bio 81

duodenum

first portion of the small intestine where chyme from the stomach mixes with digestive juices from the pancreas, liver, bladder, and the small intestine

bile

aids in digestion and absorption of fats

emergent properties

the arrangement and interaction of parts within a system

reductionism

reduction of complex systems to simpler components that are more manageable to study

negative feedback

more product accumulates, the process that creates it slows and less of the product is produced

positive feedback

as more product accumulates, the process that creates it speeds up and more of the product is produced

polar covalent bonds

one atom is more electronegative. atoms do not share the electron equally

van der waals interactions

attractions between molecules that are close together as a result of hot spots

cohesion

particles of the same substance stick together

adhesion

attractions of particles of different substances

heat of vaporization

the heat a liquid must absorb for 1g to be converted to gas

evaporative cooling

as liquid evaporates, its remaining surface cools

colloid

stable suspension of fine particles in a liquid

buffers

substances that minimize changes in concentrations of H+ and OH- in a solution

isomers

compounds with same molecular formula but different structures and properties

structural isomers

different covalent arrangements of atoms

cis-trans isomers

same covalent bonds, differ in spatial arrangements

enantiomers

isomers that are mirror images of each other

polymer

long molecule consisting of many similar building blocks

monomers

small building-block molecules

dehydration reaction

two monomers bond together through the loss of water

hydrolysis

two monomers broken apart through the formation of a water molecule

monosaccharides

simplest carbohydrates (CH2O)

trioses

3 carbon sugar

pentoses

5 carbon sugars

hexoses

6 carbon sugars

disaccharide

forms when a dehydration reaction joins two monosaccharides

glycosidic linkage

chemical bond that joins a carbohydrate molecule to another group

polysaccharides

polymers of sugars, have storage and structural roles

starch

storage of polysaccharide plants, consists of glucose monomers

glycogen

storage polysaccharide in animals

chitin

provides structural support for cell walls of many fungi

glyverol

3 carbon alcohol with a hydroxyl group attached to each carbon

fatty acid

triacyglycerol

3 fatty acids joined to glycerol by an ester linkage

saturated fatty acids

have the max number of hydrogen atoms possible and no double bonds, solid at room temp

unsaturated fatty acids

have one or more double bonds, liquid at room temp

hydrogenation

the process of converting unsaturated fats to saturated fats by adding hydrogen

phospholipid

2 fatty acids and a phosphate group attached to glycerol

steroids

lipids characterized by a carbon skeleton consisting of four fused rings

cholesterol

steroid essential in animal cell membranes

enzymes

protein that acts as a catalyst to speed up chemical reactions

amino acids

organic molecules with carboxyl and amino groups

polypeptides

unbranched polymers built from the same set of 20 amino acids

primary structure of a protein

the sequence of amino acids, determined by inherited genetic info

secondary structure

has coils and folds that result from hydrogen bonds

tertiary structure

interactions between R groups

disulfide bridges

strong covalent bonds that reinforce the proteins structure

quaternary structure

two or more polypeptide chains

collagen

fiborous protein that consists of 3 polypeptides

sickle-cell disease

inherited blood disorder that results from a single amino acid substitution

chaperonins

protein molecules that assist the proper folding of other proteins

cell fractionation

takes cells apart and separates the major organelles from one another

plasma membrane

selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell

nuclear envelope

encloses the nucleus separating it from cytoplasm, double membrane

smooth ER

lacks ribosomes, synthesizes lipids, metabolizes carbs, detoxifies drugs and poisons, store calcium ions

rough ER

has ribosomes that secrete glycoproteins, distributes transport vesicles, membrane factory

golgi apparatus

consists of flattened membranous sacs called cisternae, modifies products of the ER, manufacture macromolecules, sorts and packages materials into transport vesicles

lysosome

digests macromolecules, uses enzymes to recycle the cell’s own organelles (autophagy)

contractile vacuoles

pump excess water out of cells

central vacuoles

hold organic compounds and water

endosymbiont theory

early eukaryotic cell ancestor engulfed a prokaryotic cell which merged into a single celled eukaryotic cell with a mitochondrion, one of these cells took up a photosynthetic prokaryote, becoming the ancestor of cells that contain chloroplasts

cristae

give a larger surface area for enzymes to synthesize ATP

thylakoids

membranous sacs, stacked to form granum

stroma

internal fluid of chloroplasts

peroxisomes

produce hydrogen peroxide and convert it into water

cytoskeleton

network of fibers extending throughout the cytoplasm, organizes the cells structures and activities, helps support the cell and maintain the shape

microtubules

hollow rods that shape the cell, guide movement or organelles, separates chromosomes during cell division, control the beating of cilia and flagella

basal body

anchors cilium or flagellum

dynein

drives the bending movement of cilium or flagellum

microfilaments

solid rods that bear tension, resisting pulling forces within the cell

cortex

3D network inside the plasma membrane that helps support the cells shape

pseudopodia

extend and contract through the reversible assembly and contration of actin subunits into micrrofilaments

cytoplasmic streaming

circular flow of cytoplasm within cells

intermediate filaments

support cell shape and fix organelles in place

plasmodesmata

channels that perforate plant cell walls, water and small solutes can pass from cell to cell

tight junctions

membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid

desmosomes

(anchoring junctions) fasten cells together into strong sheets

gap junctions

(communicating junctions) provide cytoplasmic channels between adjacent cells.

amphipathic molecules

contain hydrophobic and hydrophilic regions

fluid mosaic model

a membrane is fluid structure with a mosaic of various proteins embedded in it

peripheral proteins

bound to the surface of the membrane

integral proteins

penetrate the hydrophobic core

transmembrane proteins

integral proteins that span the membrane

glycolipids

membrane carbohydrates that are covalently bonded to lipids

glycoproteins

membrane carbohydrates that are covalently bonded to proteins

transport proteins

allow the passage of hydrophilic substances across the membrane

channel proteins

have hydrophilic channel that certain molecules or ions use as a tunnel

aquaporins

channel proteins that facilitate the passage of water

carrier proteins

bind to molecules and change shape to shuttle them across the membrane

diffusion

the tendency for molecules to spread out evenly into the available space

osmmosis

the diffusion of water across a selectively permeable membrane

tonicity

the ability of a surrounding solution to cause a cell to gain or lose water

isotonic solution

solute concentration is the same inside and out the cell

hypertonic solution

solute concentration is greater than that inside the cell, cell loses water

hypotonic

solute concentration is less than that inside the cell, cell gains water

osmoregulation

the control of solute concentrations and water balance, a necessary adaptation for life

plasmolysis

in a hypotonic environment, plant cells lose water, eventually making the membrane pull away from the wall

facilitated diffusion

transport proteins speed the passive movement of molecules across the plasma membrane