical reaction. 

1. the substrate is the molecule acted upon by an enzyme, while the product is the molecule(s) that result from the reaction.   

9. Know the properties of enzymes. 

1. highly specific, meaning they catalyze only certain reactions, and are efficient, requiring only small amounts to catalyze large quantities of substrate 

10. Know what an apoenzyme, a holoenzyme, a cofactor and a coenzyme is. 

1. An apoenzyme is the protein part of an enzyme that's inactive without a cofactor 

2. holoenzyme is the active enzyme complex formed   

3. apoenzyme binds to its cofactor 

11. What is the function of a coenzyme? 

1. assist enzymes in catalyzing biochemical reactions by binding to the enzyme's active site and facilitating the transfer of chemical groups, electrons, or hydrogen atoms 

12. What are the factors that influence enzyme activity?  Know the corresponding graphs that show the effect of these factors. 

1. temperature, pH, substrate and enzyme concentrations, and the presence of inhibitors 

13. Know how to identify if a compound is an enzyme or not (ase is found in the name of enzymes). 

1. many enzyme names end with the suffix "-ase," such as "lactase" or "lipase".   

14. What is the difference between a competitive and a non-competitive inhibitor? 

1. competitive inhibitors bind to the active site, competing with the substrate, while non-competitive inhibitors bind to an allosteric site, altering the enzyme's shape and preventing substrate binding 

15. Know the components of a redox (oxidation/reduction) reaction. 

1. the transfer of electrons between two species, one undergoing oxidation (loss of electrons) and the other undergoing reduction (gain of electrons).   

16. What is oxidation? 

1. the process or result of oxidizing or being oxidized. 

17. What is reduction? 

1. the act of making something, or of something becoming, smaller in size, amount, degree, importance, etc 

18. In a given redox reaction, know what compound is being reduced and what compound is being oxidized. 

1. the compound that loses electrons is oxidized, and the compound that gains electrons is reduced 

19. Know the three mechanisms by which ATP is generated. 

1. substrate-level phosphorylation, oxidative phosphorylation, and photophosphorylation 

20. Is ATP a long term or a short term storage molecule? 

1. short-term 

21. Know the products of glycolysis 

1. two molecules of pyruvate (or pyruvic acid), two molecules of ATP (net gain), and two molecules of NADH 

22. What happens during the preparatory and energy-conserving stages of glycolysis? 

1. the preparatory phase (first five steps) consumes energy (2 ATP) to convert glucose into two molecules of glyceraldehyde-3-phosphate (G3P) 

2. energy-conserving phase (last five steps) generates energy (4 ATP, 2 NADH) by oxidizing G3P into pyruvate.   

23. How many net molecules of ATP are produced in glycolysis? 

1. 2 ATP molecules per glucose molecule 

24. Know what happens in the intermediate step of respiration, before the Krebs cycle. 

1. converts pyruvate (a product of glycolysis) into acetyl-CoA, releasing carbon dioxide and generating NADH.   

25. Know the net products of the Krebs cycle. 

1. 3 NADH, 1 FADH2, 1 GTP (or ATP), and 2 CO2 

26. What are the three phases (stages) involved in the breakdown of carbohydrates? The greatest number of ATPs are produced in which phase? 

1.  glycolysis, the Krebs cycle (or citric acid cycle), and oxidative phosphorylation  

27. Know about the process of fermentation and how much energy is produced by this process. 

1. Fermentation is an anaerobic process where microorganisms, like bacteria and yeast, break down sugars (like glucose) in the absence of oxygen, producing energy in the form of ATP, but significantly less than aerobic respiration, yielding only 2 ATP molecules per glucose molecule 

28. Describe lactic acid and alcohol fermentation. 

1. Lactic acid fermentation converts pyruvate into lactic acid, while alcoholic fermentation converts pyruvate into ethanol and carbon dioxide, both processes occurring in the absence of oxygen 

29. During which phase of fermentation is ATP generated? 

1. glycolysis phase 

30. Describe how lipids and proteins undergo catabolism.  Where are fatty acids oxidized? 

1. in the mitochondria through a process called beta-oxidation.   

31. What is photosynthesis? 

1. the process by which plants, algae, and some bacteria convert light energy, typically from sunlight, into chemical energy (sugars) using carbon dioxide and water, releasing oxygen as a byproduct 

32. Compare and contrast the light-dependent and light-independent reactions of photosynthesis. 

1. light-dependent reactions, which convert light energy into chemical energy (ATP and NADPH), and light-independent reactions (Calvin cycle), which use this chemical energy to convert carbon dioxide into glucose 

33. Know what goes on during photophosphorylation.  Compare and contrast cyclic and non-cyclic photophosphorylation. 

1. the main difference being the involvement of photosystems and the products forme 

34. Compare and contrast oxidative phosphorylation and photophosphorylation. 

1. oxidative phosphorylation uses energy from the electron transport chain in mitochondria, while photophosphorylation uses light energy in chloroplasts.   

35. What is the difference between oxygenic photosynthesis and anoxygenic photosynthesis? 

1. oxygenic photosynthesis uses water as an electron donor and produces oxygen, while anoxygenic photosynthesis uses other molecules (like hydrogen sulfide) and does not produce oxygen.   

36. What are the products of the light dependent reaction? 

1. ATP, NADPH, and oxygen (O2) 

37. What is the product of the light independent reaction? 

1. glyceraldehyde-3-phosphate (G3P) 

38. Know the nutritional classification of organisms. 

1. autotrophs (making their own food) or heterotrophs (obtaining food from other sources) 

39. What are phototrophs, chemotrophs, autotrophs and heterotrophs? 

1. Phototrophs: Organisms that use light as their primary energy source, like plants during photosynthesis. 

2. Chemotrophs: Organisms that obtain energy through the oxidation of chemical compounds, either organic or inorganic. 

3. Autotrophs: Organisms that synthesize their own food from inorganic sources, like carbon dioxide, using energy from light (photoautotrophs) or chemical reactions (chemoautotrophs). 

4. Heterotrophs: Organisms that cannot synthesize their own food and must obtain organic molecules from other organisms or organic sources 

40. Know about the microbial diversity of organisms as it relates to their use of energy. 

1. Microbial diversity is crucial for energy cycling and ecosystem function, with microbes utilizing various energy sources like sunlight, organic compounds, and even inorganic minerals, showcasing a wide range of metabolic pathways 

41. What are photoautotrophs, photoheterotrophs, chemoautotrophs and chemoheterotrophs. Which of the four use glucose for carbon and energy? 

1. Photoautotrophs: These organisms use light energy to synthesize organic compounds from carbon dioxide. Examples include plants and cyanobacteria.  

2. Photoheterotrophs: These organisms use light as their energy source but obtain carbon from organic compounds, not carbon dioxide.  

3. Chemoautotrophs: These organisms obtain energy from chemical reactions involving inorganic compounds like hydrogen sulfide or methane and use carbon dioxide as their carbon source.  

4. Chemoheterotrophs: These organisms obtain both energy and carbon from preformed organic compounds like glucose. 

5.  Chemoheterotrophs are organisms that use glucose for both carbon and energy 

42. Are Cyanobacteria photoautotrophs, photoheterotrophs, chemoautotrophs or chemoheterotrophs? 

1. Cyanobacteria are photoautotrophs 

43. Which of the following nutritional group (microbial diversity groupings above) of organisms contain the most pathogens? 

1. chemoheterotrophs 

44. In green and purple bacteria, electrons to reduce CO₂ can come from? 

1. CO2 

45. Is ATP used for long term or short term storage of energy? 

1. Short-term

47. What are amphibolic pathways?  Describe their properties. 

1. metabolic pathways that function in both catabolic (breaking down molecules) and anabolic (building up molecules) processes, serving as a central hub for energy production and biosynthesis.