Biology Final Vocabulary

Reductionism

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

Systems Biology

An approach to studying biology that aims to model the dynamic behavior of whole biological systems based on a study of the interactions among the system's parts.

Theory

implies a lack of knowledge or an educated guess

Homologous

same evolutionary origin but now differ in structure and function

Analogous

structures of different origin used for the same purpose

Phylogenetic trees

based on tracing origin of particular nucleotide changes to reconstruct an evolutionary history

DNA

deoxyribonucleic acid

Gene

discrete unit of information

Genome

entire set of DNA instructions

Matter

Anything that has mass and takes up space

Element

any substance that cannot be broken down to any other substance by ordinary chemical means

Mass

A measure of the amount of matter in an object

Weight

refers to force gravity exerts on substance

Cations

more protons than electrons

Anions

fewer protons than electrons

Isotopes

atoms of a single element that possess different numbers of neutrons

Half-Life

time it takes for ½ of the atoms in a sample to decay

Bohr Model

electrons in discrete orbits

Orbital

area around the nucleus where an electron is most likely found

Oxidation

loss of an electron

Reduction

gain of an electron

Valance Electrons

number of electrons in the outermost energy level

Inert (nonreactive) elements

have all 8 electrons

Octet Rule

atoms tend to establish completely full outer energy levels

Ionic Bonds

formed by attraction of oppositely charged ions

Nonpolar covalent bonds

equal sharing of electrons

Polar covalent bonds

unequal sharing of electrons

Reactants

original molecules

Products

molecules resulting from reaction

Cohesion

water molecules stick to other water molecules by hydrogen bonding

Adhesion

water molecules stick to other polar molecules by hydrogen bonding

Hydrophilic

water loving

hydrophobic

water fearing

Acid

any substance that dissociates in water (lower pH)

Base

combines in water (higher pH)

Buffer

substances that resists the changes in pH

Hydrocarbons

molecule consisting only of carbon and hydrogen

Functional groups

specific molecular groups that bond to carbon

Isomers

molecules with the same molecular or empirical formula

Structural isomers

differ in structure of C skeleton

Stereoisomers

differ in how groups attached

Chiral

4 unique groups attached

Polymer

built by linking monomers

Monomer

small, similar chemical subunits

Dehydration synthesis

the formation of large molecules by the removal of water

Hydrolysis

the breakdown of large molecules by the addition of water

Disaccharides

2 monosaccharides linked together by dehydration synthesis

Polysaccharides

long chains of monosaccharides

Helix

Coiled spiral

Sheet

Planar structure

Denaturation

protein loses its structure by unfolding and then also its function

Lipids

group of molecules with one main chemical characteristic

Cytoplasm

semifluid matrix of organelles and cytosol

Ribosomes

synthesize proteins

Plasma membrane

phospholipid bilayer

Cytoskeletons

influence shape of cell wall

Flagella

used for locomotion

Nucleus

repository of the genetic information

Plasmodesmata

specialized openings in their cell walls

Lipidomics

the number and biological function of lipids

Anchoring molecules

attach membrane protein to the membrane surface

Pores

extensive nonpolar regions within a transmembrane protein can create a pore through the membrane

Passive transport

movement of molecules through the membrane in which no energy is required

Osmosis

net diffusion of water across a membrane toward a higher solute concentration

Hypertonic solution

higher solute concentration

Hypotonic

lower solute concentration

Osmotic pressure

force needed to stop osmotic flow

Thermodynamics

branch of chemistry concerned with energy changes

Entropy

degree of randomness

Gibbs free energy

energy available to do work

Enthalpy

sum of entropy and gibbs free energy

Catalysts

substances that influence chemical bonds in a way that lowers activation energy

Inhibitor

substance that binds to enzyme and decreases it's activity

Electron Transport Chain (ETC)

series of membrane-bound electron carriers

Chemiosmosis

accumulation of protons in the intermembrane space drives protons into the matrix via diffusion

Photosynthesis

energy from the sun is captured through the process of...

Grana

stacks of flattened sacs of thylakoid membrane

Stroma lamella

Connect grana

Stroma

semiliquid surrounding thylakoid membrane

Pigments

molecules that absorb light energy in the visible range

Photon

particle of light

Photoelectric effect

removal of an electron from a molecule of light

Absorption spectrum

range and efficiency of photons a molecule is capable of absorbing

Plasmids

small, circular DNA molecules that obtain only a few genes and are capable of self

Bacterial conjunction

bacterial cells exchange plasmids via their sex pili

Horizontal gene transfer

the exchange of genetic material allows bacteria to evolve new features

Karyotype

array of chromosomes in an individual organism

Homologous

Pair of chromosomes

Homologue

Individual chromosome

Chromatin

complex of DNA and protein (chromosomes are composed of this) *40% DNA and 60% protein*

Nucleosomes

unit of a chromosome, consisting of a length of DNA *negatively charged* coiled around the histone (H2A, H2B, H3, H4)*positively charged*

Territories

contain individual chromosomes

Compartments

exist within each chromosome

TADs

loops of DNA in nucleosomes

Euchromatin

lightly packed form of chromatid *active*

Heterochromatin

condensed form of chromatid *not active*

Cohesion proteins

holds together 2 identical DNA molecules

Monohybrid cross

a cross that follows only a single trait with two variations

F1

first filial generation

Allele

alternative form of a gene