Term
| What is a paracrine signal? |
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Definition
| A paracrine signal is one that acts on cells near the secreting cell. |
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Term
| What is an autocrine signal? |
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Definition
| An autocrine signal acts on the secreting cell itself. |
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Term
| What is a general endocrine signal? |
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Definition
| An endocrine signal is one that travels through the bloodstream and creates a response in any target cell within the body. |
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Term
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Definition
| A pheromone is a chemical signal that is released from the body and communicates with other individuals in a species. |
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Term
| What are the three main class of of molecules that function as hormones in vertebrates? |
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Definition
| Polypeptides (water soluble), Amines (water soluble), and Steroids (lipid soluble) |
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Term
| What is the difference between the way that water soluble and lipid soluble hormones travel? |
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Definition
| Water soluble hormones travel in the bloodstream, and lipid soluble hormones diffuse across cell membranes. |
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Term
| What are the three key events induced by a hormone? |
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Definition
| Reception, Signal Transduction, and Response. |
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Term
| What are a couple things that hormone responses can induce? |
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Definition
| Enzyme activation or a change in gene expression. |
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Term
| Where does epinephrine come from, and how does it help you with a burst of energy? |
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Definition
| Epinephrine comes from the adrenal glands. It reaches the liver and binds to a GPCR, which then releases cAMP (second messenger) that induces an enzyme to speed up glycogen synthesis, which gives you glucose in your bloodstream for energy. |
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Term
| Describe the secretin response pathway. |
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Definition
| Low pH in the small intestine causes "S cells" from the duodenum to release the hormone "secretin" which targets the pancreas to release bicarbonate and increase pH in the duodenum. |
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Term
| What are two antagonistic hormones that regulate blood glucose concentration? |
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Definition
| Insulin and glucagon. Insulin decreases glucose concentration, whereas glucagon increases glucose concentration. Insulin promotes fat storage, whereas glucagon breaks down fat and protein. |
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Term
| What is an islet of Langerhans? |
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Definition
| An islet of Langerhans is a pancreatic cluster of cells that make insulin and glucagon. |
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Term
| What is diabetes and what is it marked by? |
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Definition
| Diabetes is a deficiency of insulin and is marked by elevated glucose levels. |
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Term
| What does the anterior pituitary gland do? |
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Definition
| The anterior pituitary gland releases hormones under regulation of the hypothalamus. |
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Term
| What does the posterior pituitary gland do? |
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Definition
| The posterior pituitary gland stores hormones made in the hypothalamus. |
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Term
| What is oxytocin and where is it stored? |
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Definition
| Oxytocin is a neurotransmitter that is stored in the posterior pituitary gland and stimulates milk release in mammary glands. This is an example of a positive feedback loop: suckling induces milk production, which causes more suckling. |
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Term
| What kind of feedback do hormone cascade pathways involve? |
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Definition
They involve negative feedback.
Hypothalamus --> anterior pituitary ---> endocrine tissue |
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Term
| What is a tropic hormone and what are four examples? |
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Definition
| A tropic hormone regulates endocrine cells and glands. Four tropic hormones: Thyroid-stimulating hormone (TSH), Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), and Adrenocorticotropic hormone (ACTH) |
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Term
| What are examples of two nontropic hormones? |
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Definition
| Prolactin (PRL) which stimulates lactation, and Melanocyte-stimulating hormone (MSH) which influences skin pigmentation and metabolism |
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Term
| What are examples of two nontropic hormones? |
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Definition
| Prolactin (PRL) which stimulates lactation, and Melanocyte-stimulating hormone (MSH) which influences skin pigmentation and metabolism |
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Term
| What two iodine-containing hormones does the thyroid gland produce? |
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Definition
| Triodothyronine and thyroxine, which stimulate metabolism and influence maturation. |
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Term
| What does parathyroid hormone (PTH) do? |
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Definition
| Parathyroid hormone raises calcium levels in the blood. It targets bones and calcium reabsorption in the kidney. Calcitonin has the opposite effect. |
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Term
| What is hyperthyroidism? Hypothyroidism? |
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Definition
| Hyperthyroidism is excessive secretion of hormones resulting in weight loss and high blood pressure. Hypothyroidism is low secretion of thyroid hormones causing lethargy and weight gain. |
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Term
| What are corticosteroids? Where are they released? What are two examples? |
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Definition
| These are released in response to stress from the adrenal cortex of the adrenal gland. Glucocorticoids influence glucose metabolism, and Mineralocorticoids affect salt and water balance. |
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Term
| What is the difference between type 1 and type 2 diabetes? |
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Definition
| Type 1 is insulin dependent in which the immune system kills pancreatic beta cells. Type 2 diabetes involves insulin deficiency or degradation of insulin receptors. |
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Term
| What are the names of cell junctions in animal cells and plant cells? |
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Definition
| Animals = Gap Junctions, Plants = Plasmodesmata |
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Term
| What is the difference between Conformation and Configuration? |
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Definition
| Conformation is the folding shape that depends on weak forces, Configuration depends on covalent bonds. |
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Term
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Definition
| The GPCR undergoes some extracellular activation, which activates a G-protein within a cell by displacing GDP with GTP. The activated G-protein dissociates from the receptor and binds to an enzyme, which sends out a cellular response. The enzyme then cleaves the G-protein, turning its GTP back into GDP and releasing a phosphate. |
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Term
| How do receptor tyrosine kinases work? |
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Definition
| They attach phosphates to tyrosine. When a signaling molecule binds to the receptors, the two polypeptides join together to make a dimer. This dimer then uses ATP to phosphorylate another kinase that changes the conformation of relay proteins which make a cellular response. |
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Term
| How does a ligand-gated ion channel work? |
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Definition
| A signaling molecule binds to a receptor as a ligand and then opens the gate to allow ions in or out. |
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Term
| What does a protein phosphatase do? |
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Definition
| A protein phosphatase remove phosphates from proteins. |
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Term
| What is a second messenger? Give 2 examples. |
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Definition
| A second messenger is a non-protein water soluble molecule or ion that diffuses throughout a cell. Examples: cAMP and Calcium. |
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Term
| What does Adenylyl Cyclase do? |
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Definition
| It converts ATP to cAMP in response to an extracellular signal. |
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Term
| How do you regulate cell metabolism? |
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Definition
| You inhibit adenylyl cyclase in GPCRs. |
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Term
| Where does signal transduction occur, and where does the response part of cellular signaling occur? |
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Definition
| Signal transduction occurs in the cytoplasm, and the response occurs in the nucleus. |
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Term
| Why are multistep pathways helpful? |
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Definition
| Multistep pathways can amplify a single and coordinate second messengers for more effective signaling. |
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Term
| Cell division is responsible for: |
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Definition
| reproduction, development, growth, repair |
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