Exam 1 - bio

biology

study of living organisms an their interactions with one another and their environments

science

knowledge that covers general truths or the operation of general laws

scientific method

method of research with defined steps that include experiments with careful observation

basic science

seeks to expand knowledge regardless of short term application

applied science

use of science to solve immediate problems

prokaryotes

single-celled organisms lacking membrane bound intracellular organelles

atom

smallest unit of matter that retains all chemical properties of an elements

nucleus

center of the atom that contains protons and neutrons

proton

positively charged subatomic particle

neutron

subatomic particle with a neutral charge

electron

negatively charged subatomic particle

atomic number

number of protons

atomic mass

the mass of the atom, roughly equal to number of protons and neutrons

isotopes

element with the same number of protons but differing numbers of neutrons

radioisotopes

unstable isotopes that emit neutrons, protons and electrons

valence shell

outermost shell of an atom

electron orbitals

complex shapes that describe how electrons are spatially distributed around the nucleus

chemical reactions

changes in distribution of electrons between atoms

reactants

substances used at the beginning of a reaction

products

substances formed at the end of the reaction

chemical bond

the attractive force that links atoms together to form molecules and compounds

chemical formula

give the number of each type of atom in a molecule

structural formula

shows arrangement of atoms in a molecule

when ionic compounds are formed

metals lose electrons and nonmetals gain electrons

ion

atom with a positive or negative charge

anion

A negatively charged ion

cation

A positively charged ion

salts

ionic compounds made of anion and cations

polar covalent bonds

electrons are unequally shared by atoms and attracted to one nucleus than another

non polar covalent bonds

electrons are equally shared by atoms

hydrogen bond

interaction between the partial positive of hydrogen and partial negative of a more electronegative atom

van der waal interactions

weak attractions between two or more molecules due to changes in electron density

water makes up

60-70% of the human body

the chemical bonds between hydrogen and oxygen are...

polar covalent bonds

heat capacity

the amount of heat required to raise the temperature of one gram of substance by one degree celsius

heat of vaporization

amount of energy required to change one gram of liquid into gas

dissociation

atoms break off from compounds and form ions

cohesion

water molecules at the liquid-gas interface stick together due to hydrogen bonding

surface tension

capacity of a substance to withstand being ruptured when placed under tension or stress

adhesion

an attraction between water molecules and other molecules

capillary action

the combined force of attraction among water molecules and with the molecules of surrounding materials

acidity (acidic)

high H+ concentrations

alkalinity (basic)

high OH- concentrations

buffers

maintain internal pH by resisting changes in pH

hydrocarbons

carbon + hydrogen

isomer

molecules with the same chemical formula but differing arrangement of atoms or types of bonds between atoms

structural isomer

have different covalent arrangement of atoms

geometric isomer

different arrangement of atoms around a double bond

enantiomers

molecule share chemical formulas and bonds but differ in 3D placement of atoms; they are mirror images of each other

trans configuration

hydrogen are on opposite sides

cis configuration

hydrogens are on the same side

functional groups

groups of atoms within a molecules that confer consistent specific properties to these molecules

monomer

macromolecules consisting of individual subunits

polymers

three or more monomers that are linked together

dehydration synthesis

two molecules are joined together at their hydroxyl groups and water is released as a result (absorption of energy)

hydrolysis

breaking down of a polymer into monomers via that addition of water (release of energy)

enzymes

bio molecule that can catalyze reactions

aldoses

carbonyl group is at the end of the carbon chain

ketoses

carbonyl group in the middle of the carbon chain

polysaccharides

long chain of monosaccharides

starch

energy storage in plants

cellulose

cell walls of plants

chitin

cell walls of fungi and exoskeletons of arthropods

glycogen

energy storage in animals

hydrophobic

dislikes water

hydrophilic

likes water

non-polar molecules are

hydrophobic

polar molecules are

hydrophilic

ester linkage

the bond between fatty acids

saturated fatty acid

no carbon-carbon double bonds, exist as solids at room temperature

unsaturated fatty acid

one or more carbon-carbon double bonds, exist as liquids at room temperature

cis fatty acids

hydrogens are on the sam side of double bond, liquid at room temperature (bent)

trans fatty acids

hydrogens are on opposite sides of double bond

phospholipid

molecule with two fatty acids and a modified phosphate groups with glycerol backbone

amphipathic

containing a hydrophobic and hydrophilic region

catabolic

breakdown substrates

anabolic

build molecules

catalyst

affect the rate of a reaction

digestive enzymes

aid in digestion of food via catabolizing nutrients into monomers

transport proteins

carry substances in the blood or lymph throughout the body

structural proteins

construct different structure for support

hormones

coordinate the activity of body systems

defense proteins

protect the body from foreign pathogens

contractile proteins

aid in muscle contraction and movement

storage proteins

provide nourishment in early development of embryos

amino acids

monomers that make up proteins

peptide bond

bonds between amino acid monomers (formed via dehydration synthesis)

polypeptide

chain of amino acids joined together

protein

polypeptide with a biological function

primary structure

sequence of amino acids in a polypeptide

secondary structure

local folding of the polypeptide

alpha helix

formed via hydrogen bonds between oxygens in carbonyl groups and amino acids

beta pleated sheet

hydrogen bonding between atoms on the backbone of the polypeptide chain

tertiary structure

three dimensional structure of a polypeptide

quaternary structure

interactions between several polypeptides that make up a protein

denaturation

changes in protein structure that lead to change in functions due to changes in pH or temperature

nucleic acids

constitute the genetic material of living organism

chromatin

complex of DNA and histone proteins

chromosomes

threadlike structures containing tightly wound and pack chromatin

messenger RNA (mRNA)

intermediary nucleic acid that leaves the nucleus with instructions for protein synthesis (transcription)