UPDATED GCU BIO202 EXAM 1 VERIFIED SOLUTIONS 2023/2024

hormones promote body homeostasis - ANSWER Hormones react on each other and help keep homeostasis in an organism. Hormones released from one gland can tell other glands to make different hormones Endocrine system - ANSWER -uses hormones -effects many organs -is slower and longer lasting nervous system - ANSWER -uses electricity and chemicals -has a specific effector organ -faster neurotransmitter - ANSWER a chemical compound released by one neuron to affect the trans membrane potential of another hormone - ANSWER -A compound that is secreted by one cell and that travels through the bloodstream to affect the activities of cells in another portion of the body. -Turn existing enzyme "on" or "off" negative feedback and its role in regulating blood levels of the various hormones - ANSWER -response to changed body condition -ex. signals tell body to make changes that will bring back to normal level. -once back to normal, will turn off. Three types of intercellular communication pathways that enable the body to maintain homeostasis - ANSWER -direct communication -paracrine -endocrine Direct communication - ANSWER occurs between 2 types of the same cell paracrine - ANSWER Most common. uses chemical signals to transfer from cell to cell within single tissue Endocrine - ANSWER slower. release into bloodstream. Alters metabolic activities. Target organ - ANSWER specific cells that posessess receptors needed to bind and "read" hormonal messages Lock and Key system - ANSWER Hormones fit receptors on "target cells" Three ways in which hormones are classified - ANSWER -amino acid derivatives -peptide hormones -lipid derivatives (steroid hormones) Free hormones - ANSWER -less than 1 hour function -diffuse out of bloodstream -brokendown/absorbed by kidney/liver -broken down by enzymes Protein bound hormones - ANSWER -Remain much longer -enter bloodstream Lipid soluble hormone - ANSWER -steroid hormone enters cell and binds to intracellular receptor -enters nucleus -binds to hormone response element -initiates transcription of the gene to mRNA -mRNA directs protein synthesis Lipid insoluble hormone - ANSWER -nonsteroid hormone enters receptor protein (first messenger) -receptor protein enters activated enzyme and generates ATP and cAMP (Second messenger) -glycogen breaks down Process of amplification - ANSWER -the binding of a small number of hormones to membrane receptors -leads to thousands of second messangers in cell -magnifies effect of hormone on target cells Down regulation - ANSWER -Presence of hormone triggers decrease in number of hormone receptors -when levels are high, cells become less sensitive