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BIOLOGY 101, EXAM 2
QUESTIONS WITH COMPLETE
AND ACCURATE ANSWERS.
Three cell parts found in all cells? -- Answer โโ DNA, plasma membrane, and cytoplasm or ribosomes What is the cell theory? -- Answer โโ The cell is the basic unit of life, all living things are made up of one or more cells, and all cells come from the reproduction of other cells Cells that do not have a nucleus are: -- Answer โโ prokaryotes DNA in bacterial/prokaryotic cells forms a: -- Answer โโ circle DNA in eukaryotic cells are: -- Answer โโ linear Why are cells small? -- Answer โโ Cells do not get very large because the surface area to volume ratio must be high to allow for the ready exchange of materials in and out of the cell What three cell parts are found ONLY in plant cells? -- Answer โโ cell wall, chloroplasts, and the large/central vacuole What is Endosymbiosis? -- Answer โโ The theory that some prokaryotic cells engulfed other prokaryotic cells thus forming membrane-bound structures (like mitochondria or chloroplasts) and ultimately giving rise to eukaryotic cells
What is the organelle site of the reaction called CELLULAR RESPIRATION in eukaryotic cells? -- Answer โโ Mitochondria What do you call the site of PROTEIN and LIPID SYNTHESIS in eukaryotic cells is an ENDOMEMBRANE SYSTEM? -- Answer โโ the Endoplasmic Reticulum What can you find in the nucleus? -- Answer โโ the nucleolus and DNA How can you distinguish between the ROUGH E.R. and the SMOOTH E.R.? -- Answer โโ the presence of RIBOSOMES in the rough E.R. What are the three structures that enable cells to move? -- Answer โโ cilia, flagella, and pseudopods What is found within the CHLOROPLASTS and is the site of PHOTOSYNTHESIS? -- Answer โโ thylakoids What are the folds within the MITOCHONDRIA called? -- Answer โโ cristae What are cytoplasmic bridges found between PLANT cells? (holes in the CELL WALL) -- Answer โโ plasmodesmata What are the cytoplasmic bridges found between ANIMAL cells? (openings in the CELL MEMBRANES) -- Answer โโ gap junctions Which organelle contains DIGESTIVE ENZYMES? -- Answer โโ the lysosome The lysosome is produced by the pinching off of portions of the membranes of the: -- Answer โโ Golgi bodies/apparatus What is the site of PROTEIN SYNTHESIS? -- Answer โโ Ribosomes What is the largest CYTOSKELETON component? -- Answer โโ the microtubules
What happens if a red blood cell is put in a Hypertonic solution? -- Answer โโ it will shrivel (plasmolysis) What happens if a plant cell is put in a Hypotonic solution? -- Answer โโ it will become rigid since the central vacuole creates TURGOR PRESSURE pushing against the cell wall which prevents wilting What are two examples of ENDOCYTOSIS? What do they do? What do they require? -- Answer โโ 1. Phagocytosis (which means "cell eating") takes in LARGE molecules or cells
- Pinocytosis (which means "cell drinking") takes in SMALL particles dissolved in fluid BOTH require ATP Glucose enters the cell through what process? Why? -- Answer โโ Glucose enters the cell through the process of FACILITATED diffusion since it uses carrier proteins and does not require energy input (passive transport) Carbon Dioxide (CO2) and Oxygen (O2) enters the cell through the phospholipid bilayer by what process? Why? -- Answer โโ They enter through the process of SIMPLE diffusion since they are non polar and do not require energy input (passive transport) How does water enter the cell, and by what process? -- Answer โโ Water enters the cell through PROTEINS in the membrane called AQUAPORINS by the process of OSMOSIS which does not require energy input (passive transport) What does ACTIVE transport require? -- Answer โโ ATP What is established by a positive charge on the outside of a nerve cell membrane? -- Answer โโ the sodium-potassium pump (Na-K) What are enzymes and what are their functions? -- Answer โโ Enzymes are CATALYSTS that speed up chemical reactions
If energy is stored in the product of a reaction, the chemical reaction is: -- Answer โโ Endergonic What does the SUBSTRATE bind to on an ENZYME? -- Answer โโ the active site Name 3 factors that affect the function of enzymes: -- Answer โโ 1. Temperature
- pH
- Salinity (also inhibitors) The enzyme shape changes very slightly once the enzyme and substrate bind together. What is this called? -- Answer โโ Induced fit What is the first law of thermodynamics? -- Answer โโ Energy is neither created nor destroyed, it just changes form What is the second law of thermodynamics? -- Answer โโ The disorder (entropy) of a system INCREASES with time. For living systems to MAINTAIN ORDERLINESS, they must Input energy from their environment What kind of energy does Sucrose have? And where is it stored? -- Answer โโ Sucrose has POTENTIAL energy, and this energy is stored in the CHEMICAL BONDS What is the cell's currency? (energy readily available to cells) -- Answer โโ ATP ATP is made by all cells by what process? -- Answer โโ Cellular respiration ATP supplies energy by giving up what? -- Answer โโ phosphate groups
Describe facilitated diffusion: -- Answer โโ Moves WITH the concentration gradient ([H] to [L]). No energy is required. Some structures involved are PROTEIN CARRIERS in the fatty acid bilayer. Some examples of the substances transported are GLUCOSE and AMINO ACIDS. Describe active transport: -- Answer โโ Moves AGAINST the concentration gradient ([L] to [H]). ATP is required. Some structures involved are the PROTEIN PUMP in the fatty acid bilayer. Some examples of the substances transported are the Sodium- Potassium (Na+ K+) pump and the Chlorine (Cl-) ion channel. Describe endocytosis: -- Answer โโ Moves AGAINST the concentration gradient ([L] to [H]). ATP is required. Some structures involved are PROTEINS and FATTY ACIDS (pseudopods for phagocytosis). Some examples of the substances transported are BACTERIA and LARGE MOLECULES like Insulin. Describe exocytosis: -- Answer โโ Moves AGAINST the concentration gradient ([L] to [H]). ATP is required. Some structures involved are PROTEINS and FATTY ACIDS. Some examples of the substances transported are LARGE MOLECULES like Insulin. Describe osmosis -- Answer โโ Moves WITH the concentration gradient ([H] to [L]). No energy is required. Some structures involved are AQUAPORINS between fatty acids. OCCURS IN WATER ONLY.
What is the first stage of cellular respiration? (the oxidation of glucose) -- Answer โโ glycolysis Where does glycolysis take place? -- Answer โโ the cytoplasm Glucose in glycolysis produces two 3-Carbon molecules called: -- Answer โโ pyruvates (pyruvic acid) Does glycolysis require oxygen? -- Answer โโ No In order for pyruvate to enter the mitochondria, what must be present? -- Answer โโ oxygen The second stage of cellular respiration is the oxidation of: -- Answer โโ pyruvates The oxidation of pyruvates results in the production of a 2-Carbon molecule called: -- Answer โโ acetyl Acetyl combines with: -- Answer โโ coenzyme A The third stage of cellular respiration is: -- Answer โโ the Kreb's cycle How many times does the Kreb's cycle turn to make one glucose? -- Answer โโ two times The fourth stage of cellular respiration is: -- Answer โโ the Electron Transport Chain (ETC) Where does the Electron Transport Chain take place? -- Answer โโ the cristae (of the mitochondria) What is established in the inter-membrane space while the electrons are passed down the Electron Transport Chain, which FUEL the pumping of ions across the membrane? -- Answer โโ The Proton (H+) Gradient
occurs in cytoplasm Photosynthesis formula: -- Answer โโ 12 Water (12(H2O) + 6 Carbon Dioxide (6(CO2) -to-> Glucose (C6H12O6) + 6 Oxygen (6(O2) + 6 Water (6(H2O) With light and chloroplasts Cellular respiration formula: -- Answer โโ Glucose (C6H12O6) + 6 Oxygen (6(O2) -to-> 36 ATP + 6 Water (6(H2O) + 6 Carbon Dioxide (6(CO2) With enzymes and mitochondria The energy found in glucose originates from what? -- Answer โโ the sun The organelle needed to produce glucose is ___? In what process? -- Answer โโ The chloroplasts produce glucose in the process of photosynthesis The organelle needed to break down glucose is ___? In what process? -- Answer โโ The mitochondria breaks down glucose in the process of cellular respiration Where can you find cellulose? -- Answer โโ the cell walls Cellulose is made up of: -- Answer โโ glucose molecules What is the name of organisms that do not obtain their energy from the sun but from GEOTHERMAL energy or from CHEMICALS? -- Answer โโ Chemotrophs Name the two raw materials needed for photosynthesis: -- Answer โโ Water (H2O) and Carbon Dioxide (CO2) The best color lights for plant growth are: -- Answer โโ red and blue
Carbon enters the ecosystem via the molecule called ___? During what process? -- Answer โโ Carbon Dioxide (CO2) during the process of photosynthesis The Light Dependent Reaction occurs in which organelle? -- Answer โโ The thylakoid membrane The Light Independent Reaction occurs in which organelle? -- Answer โโ The stroma (fluid) in the chloroplasts Describe the first stage of photosynthesis: -- Answer โโ It begins when an electron in the Chlorophyll A molecule is excited by a PHOTON of light in Photosystem II (p680). This results in the splitting of WATER and the release of OXYGEN through the STOMATES of the leaf. Describe how ATP is produced: -- Answer โโ In order for ATP to be produced, a PROTON GRADIENT must be established in the compartment of the mitochondria as electrons pass down the ELECTRON TRANSPORT CHAIN. The gradient provides the energy as the ions are pumped through the ATP SYNTHASE ENZYME for a phosphate to be added to ADP to become ATP. What can you find inside the THYLAKOID MEMBRANE that passes electrons from Photosystem II to Photosystem 1? -- Answer โโ Cytochrome proteins Describe the formation of NADPH: -- Answer โโ The electrons excited from the CHLOROPHYLL A (p700) in Photosystem I and the HYDROGEN pumped through the membrane are ultimately accepted by NADP+ to form NADPH What are the final products of the Light Dependent reaction? -- Answer โโ ATP and NADPH The Light Independent reaction uses ATP and NADPH to run the Calvin Cycle to produce what? -- Answer โโ 2 P Gal's or 1 Glucose
