BIOC 601: Molecular Aspects of Cell Biology

Neurotransmitters are chemical messengers that transmit signals across synapses by binding to receptors on the postsynaptic neuron.

Receptors are proteins on the postsynaptic membrane that bind neurotransmitters, initiating a response in the neuron.

Transport proteins help in the reuptake of neurotransmitters from the synaptic cleft back into the presynaptic neuron.

<p>Active transport requires energy to move neurotransmitters against their concentration gradient, while passive transport does not.</p> Signup and view all the answers

<p>Receptor-ligand interactions are critical for signal transduction, as they determine how cells respond to external stimuli.</p> Signup and view all the answers

<p>Gap junctions are specialized intercellular connections that allow direct communication between neighboring cells by facilitating the passage of ions and small molecules.</p> Signup and view all the answers

<p>Slow signaling mechanisms involve long-term changes in gene expression and cellular function, typically mediated by intracellular receptors.</p> Signup and view all the answers

<p>The cytoskeleton is a dynamic network of fibers that provides structural support, facilitates cellular movement, and organizes cellular components.</p> Signup and view all the answers

<p>Microfilaments, intermediate filaments, and microtubules.</p> Signup and view all the answers

<p>The cytoskeleton enables cell movement by facilitating cilia and flagella movement and allowing shape changes during cell division and migration.</p> Signup and view all the answers

<p>Spectrin provides structural support and maintains cell shape by forming a meshwork beneath the plasma membrane.</p> Signup and view all the answers

<p>Active transport requires energy to move molecules against their concentration gradient, while passive transport does not require energy and moves molecules down their concentration gradient.</p> Signup and view all the answers

<p>Microtubules serve as tracks for the movement of organelles and other cellular components within the cell.</p> Signup and view all the answers

<p>The cytoskeleton helps organize and separate chromosomes during mitosis.</p> Signup and view all the answers

<p>G-protein coupled receptors have a seven-transmembrane domain structure and activate intracellular G-proteins upon ligand binding.</p> Signup and view all the answers

<p>Gap junctions allow for direct cytoplasmic transfer of ions and small molecules between adjacent cells, facilitating coordinated cellular responses.</p> Signup and view all the answers

<p>The cytoskeleton provides mechanical support, helping the cell maintain its shape and structural integrity.</p> Signup and view all the answers

<p>Abnormal cell-cell communication can lead to diseases such as cancer, where the signaling pathways that regulate cell growth and apoptosis become disrupted.</p> Signup and view all the answers

<p>Microfilaments, primarily composed of actin, are involved in muscle contraction.</p> Signup and view all the answers

<p>The cytoskeleton plays a role in signal transduction by facilitating intercellular communication and coordination.</p> Signup and view all the answers

<p>Graves' disease is caused by abnormal signaling in the thyroid gland, leading to hyperthyroidism due to overstimulation by antibodies.</p> Signup and view all the answers

<p>The cytoskeleton aids in the development of vacuoles by providing support and structure during vacuole formation.</p> Signup and view all the answers

<p>The electrical properties of membranes are primarily determined by the distribution of ions across the membrane and the permeability of the membrane to those ions.</p> Signup and view all the answers

<p>The inositol phospholipid signaling pathway generates second messengers, such as inositol trisphosphate (IP3) and diacylglycerol (DAG), leading to the release of calcium ions and activation of protein kinases.</p> Signup and view all the answers

<p>Intermediate filaments provide structural support for microfilaments and microtubules, helping to maintain cell integrity.</p> Signup and view all the answers

<p>Spectrin contributes by forming a hexagonal arrangement alongside actin filaments, creating a scaffold that maintains plasma membrane integrity.</p> Signup and view all the answers

<p>Knocking out a or ß spectrin results in neurons that appear morphologically normal but exhibit reduced neurotransmission at the neuromuscular junction.</p> Signup and view all the answers

<p>Spectrin forms a meshwork that gives red blood cells their characteristic biconcave shape, crucial for their function.</p> Signup and view all the answers

<p>Spectrin subunits arrange into pentagonal or hexagonal structures, facilitating the formation of junctional complexes that enhance cell stability.</p> Signup and view all the answers

<p>The three main parts of a cell are the cell membrane, nucleus, and cytoplasm.</p> Signup and view all the answers

<p>Eukaryotic cells contain a defined nucleus, while prokaryotic cells lack a nucleus and have a nucleoid region.</p> Signup and view all the answers

<p>Plant cells have a cell wall for structure and support, and chloroplasts for photosynthesis, allowing them to produce their own food.</p> Signup and view all the answers

<p>Most cells are between 1 and 100 micrometres in size.</p> Signup and view all the answers

<p>The smallest known type of cell is mycoplasmas, with diameters as small as 0.2 μm.</p> Signup and view all the answers

<p>Actin forms microfilaments that are essential for various cellular processes including muscle contraction and cell motility.</p> Signup and view all the answers

<p>Mutations can lead to diseases by disrupting the normal production and function of actin, impairing cellular processes.</p> Signup and view all the answers

<p>Microtubules are polymers of alpha and beta tubulin that form hollow tubes, with a diameter of 23 to 27 nm.</p> Signup and view all the answers

<p>Microtubules provide structural support, facilitate intracellular transport, and are essential for mitosis.</p> Signup and view all the answers

<p>Intermediate filaments are made up of various proteins characterized by a central alpha-helical rod domain.</p> Signup and view all the answers

<p>Tensile strength is crucial for maintaining cellular integrity and stability under stress.</p> Signup and view all the answers

<p>Actin assists in cellular migration and contraction, which are vital for tissue repair during wound healing.</p> Signup and view all the answers

<p>Microtubules serve as tracks for motor proteins that transport organelles within the cell.</p> Signup and view all the answers

<p>Microfilaments are made of actin, microtubules are made of tubulin, and intermediate filaments are made of various proteins, each serving distinct structural and functional roles.</p> Signup and view all the answers

<p>Microtubules form the mitotic spindle, which is crucial for the separation of chromosomes during mitosis and meiosis.</p> Signup and view all the answers