BIOLOGY 220 NOTES.docx - BIOLOGY 220 NOTES Chapter 1 Major Themes of A and P(pg 1 Homeostasis ability to maintain stable internal condition-maintained

BIOLOGY 220 NOTES.docx - BIOLOGY 220 NOTES Chapter 1 Major...

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BIOLOGY 220 NOTES Chapter 1: Major Themes of A and P (pg. 1) Homeostasis- ability to maintain stable internal condition -maintained by negative feedback and positive feedback *Negative Feedback Mechanisms digress from standard and then return to the standard. Capillaries- only place things enter and exit in cardiovascular because so thin (Average level of glucose in plasma of blood is 90 mg/100 ml of blood) -Right Side of Diagram - high sugar food (Dr. Pepper and a Snickers)—digress from the standard in the direction of more— BETA cells (sensor) from the Islet of Langerhans in pancreas detect movement >90 mg— insulin first messenger—target cell absorbs glucose from plasma— glucose used in cellular respiration (products are ATP + H2O + CO2) -Left Side of Diagram - haven’t eaten—glucose level too low ALPHA cells detect decreasing—release glucagon— glucagon goes to target cell and tells it to release glucose, raising the glucose blood level back to standard. Other examples- calcium too high—THYROCALCITONIN; calcium too low-- PARATHORMONE *Positive Feedback digress from standard more and more- shut off (don’t go back to standard) - must have an opportunity to stop Blood clotting (can’t get certain birth control with family history of blood clotting disorder- continue clotting until you die) Childbirth- OXYTOCIN—more pressure, more oxytocin, more pressure, more oxytocin CATASTROPHIC ENDINS UNLESS SOMETHING INTERVENES 1
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BIOLOGY 220 NOTES Chapter 2: The Chemistry of Life (pg. 41) Elements- simplest form of matter to have unique chemical properties Ions - charged particles with uneven numbers of protons and electron -can consist of a single atom with a positive or negative charge or as large as a protein with many charges on it --Gains electrons for a negative charge- ANION vs loses electrons for a positive charge- CATION Ions with opposite charges are attracted to each other and tend to follow each other throughout the body. Electrolytes- substances that ionize in water (ACIDS, BASES, OR SALTS) and form solutions capable of conducting electricity --important for chemical reactivity (calcium phosphate incorporated into bone), osmotic effects (water content and distribution), and electrical effects (muscle and nerve function) Free Radicals- chemical particles with odd number of electrons --produced by some normal metabolic reactions (ATP-producing oxidation in MITOCHONDRIA) --combine with fats, proteins, and DNA- converting them to free radical and triggering chain reactions (can cause cancer and death of heart tissue) -- ANTIOXIDANT s a chemical that neutralizes a FREE RADICAL. BONDS ---Molecules- two are more atoms united by chemical bond --- Compounds- molecules composed of 2 or more elements A molecule is held together by forces called CHEMICAL BONDS.
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