Biology 101 - module 3 (A+ Graded 100% Verified)

Biology 101 - module 3 (A+ Graded 100% Verified) This is around the cell plasma membrane This is the "fence with gates" lipid bilayer with proteins Only certain substances can pass through the wall. What substances? Carbon dioxide, oxygen, and water What is diffusion? movement of molecules from high to low concentration areas Molecules are _______ly distributed throughout the medium evenly Molecules that CAN diffuse across the membrane O2, CO2, water and other small molecules Molecules that CANNOT diffuse across the membrane Glucose, ions, calcium and sodium Passive transport with the flow of protein gates, ferries Active transport against the flow of protein gates, requires energy Endocytosis portion of cell membrane engulfs particles Exocytosis portion of cell membrane releases particles Osmosis diffusion of water molecules High solute concentration INSIDE cell water moves IN (cell expands) High solute concentration OUTSIDE cell water moves OUT (cell shrinks) Same solute concentration on both sides no movement What sort of activities are cells involved in? making proteins building membranes taking in materials metabolism photosynthesis respiration chemical reactions Different forms of energy (4) mechanical chemical electrical heat 2 states of energy kinetic (motion) potential (stored) ______ can transform from one form to another energy Laws of thermodynamics 1. Energy is always lost during transformation 2. Systems naturally go from order to disorder _________ must maintain a high state of order which requires an input of energy living things small energy packets ATP in general, a chemical reaction involves reactants which interact to form _________________ new products (new molecules) energy releasing reactions exergonic (spontaneous, lower energy) energy requiring reactions endergonic (NOT spontaneous, higher energy) biological reactions coupling in some reactions, _____________ get transferred electrons excited electrons give off __________ with each transfer energy activation energy can be overcome by ______, __________, _______ heat, pressure and catalysts Role of an ________ is lowering activation energy enzyme enzymes used in metabolic pathways sequence of chemical reactions, each step helped by a unique enzyme photosynthesis plants capture sunlight energy, release oxygen respiration plants and animals break down carbohydrate producing energy and releasing carbon dioxide as a byproduct light-dependent reactions use sunlight to make ATPs and NADPHs light-independent reactions use ATPs and NADPHs to make glucose sun energy potential responses heat up glow excite electrons role of chlorophyll found in chloroplasts, reflects green chlorophyll forms the reaction center of a ________ photosystem Carbon dioxide can pass through the cell membrane. If carbon dioxide is in HIGH concentration INSIDE a cell, and LOW concentration outside, what will happen? carbon dioxide will move out of the cell by diffusion What can ONLY enter a cell by passive transport? sugars The movement of oxygen from the outside of a cell, where there is high concentration, to the inside, where it is low, is: diffusion Why does diffusion occur? the random motion of molecules What cannot diffuse through the plasma membrane but instead must go through the protein gates? glucose A bag containing a sugar solution is placed in a beaker of distilled water. The sugar cannot pass through the membrane of the bag but water can. What will happen? water will move into bag Random motion of molecules causes them to move from areas where they are in _________ concentration to areas where they are in ________ concentration. high; low A bag containing a sugar solution is placed in a beaker of distilled water. The sugar cannot pass through the membrane of the bag but water can. What will happen to the sugar concentration inside following osmosis? the sugar concentration will decrease A red blood cell is placed in a beaker of distilled water. What will happen to the red blood cell? It will expand as water moves in For a Paramecium in a pond its' problem is that because of osmosis it picks up the excess water For a Paramecium in a pond its' problem is that because of osmosis it picks up the excess water a plant cell that is well hydrated has high turgor pressure When materials move into cells through protein gates from high concentration to low concentration it is called. passive transport The type of molecule that ferries other molecules across the cell membrane proteins An amoeba picks up food particles from the environment by endocytosis The phagocytosis that white blood cells do is another name for endocytosis Gasoline represents what form of energy? chemical The energy in gasoline exists in what state? potential When the energy in gasoline is transformed in the internal combustion engine, what happens to most of it? it is lost as heat When the energy in gasoline is transformed in the internal combustion engine, what happens to most of it? it is lost as heat If 2 chemicals are placed together and a reaction occurs, we can say that the reaction was exergonic According to the collision theory of chemical reactions, the reason that adding heat to the reactants makes the reaction proceed is that it makes the molecules move faster and collide with more energy When a chemical reaction involves 2 simple molecules interacting to form a complex molecule, the reaction is endergonic Activation energy must be overcome in what types of reactions? both energy-requiring and energy-producing The breakdown of glucose into ATP is a _______________ reaction. energy-releasing In a coupling reaction... an energy-requiring reaction is coupled with an energy-releasing reaction In a biochemical pathway A -> B -> C -> D, feedback inhibition would involve the product D changing the enzyme that assists in converting A to B When excited electrons are passed from one molecule to another in an electron transport chain, each transition releases energy The main role of chlorophyll in photosynthesis is to capture energy from protons Electrons lost by chlorophyll during photosynthesis are regained when a water molecule is split Electrons excited by photons hitting a chlorophyll molecule are passed to electron transport chain The main purpose of the Calvin-Benson cycle is to build a carbohydrate molecule The enzyme that picks up carbon dioxide from the air is rubisco Why does photosynthesis slow down when plants close their stomata? Oxygen builds up in the leaves and blocks the enzyme used for picking up carbon dioxide. The oxygen released as a byproduct of photosynthesis comes from water Which kind of plant does the light-independent reactions of photosynthesis only at night? CAM plants Why can C4 plants photosynthesize when it is hot and dry but C3 plants cannot? C4 plants have an additional biochemical pathway that picks up carbon dioxide. The main product of respiration that is eliminated from the cell as waste is carbon dioxide The part of aerobic respiration that consists of breaking a carbohydrate in half is glycolysis Which part of aerobic respiration produces the most ATPs? Electron Transport Chain The majority of the carbon dioxide that is released by aerobic respiration comes from reactions in Krebs cycle Oxygen is used in the reactions in Electron Transport Chain The reactions that produce pyruvate are part of glycolysis When muscles produce lactic acid it is because of reactions in fermentation Slow-twitch muscle fibers are associated with many mitochondria Compare the energy content of ATP vs NADH. NADH has more Organisms that can only live without oxygen for very brief periods are called obligate aerobes The main purpose of the Calvin-Benson cycle is to build a carbohydrate molecule The enzyme that picks up carbon dioxide from the air is rubisco Why does photosynthesis slow down when plants close their stomata? The main purpose of the Calvin-Benson cycle is to build a carbohydrate molecule The enzyme that picks up carbon dioxide from the air is rubisco The main purpose of the Calvin-Benson cycle is to build a carbohydrate molecule the function of a catalyst is to lower activation energy When materials move into a cell through protein gates from low concentration to high concentration it is called active transport What can ONLY enter a cell by passive transport? sugars metabolic pathways sequence of chemical reactions, enzymes used in biological systems usually a protein molecule provides a place where reactants can meet and interact Endocytosis portion of cell membrane engulfs particles Exocytosis portion of cell membrane releases particles Osmosis diffusion of water molecules High solute concentration INSIDE cell water moves IN (cell expands)