Phys 261 - 1st half

midterm chapters

levels of organizations

atoms, molecules, cells, tissues, organs, organ systems, organisms

placebo

an inactive substance used in medical treatment

ions

an atom with a net positive or negative charge due to gain or loss of one or more electrons

anions

negatively charged ions

cations

postive charged ions

ionic bonds

attraction betwwen ions with oppositie charges

covalent bonds

atoms that share electrons; requires the most energy to make or break

covalent bonds are

nonpolar and polar molecules

nonpolar molecules

an even distribution of electrons

polar molecules

have regions of partial charge

3 types of noncovalent bonds

ionic bonds, hydrogen bonds, van der waals forces

hydrogen bonds

form between a hydrogen atom and a nearby oxygen, nitrogen, or fluorine atom

van der waals force

are weak, nonspecific attractions between atoms

saturated fatty acids

fatty acids that have no double bonds between carbons; thoroughly soaked with hydrogen

amino acids

proteins are polymers of smaller building block molecules consist of a carboxyl group and hydrogen

R group

makes amino acid react to other molecules in a unique way

primary structure

structure of proteins; the sequence of amino acids in a peptide chain

secondary structure

created primarily by hydrogen bonds between adjacent chains or loops

tertiary structure

the protein’s three-dimensional shape

quaternary structure

multiple subunits combine with noncovalent bonds; hemoglobin molecules are made from four globular protein subunits

nucleotides

important role in energy and info transfer; one or more phosphate group; 5 carbon sugar nitrogenous base

base-pairing

bases on one strand form hydrogen bonds with bases on the adjoining strand

nucleotide pairs

A, T, G, C

purines

nitrogenous base that have a double ring structure

pyramidines

nitrogenous bases that have a single ring

pH

concentration of free H+ in body fluids, or acidity

ph acidity

less than 7

ph basic/alkaline

greater than 7

protein specificity

the ability of a protein to bind to bind to a certain ligand of a group of related ligands

cell membrane

phospholipid bilayers; separates intracellular fluid from extracellular fluid

microvilli

increases cell surface area; supported by microfilaments

centrioles

made from microtubules; direct DNA movement during cell division

paracellular movement

movement of materials between cells transport through the junctions between adjacent cells

transcellular movement

must cross 2 cell membranes; uses active and passive transport comnination

energy

the capacity to work

1st law of thermodynamics

total amount of energy in the universe never changes

2nd law of thermodynamics

natural spontaneous processes move from state of order to disorder from nonrandomness to randomness

exergonic reaction

energy producing reaction

endergonic reactions

require a net input of energy; complex molecules are made from smaller molecules

competitive inhibitor

molecules that bind to the active site of the enzyme, preventing substrate binding

allosteric modulator

binds enzyme away from the binding site and change the shape of the active site

enzymes

catalysts for chemical reactions in living things

aerobic metabolism/respiration

metabolism that can proceed only in the presence of oxygen; metabolic pathways that yield the most ATP molecules

ATP production

the manufacturing of nucleotides containing 3 phosphate groups which are energy storage molecules; made to support the body’s metabolic activity

passive transport

the transportation of materials across a plasma membrane without using energy

active transport

the movement of materials through a cell membrane using energy

extracellular fluid

fluid outside the cell

resting membrane potential

\-70mV; the electrical charge of a neuron when it is not active

depolarization

change in a cell membrane potential from rest toward zero; becomes less negative

hyperpolarization

resting membrane potential becomes more negative

repolarization

return to resting membrane potential

paracrine signals

secreted by one cell and diffuse to adjacent cell

autocrine signals

act on the same cell that secreted them

down regulation

decrease in protein number or binding affinity that lessons response

up regulation

increase in protein number or binding affinity that increases the response of the target cell

types of hormones

peptides, amino acid-derived, and steroids

integrating center

the control center that evaluates incoming signal and decides on an appropriate response

positive feedback

a feedback loop in which the response reinforces the stimulus, triggering a vicious cycle of ever-increasing response

negative feedback

a homeostatic feedback loop designed to keep the system at or near a setpoint

endocrine responses

slow starting and long lasting

hypothalmic - anterior pituitary pathway thyroid release

hypothalamus releases thyrotropin-releasing hormone (TRH) → anterior pituitary releases thyroid stimulating hormone (TSH) → thyroid gland releases T3 and T4 → metabolism

hypothalamic - anterior pituitary pathway adrenal cortex release

hypothalamus releases corticotropin-releasing hormone (CRH) → anterior pituitary releases adrenocorticotrophic hormone (ACTH) → adrenal cortex releases cortisol to target tissues

hypothalmic - anterior pituitary pathway liver

hypothalamus releases growth hormone-releasing hormone (GHRH) → anterior pituitary releases growth hormone (GH) →liver releases insulin-like growth factors → bone and soft tissue growth

hypothalamic - anterior pituitary pathway endocrine cells of the gonads

hypothalamus releases gonadotropin-releasing hormone → anterior pituitary releases follicle-stimulating hormone (FSH), luteinizing hormone (LH) → endocrine cells of the gonads release androgens, estrogens, and progesterone to germ cells of the gonads

anterior pituitary

prolactine → breast → milk production

growth hormone (somatotropin)

anterior pituitary; peptide; liver; growth factor secretion/metabolism

corticotropin (adrenocorticotrophic)

anterior pituitary; peptide; adrenal cortex; cortisol release

thyrotropin, thyroid stimulating hormone

anterior pituitary; peptide; thyroid gland; thyroid hormone synthesis

follicle stimulating hormone

anterior pituitary; peptide; gonads; egg or sperm production

luteinizing hormone

anterior pituitary; peptide; gonads; sex hormone production

triidothyroinine and thyroxine

thyroid gland; amino acid derived; many tissues; metabolism, growth, and development

calcitonin

thyroid gland; peptide; bone; plasma calcium levels

parathyroid hormone

parathyroid gland; peptide; bone, kidney; regulates plasam Ca^2 and phosphate levels

thymosin, thymopoietin

thymus gland; lymphocytes; lymphocyte development

atrial natriuretic → peptide

heart (endocrine cells); kidneys; increases Na+ excretion

angiotensinogen → peptide

liver; adrenal cortex; blood vessels; aldosterone secretion and increases blood pressure

insulin-like growth factor → peptide

liver endocrine cells; many tissues; growth

gastrion, cholecystokinin, secretine → peptide

stomach and small intestines endocrine cells; GI tract and pancreas; assist digestion and absorption of nutrients

insuline, glucagon, somatostatin, pancreatic polypeptide

pancreas gland; metabolism of glucose and other nturients

aldosterone steroid

adrenal cortex; kidney; Na+ and K+ homeosotasis

cortisol steroid

adrenal cortex; stress response

androgens steroid

adrenal cortex; sex drive in females

epinephrine; norepinephrine amine

adrenal medulla; fight or flight response

erythropoietin peptide

kidney; bone marrow; red blood cell production

1\.25 dihydroxy-vitamin, D3 (calciferol) steroid

intestine; increases calcium absorption

vitamin D3 steroid

skin endocrine cells; intermediate form of hormone; precursor of 1.25 dihydroxy-vitamin D3

androgens steroid

testes; sperm production, secondary sex characteristics

inhibin peptide

testes; target anterior pituitary; inhibits FSH secretion

estrogen, progesterone steroid

ovaries; egg production, secondary sex characteristics

inhibin

ovaries; anterior pituitary; inhibits FSH secretion

relaxin peptide

ovaries; uterine muscle; relaxes muscle

neurotransmitter

chemical messengers

central nervous system

brain and spinal cord

parts of the peripheral nervous system (PNS)

sensory division; efferent division

parts of the autonomic nervous system (ANS)

visceral nervous system; sympathetic and parasympathetic; control smooth and cardiac muscles, exocrine glands, some endocrine glands; and some adipose tissue

scwann cells

cells in the PNS support and insulate axons by forming myelin

oligodendrocytes

cells in the CNS support and insulate axons by forming myelin

satellite cells

second type of PNS glial cell; nonmyelinating schwann cll

astrocytes

highly branched glial cells; make up half of all cells in the brain

ependymal cell

specialized cells that create a selectively permeable epithelial layer; they separate the fluid compartments of the CNS