Medical Biology 2 Alklausen like
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Questions and Answers

What is the primary role of NADH in cellular respiration?

  • Directly synthesizing ATP
  • Storing genetic information
  • Transporting electrons in the electron transport chain (correct)
  • Providing structure to the cell membrane
  • Acting as an enzyme in glycolysis

    • Which molecule is a common energy currency in the cell?

  • Amino acid
  • Glycerol
  • Glucose
  • Fatty acid
  • ATP (Adenosine triphosphate) (correct)

    • During photosynthesis, the oxygen released comes from:

  • NADPH
  • Carbon dioxide
  • ATP
  • Water (correct)
  • Glucose

    • In the absence of oxygen, some cells can obtain energy by:

    <p>Glycolysis followed by fermentation</p> Signup and view all the answers

    What is the primary function of cholesterol in the cell membrane?

    <p>To transport molecules across the membrane</p> Signup and view all the answers

    Which type of molecule typically acts as a cell-surface marker?

    <p>Nucleic acids</p> Signup and view all the answers

    How do channel proteins in the plasma membrane function?

    <p>They provide structural support to the membrane</p> Signup and view all the answers

    In facilitated diffusion, molecules move:

    <p>Against the concentration gradient</p> Signup and view all the answers

    What is the primary function of ATP in cellular processes?

    <p>To provide energy for cellular activities</p> Signup and view all the answers

    What is the relationship between an enzyme and its substrate?

    <p>The substrate binds to the enzyme's active site</p> Signup and view all the answers

    Which statement accurately describes the second law of thermodynamics?

    <p>In every energy transfer, some energy becomes unavailable to do work</p> Signup and view all the answers

    Catabolism and anabolism are:

    <p>Respectively, energy-releasing and energy-consuming processes</p> Signup and view all the answers

    What is the role of an enzyme's active site?

    <p>To bind the substrate and lower the activation energy</p> Signup and view all the answers

    An exergonic reaction is one that:

    <p>Releases energy</p> Signup and view all the answers

    The ultimate source of energy for most life on Earth is:

    <p>The sun</p> Signup and view all the answers

    What is a cofactor?

    <p>A non-protein chemical compound that assists enzyme function</p> Signup and view all the answers

    Activation energy is:

    <p>The energy required to start a reaction</p> Signup and view all the answers

    What is the primary purpose of the light reactions in photosynthesis?

    <p>To generate ATP and NADPH</p> Signup and view all the answers

    In the context of metabolism, anabolic pathways:

    <p>Involve the synthesis of complex molecules</p> Signup and view all the answers

    Which term describes the sum of all chemical reactions within a living organism?

    <p>Metabolism</p> Signup and view all the answers

    What is the primary role of transport proteins in the plasma membrane?

    <p>To facilitate the movement of molecules across the membrane</p> Signup and view all the answers

    Which term describes the movement of a solute from an area of high concentration to an area of low concentration?

    <p>Simple diffusion</p> Signup and view all the answers

    The fluidity of the plasma membrane is affected by:

    <p>The types of phospholipids and presence of cholesterol</p> Signup and view all the answers

    What is the function of receptor proteins in the plasma membrane?

    <p>To bind to specific molecules outside the cell and transmit signals inside the cell</p> Signup and view all the answers

    Which molecules are typically unable to pass through the plasma membrane without assistance?

    <p>Large, polar molecules and ions</p> Signup and view all the answers

    In the sodium-potassium pump, what is the ratio of sodium to potassium ions transported?

    <p>3 Na+ out, 2 K+ in</p> Signup and view all the answers

    Gap junctions in animal cells are similar to what structures in plant cells?

    <p>Plasmodesmata</p> Signup and view all the answers

    Which process is used by cells to secrete large molecules, such as proteins?

    <p>Exocytosis</p> Signup and view all the answers

    What is the primary function of the electron transport chain in chloroplasts?

    <p>Producing ATP</p> Signup and view all the answers

    What is the primary function of the plasma membrane in cells?

    <p>Regulation of the passage of substances into and out of the cell</p> Signup and view all the answers

    Which model describes the structure of the plasma membrane?

    <p>Fluid mosaic model</p> Signup and view all the answers

    Which molecule is a major component of cell membranes and forms a bilayer?

    <p>Phospholipids</p> Signup and view all the answers

    Integral membrane proteins are characterized by:

    <p>Spanning the entire membrane</p> Signup and view all the answers

    What is the main role of membrane proteins?

    <p>Transport of molecules and cell signaling</p> Signup and view all the answers

    Which type of membrane protein spans the entire lipid bilayer?

    <p>Integral proteins</p> Signup and view all the answers

    Which process describes the movement of water across a semipermeable membrane?

    <p>Osmosis</p> Signup and view all the answers

    In facilitated diffusion, transport across the membrane is assisted by:

    <p>Carrier proteins or channels</p> Signup and view all the answers

    Which type of transport requires energy to move substances against their concentration gradient?

    <p>Active transport</p> Signup and view all the answers

    What is the role of cholesterol in the plasma membrane?

    <p>It maintains membrane fluidity</p> Signup and view all the answers

    Cell surface receptors are primarily involved in:

    <p>Cell-to-cell communication</p> Signup and view all the answers

    What does anabolism refer to?

    <p>The consumption of energy to build complex molecules</p> Signup and view all the answers

    Which molecule serves as a primary electron donor in photosynthesis?

    <p>Water</p> Signup and view all the answers

    What is the significance of enzyme catalysts in biological systems?

    <p>They decrease the activation energy of reactions</p> Signup and view all the answers

    What do catabolic pathways do?

    <p>Typically consume energy</p> Signup and view all the answers

    What is the energy released by the hydrolysis of ATP used for?

    <p>Catalyzing biochemical reactions</p> Signup and view all the answers

    In cellular respiration, what is the final electron acceptor in the electron transport chain?

    <p>Oxygen</p> Signup and view all the answers

    Which process is not part of aerobic respiration?

    <p>Lactic acid fermentation</p> Signup and view all the answers

    What role do vitamins play in the cell?

    <p>Coenzymes or precursors for coenzymes</p> Signup and view all the answers

    What enzyme is responsible for carbon fixation in the Calvin cycle?

    <p>Rubisco (Ribulose-1,5-bisphosphate carboxylase/oxygenase)</p> Signup and view all the answers

    What is the principle known as where energy cannot be created or destroyed, but can only be transformed from one form to another?

    <p>The first law of thermodynamics</p> Signup and view all the answers

    In photosynthesis, light energy is converted into what type of energy?

    <p>Chemical energy</p> Signup and view all the answers

    What is the primary function of the electron transport chain in mitochondria?

    <p>Producing ATP</p> Signup and view all the answers

    What does the term 'selective permeability' of a membrane refer to?

    <p>Allowing only certain substances to pass through</p> Signup and view all the answers

    Which process can move substances from a lower to a higher concentration across the plasma membrane?

    <p>Active transport</p> Signup and view all the answers

    What is the main function of the carbohydrates attached to the external surface of the plasma membrane?

    <p>Mediating cell-cell interactions</p> Signup and view all the answers

    The sodium-potassium pump is an example of:

    <p>An active transporter</p> Signup and view all the answers

    What is the role of membrane receptors in signal transduction?

    <p>To receive and transmit signals to the cell's interior</p> Signup and view all the answers

    Desmosomes are cell structures that are particularly important for:

    <p>Providing mechanical strength to tissues</p> Signup and view all the answers

    What is the primary function of protein channels within the cell membrane?

    <p>To facilitate the movement of molecules across the membrane</p> Signup and view all the answers

    What are glycolipids and glycoproteins primarily involved in?

    <p>Cell-cell recognition</p> Signup and view all the answers

    Lipid rafts in the plasma membrane are:

    <p>Areas rich in specific types of lipids and proteins</p> Signup and view all the answers

    What is the primary function of receptors in the plasma membrane?

    <p>Transmitting signals from outside to inside the cell</p> Signup and view all the answers

    What term describes the movement of a substance from a lower concentration to a higher concentration with the use of energy?

    <p>Active transport</p> Signup and view all the answers

    What is the role of integral membrane proteins?

    <p>Facilitating the movement of molecules across the membrane</p> Signup and view all the answers

    During photosynthesis, the oxygen released comes from:

    <p>Water</p> Signup and view all the answers

    Which compound is not involved in the Calvin cycle?

    <p>Glucose-6-phosphate</p> Signup and view all the answers

    The process of oxidative phosphorylation is associated with:

    <p>The synthesis of ATP using energy from redox reactions</p> Signup and view all the answers

    Where does aerobic respiration take place in eukaryotic cells?

    <p>Mitochondria</p> Signup and view all the answers

    Which type of molecule is typically involved in the synthesis of new lipids?

    <p>Phospholipids</p> Signup and view all the answers

    What is the main function of channel proteins in the plasma membrane?

    <p>Facilitate the passive movement of substances</p> Signup and view all the answers

    In facilitated diffusion, how do molecules move across the membrane?

    <p>From an area of higher concentration to an area of lower concentration</p> Signup and view all the answers

    What primarily affects the fluidity of a cell membrane?

    <p>The types of phospholipids and the presence of cholesterol</p> Signup and view all the answers

    What is the main function of glycolipids in the cell membrane?

    <p>Cell signaling and recognition</p> Signup and view all the answers

    What is the primary role of glycolipids in the cell membrane?

    <p>Signal transduction</p> Signup and view all the answers

    Which process involves the engulfing of liquid into the cell through membrane invagination?

    <p>Pinocytosis</p> Signup and view all the answers

    What is the significance of the plasma membrane's fluid nature?

    <p>It allows for the movement of lipids and proteins within the membrane</p> Signup and view all the answers

    In receptor-mediated endocytosis, the molecule that the receptor binds to is known as:

    <p>Ligand</p> Signup and view all the answers

    The concentration gradient of a substance across a membrane represents:

    <p>Potential energy</p> Signup and view all the answers

    What role does cholesterol play in the plasma membrane at low temperatures?

    <p>Enhances fluidity</p> Signup and view all the answers

    Which characteristic of the plasma membrane allows for the selective entry and exit of substances?

    <p>Permeability</p> Signup and view all the answers

    What is the function of receptor proteins in the plasma membrane?

    <p>To bind to specific molecules outside the cell and transmit signals inside the cell</p> Signup and view all the answers

    What is the role of transport proteins in the plasma membrane?

    <p>To facilitate the movement of molecules across the membrane</p> Signup and view all the answers

    Which molecules are typically unable to pass through the plasma membrane without assistance?

    <p>Large, polar molecules and ions</p> Signup and view all the answers

    Ion channels in the plasma membrane:

    <p>Facilitate the diffusion of ions across the membrane</p> Signup and view all the answers

    What is the ratio of sodium to potassium ions transported in the sodium-potassium pump?

    <p>3 Na+ out, 2 K+ in</p> Signup and view all the answers

    What is the primary function of the light reactions in photosynthesis?

    <p>To generate ATP and NADPH</p> Signup and view all the answers

    In the context of metabolism, anabolic pathways:

    <p>Involve the synthesis of complex molecules</p> Signup and view all the answers

    Which compound is the principal electron donor in redox reactions?

    <p>Water</p> Signup and view all the answers

    What is the relationship between an enzyme and its substrate?

    <p>The substrate binds to the enzyme's active site</p> Signup and view all the answers

    Which molecule is produced during the light reactions of photosynthesis and used in the Calvin cycle?

    <p>ATP</p> Signup and view all the answers

    Which process by which green plants and some other organisms use sunlight to synthesize foods is called?

    <p>Photosynthesis</p> Signup and view all the answers

    What is a cofactor?

    <p>A non-protein chemical compound that assists enzyme function</p> Signup and view all the answers

    9

    <p>Chloroplast stroma</p> Signup and view all the answers

    What is the role of an enzyme's active site?

    <p>To bind the substrate and lower the activation energy</p> Signup and view all the answers

    The ultimate source of energy for most life on Earth is:

    <p>The sun</p> Signup and view all the answers

    What is the primary purpose of ATP in cellular processes?

    <p>To provide energy for cellular activities</p> Signup and view all the answers

    What is the significance of the Law of Conservation of Energy in biological systems?

    <p>It governs the principle that energy cannot be created or destroyed in biological processes</p> Signup and view all the answers

    Which molecule acts as a primary carrier of electrons during cellular respiration?

    <p>NAD+ (Nicotinamide adenine dinucleotide)</p> Signup and view all the answers

    What role do coenzymes play in biological systems?

    <p>They serve as electron carriers or precursors for electron carriers</p> Signup and view all the answers

    What is the main function of the Calvin cycle in photosynthesis?

    <p>Fixing carbon dioxide</p> Signup and view all the answers

    In which process is substrate-level phosphorylation known to occur?

    <p>Both b and c</p> Signup and view all the answers

    What is the primary function of fermentation in biological systems?

    <p>Produce ATP in the absence of oxygen</p> Signup and view all the answers

    Which process is primarily responsible for the oxygenation of Earth's atmosphere?

    <p>Photosynthesis</p> Signup and view all the answers

    What does the enzyme Rubisco (Ribulose-1,5-bisphosphate carboxylase/oxygenase) do in the Calvin cycle?

    <p>Converts carbon dioxide into sugar molecules</p> Signup and view all the answers

    What is the primary function of the light reactions in photosynthesis?

    <p>To provide energy for the Calvin cycle</p> Signup and view all the answers

    What does the conversion of glucose to two molecules of pyruvate during glycolysis result in?

    <p>4 ATP and 2 NADH</p> Signup and view all the answers

    What is the role of vitamins in the cell?

    <p>Coenzymes or precursors for coenzymes</p> Signup and view all the answers

    What principle describes that energy cannot be created or destroyed, but can only be transformed from one form to another?

    <p>The first law of thermodynamics</p> Signup and view all the answers

    Which process can move substances from a lower to a higher concentration across the plasma membrane?

    <p>Active transport</p> Signup and view all the answers

    What is the main function of the carbohydrates attached to the external surface of the plasma membrane?

    <p>Mediating cell-cell interactions</p> Signup and view all the answers

    What is the role of membrane receptors in signal transduction?

    <p>To receive and transmit signals to the cell's interior</p> Signup and view all the answers

    The sodium-potassium pump is an example of:

    <p>An active transporter</p> Signup and view all the answers

    What are glycolipids and glycoproteins primarily involved in?

    <p>Cell-cell recognition</p> Signup and view all the answers

    Desmosomes are cell structures that are particularly important for:

    <p>Providing mechanical strength to tissues</p> Signup and view all the answers

    What is the primary function of protein channels within the cell membrane?

    <p>To facilitate the movement of molecules across the membrane</p> Signup and view all the answers

    Cell membranes are primarily composed of:

    <p>Phospholipids and proteins</p> Signup and view all the answers

    What is the primary function of receptors in the plasma membrane?

    <p>Transmitting signals from outside to inside the cell</p> Signup and view all the answers

    Lipid rafts in the plasma membrane are:

    <p>Areas rich in specific types of lipids and proteins</p> Signup and view all the answers

    What is the role of integral membrane proteins?

    <p>Transporting ions across the membrane</p> Signup and view all the answers

    What is the term that describes the movement of molecules down their concentration gradient?

    <p>Diffusion</p> Signup and view all the answers

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