Biology Exam 1 - Study Questions PDF

1. Water molecules form which type of bond with other water molecules? Hydrogen bonds 2. What are the properties of water that make it important for life? Cohesion and adhesion, Large heat capacity, Lower density as a solid, Good solvent. Metabolism 3. What is the most abundant molecule in...

1. Water molecules form which type of bond with other water molecules? Hydrogen bonds 2. What are the properties of water that make it important for life? Cohesion and adhesion, Large heat capacity, Lower density as a solid, Good solvent. Metabolism 3. What is the most abundant molecule in the cell? Water 4. What are the primary elements that make up all living organisms? C, H, O, N, P, S 5. What are the biologically important as ions? Fe2+, Fe3+, Mg2+, Ca2+, K+, Na+, Cl-, Mg2+,, K+ 6. What elements make up the basic structure of carbohydrates? Carbohydrates are composed of carbon (C), hydrogen (H), and oxygen (O). 7. What are some monomers and polymers of carbohydrates? Monomers: Simple sugars like glucose. Polymers: Polysaccharides such as starch, glycogen, and cellulose 8. What are the functions of carbohydrates? Carbohydrates primarily serve as a fuel source for cellular processes and play a role in cell recognition and structural functions in plants and invertebrates 9. In what form do plants and animals store energy, short term? Plants store energy short-term as starch. Animals store it short-term as glycogen 10. Why can certain organisms not digest certain polymers of carbohydrates? Certain organisms cannot digest some carbohydrate polymers, like cellulose, because they lack the enzyme to break the β-glycosidic linkages. 11. What feature is common to ALL lipids? All lipids are hydrophobic (non-soluble in water) 12. What are the different types of lipids? Fats, sterols, and phospholipids 13. What are the functions of the various types of lipids? Fats: Long-term energy storage and insulation Sterols: Regulation (e.g., steroid hormones) and maintaining cell membrane fluidity Phospholipids: Form biological membranes 14. What is the difference between saturated and unsaturated fatty acids? Saturated fats have no double bonds in the fatty acid chains, making them solid at room temperature. Unsaturated fats have one or more double bonds, which create kinks and make them liquid at room temperature. 15. In what form do plants and animals store energy, long term? Plants store long-term energy as starch and oils Animals store it as fats 16. What are the monnomers and polymers of proteins? Monomers: Amino acids. Polymers: Polypeptides or proteins. 17. Why are some amino acids consider essential amino acids? Some amino acids are essential because the body cannot synthesize them; they must be obtained through diet. 18. What are complete proteins? Complete proteins contain all essential amino acids in the right proportions. 19. What are the various function of proteins? Proteins serve structural, protective, regulatory, contractile, transport, and catalytic functions in cells. 20. What are the different parts of an amino acid? Each amino acid has an amino group, carboxyl group, hydrogen atom, and a unique side chain (R group). 21. That parts of an amino acid influence the structure and functiono of a protein? The R group (side chain) determines an amino acid’s properties and influences protein folding and function. 22. What things can affect the structure of a protein? Environmental factors like pH and temperature can affect protein structure. 23. What does it mean to denature a protein? Denaturation is the loss of a protein’s structure and function, typically caused by extreme pH or high temperatures. 24. Why are most proteins denatured by extreme pH and high temperatures. 25. What are enzyme? Enzymes are proteins that act as biological catalysts, speeding up chemical reactions by lowering activation energy. 26. What how do enzymes function? Enzymes function by binding substrates at their active site and converting them into products, without being consumed in the reaction. 27. What type of macromolecule combines with proteins for form glycoproteins on the cell membrane? Carbohydrates 28. What type of macromolecules primary functionis to store information and transfer? Nucleic acids (DNA and RNA) 29. What are the monomers and polymers of nucleic acids? Monomers: Nucleotides. Polymers: DNA and RNA. 30. What nucleotides are found in DNA? Adenine (A), thymine (T), cytosine (C), and guanine (G). 31. What nucleotides are found in RNA? Adenine (A), uracil (U), cytosine (C), and guanine (G) 32. What is complamentary base pairings in DNA and between DNA and RNA? In DNA, A pairs with T, and C pairs with G. In RNA, A pairs with U, and C pairs with G. 33. RNA plays an improtant role in what process? Protein synthesis, including transcription and translation​ 34. What is the cell theory? Cell theory states that (1) all living organisms are composed of one or more cells, (2) the cell is the most basic unit of life, and (3) all cells arise from pre-existing cells​ 35. Why is it not accurate to say that Matthias Schleiden and Theodor Schwann developed the cell theory? While Schleiden and Schwann contributed significantly to cell theory by establishing that all organisms are made of cells, they did not fully develop the theory. Rudolf Virchow later added that cells come from pre-existing cells, a critical aspect of the theory 36. What is the difference between prokaryotic and eukaryotic cells? Prokaryotic cells lack membrane-bound organelles and a nucleus, while eukaryotic cells have complex, compartmentalized structures, including a nucleus 37. What groups make up prokaryotes? Prokaryotes include Bacteria and Archaea​ 38. What property of phospholipids cause them to form a phospholipid bilayer of the cell membrane? Phospholipids are amphipathic, meaning they have hydrophobic (water-repelling) tails and hydrophilic (water-attracting) heads. This property causes them to arrange themselves in a bilayer in cell membranes​ 39. What is the fluid mosaic model of the cell membranes and what keeps the phospholipids from falling apart? This model describes the cell membrane as a flexible layer of phospholipids with embedded proteins, cholesterol, and carbohydrates. Hydrophobic interactions between phospholipid tails help maintain the bilayer's integrity 40. Related to their amino acid primary structure, what holds some proteins in cell membranes? Hydrophobic regions in proteins help anchor them within the membrane by interacting with the hydrophobic interior of the phospholipid bilayer​ 41. What are the functions of the cell membrane? regulates the entry and exit of substances, provides structural support, enables cell communication, and participates in cell identification​ 42. What structure is the outermost feature on the surface of a plant cell? Cell Wall 43. What types of organelles are theorized to have originated from independently living prokaryotes? Mitochondria and chloroplasts 44. What are the three lines of evidence that support the endosymbiotic theory of organelles? Double membranes in mitochondria and chloroplasts. Presence of circular DNA in these organelles, similar to bacterial DNA. Ribosomes within mitochondria and chloroplasts resemble bacterial ribosomes 45. Which organelle's primary function is the storage and organization of information? Nucleus 46. What organells are surrounded by a double membrane? The nucleus, mitochondria, and chloroplasts 47. The cytoskeleton is composed of what macromolecules? Protein fibers, including microtubules, intermediate filaments, and microfilaments 48. What is the function of the cytoskeleton? Provides structural support, enables cell shape maintenance, and facilitates the movement of organelles and molecules within the cell​ 49. In what type of organisms are mitochondria found? Mitochondria are found in eukaryotic cells, including animals, plants, and fungi 50. Which organelles contains hydrolytic enzymes associated with the digestion of macromolecules? Lysosomes 51. Which of the following organelles is responsible for degrading waste within the cell? Lysosomes 52. In what organelle would you find most of the chromatin in the cell? Nucleus 53. Where are cell membrane components synthesized? The endoplasmic reticulum, primarily the rough ER for proteins and smooth ER for lipids 54. What organelles are part of the endomembrane system? The nuclear envelope, endoplasmic reticulum (ER), Golgi apparatus, lysosomes, and vesicles 55. Structurally, what makes the endomembrane system possible? The endomembrane system is composed of interconnected membrane structures within the cell​ 56. What is the function of the endomembrane system? It processes, modifies, packages, and transports biomolecules within the cell​ 57. In which organelle are lipids synthesized and modified within the eukaryotic cell? The smooth endoplasmic reticulum​ 58. In structure and function, what is the difference between the rough endoplasmic reticulum and the smooth endoplasmic reticulum? The rough ER has ribosomes on its surface for protein synthesis, while the smooth ER lacks ribosomes and is involved in lipid synthesis and detoxification 59. Where does protein synthesis occur in the cell? Occurs on ribosomes, which can be free-floating in the cytoplasm or attached to the rough ER​ 60. What is the function of the Golgi Apparatus? Modifies, sorts, and packages proteins and lipids for transport within or outside the cell​ 61. What are the channels called that run through the cell wall between plant cells that allow intercellular communication? Plasmodesmata 62. What is the function of the mitochondria? Produce ATP, the cell’s primary energy currency, through cellular respiration​ 63. In what types of orgsanisms would you find mitochondria? All eukaryotic organisms, including animals, plants, fungi, and protists​ 64. What cellular structures would you find in plant cells, but not animal cells? Plant cells have a cell wall, chloroplasts, and a large central vacuole, which are not present in animal cells 65. What is the function of chloroplasts? Carry out photosynthesis 66. In what organisms would you find chloroplasts? Plants 67. What are the functions of the large central vacuole in plants? Stores water, maintains cell pressure, stores nutrients and waste, and enables rapid cell growth using mostly water​ 68. What is the difference between vacuoles in plants and animals? Plant cells usually own large central vacuole, whereas animal cells have smaller, more numerous vacuoles primarily for storage 69. What does the net movement of molecules from an area of high concentration to an area of low concentration? Diffusion 70. What is the difference between a solute and a solvent? A solute is the substance dissolved in a solution, while the solvent is the substance in which the solute dissolves​ 71. What do we call the movement of water across a selectively (or semipermeable) membrane? Osmosis 72. What is the difference between a hypotonic, hypertonic and isotonic solution? Hypotonic: Lower solute concentration outside the cell, causing water to move into the cell. Hypertonic: Higher solute concentration outside the cell, causing water to move out. Isotonic: Equal solute concentration inside and outside, with no net water movement 73. What is the difference between active and passive transport? Active transport requires energy to move substances against their concentration gradient, while passive transport does not require energy and moves substances down their gradient​ 74. Osmosis and diffusion are examples of what type of transport? Passive transport​ 75. In which direction would water move in a cell placed in an isotonice, hypotonic and hypertonic solution? Isotonic: Water moves equally in and out of the cell. Hypotonic: Water enters the cell, potentially causing it to swell. Hypertonic: Water leaves the cell, causing it to shrink​ 76. Where does the energy for almost all life on earth originate? The sun 77. What is energy?  The ability to do work, such as moving matter against an opposing force. It includes kinetic energy (motion) and potential energy (stored energy)​ 78. What are the first and second law of thermodynamics and how do they relate to live on Earth? First Law: Energy cannot be created or destroyed, only transformed. This means all energy on Earth is transferred, such as sunlight converted into chemical energy by plants. Second Law: Energy transformations increase entropy (disorder), with some energy lost as heat. This limits energy efficiency in biological processes 79. What is the difference between potential and kinetic energy? Potential energy is stored energy due to an object's position, while kinetic energy is the energy of motion 80. Structually, how are mitochondria and chlorplast similar? Both have a double membrane and their own circular DNA 81. What are the two general forms of energy in used in cellular respiration and photosyntesis? chemical energy (stored in molecules) and light energy (in photosynthesis)​ 82. Structurally, what part of ATP provides it with so much metabolic energy? The high-energy phosphate bonds 83. What required for a plant to carry out photosynthesis? Light energy, carbon dioxide (CO₂), and water (H₂O) 84. While not directly involved in photosynthesis, why are chlorophyll b and the carotenoids so important? These accessory pigments absorb light wavelengths that chlorophyll a does not, broadening the range of light that can drive photosynthesis 85. Which color of light would be LEAST effective in powering photosynthesis? Green light is least effective since chlorophyll reflects it rather than absorbing it​ 86. Photosynthetically speaking, are pigment molecules? Pigment molecules, like chlorophyll, absorb light energy and are essential for capturing solar energy in photosynthesis 87. How does the color we see relate to the absorbance or reflectance of light? The color we see is the wavelength of light reflected by an object, while other wavelengths are absorbed​ 88. What is the overall process of photosynthesis? Photosynthesis converts light energy, water, and CO₂ into glucose and oxygen (O₂)​ 89. What are the products of the light dependent reactions of photosynthesis? ATP, NADPH, and O₂ 90. When light excites an electron, what are the two potential fates? Excited electrons can (1) return to their ground state, releasing energy as light or (2) be transferred to an electron acceptor​ 91. The atoms of oxygen gas produced during photosynthesis originates from what molecule? The splitting of water molecules​ 92. When light splits water molecules, what are the resulting products of the splitting of water in photosynthesis? Splitting water releases O₂, electrons, and protons (H⁺ ions)​ 93. What products of the light dependent reaction of photosynthesis are used in the Calvin cycle? ATP and NADPH 94. What happens in the Fixation step of the Calvin Cycle (light independent reactions)? CO₂ is attached to a 5-carbon molecule, forming an unstable 6-carbon compound that splits into two 3-carbon molecules​ 95. What happens in the Sugar formation (Reduction) step of the Calvin Cycle (light independent reactions)? Energy from ATP and NADPH reduces the 3-carbon molecules, which are then used to produce glucose​ 96. What happens in the Regeneration step of the Calvin Cycle (light independent reactions)? Five 3-carbon molecules are rearranged to regenerate the 5-carbon molecule that accepts CO₂, allowing the cycle to continue​ 97. What are the products of the Calvin Cylce that are used during the light reaction of photosynthesis? Sugars 98. What is the overall process of respiration? Converts glucose and O₂ into ATP, CO₂, and H₂O 99. In what organisms does glycolysis occur? All organisms 100. Where does glycolysis occur? Cytoplasm 101. In which steps of cellular respiration is CO2 lost? During the conversion of pyruvate to acetyl-CoA and in the Krebs Cycle​ 102. What is pyruvate converted to before it is transported into the mitochondria for use in the Kreb cycle? Acetyl-CoA 103. What are some high energy electron carriers? NADH and FADH₂ 104. Why are the high energy electron carriers from glycolysis and the Kreb cycle important? Transfer high-energy electrons to the electron transport chain, driving ATP production​ 105. What is the final electron acceptor in the Electron Transport Chain of Cellular Respiration? Oxygen (O₂) 106. In what step of respiration is most of the energy produced? The electron transport chain produces the most ATP during cellular respiration​ 107. What is a chemiosmotic gradient? This gradient is a difference in proton (H⁺) concentration across a membrane, used to generate ATP​ 108. Directly where does the energy come from that generates the chemiosmotic gradients in chloroplast and mitochondria? Comes from high-energy electrons moving through the electron transport chain in mitochondria and chloroplasts 109. What do the chemiosmotic gradients in chloroplast and mitochondria generate?\ ATP 110. Why is it necessary to convert energy from sugars, a chemical potential energy, into energy in ATP, another type of chemical potential energy? ATP provides a more accessible form of energy than sugars for cellular reactions, allowing cells to efficiently manage energy needs​