UConn Bio Unit 1

Evolution

the process of change over time that has transformed life on earth

Biology

Scientific study of life

Properties of Life

Order, Regulation, Energy Processing, Growth and Development, Reproduction, Response to Environment, Evolutionary Adaptation

Levels of Biological Organization

Biosphere, Communities, Populations, Organisms, Ecosystems, Organs and Organ Systems, Tissues, Cells, Organelles, Atoms and Molecules

Emergent Properties

result from the arrangement and interaction of parts within a system (ex. a functioning bicycle emerges only when all the parts are put together correctly)

Reductionism

The reduction of complex systems to simpler components, more manageable to study

Systems Biology

Constructs models for the dynamic behavior of whole biological systems

Dynamics of an Ecosystem

Two Major Processes: Cycling of Nutrients: when plants return the materials they acquired back to the soil Flow of Energy: From sunlight to producers to consumers

Work

requires a source of energy, energy flows through an ecosystem usually entering as light and exiting as heat

Structure and Function

are closely related, form fits function (ex. leaf is thin and flat in order to maximize capture of light for photosynthesis)

Cell

basic unit of life, lowest level of organization, can perform all necessary activities required for life all cells are enclosed in a membrane and use DNA as their genetic info

Eukaryotic Cell

Has nucleus, membrane enclosed organelles

Prokaryotic Cell

simpler + smaller, doesn't have a nucleus or membrane enclosed organelles, archaea and bacteria are prokaryotes

DNA

DNA is the substance of genes, chromosomes contain most of a cells genetic info in form of DNA, each chromosome has one long DNA molecule with thousands of genes, controls development and maintenance of organisms

Genes

Unit of inheritance that transfer genetic info from parent to offspring

Double Helix

Format of every DNA molecule, two long chains wrapped, each chain is made up of monomers called nucleotides (A,C,T,G)

Central Dogma

DNA → RNA → proteins (required for production)

Genome

an organisms entire set of genetic instructions

Bioinformatics

The use of computational tools to process larges amounts of data

Negative Feedback

Reverses trend, as more of a product accumulates negative feedback slows and decreases production of that product

Positive Feedback

Accelerates a trend, as more of a product accumulates positive feedback speeds and increases production of that product

Taxonomy

branch of bio that names and classifies species into groups/categories

Classifiying Life in order

Species, Genus, Family, Order, Class, Phylum, Kingdom, Domain

Three Domains of Life

Domain Eukarya: eukaryotes (nucleus) Domain Bacteria + Domain Archaea: prokaryotes (no nucleus)

Multicellular Kingdoms

Animalia, Fungi, Plantae Protista

Unity underlies the diversity of life

DNA is the universal genetic language common to all organisms unity is evident in many features of cell structure

Data

recorded observations/info Qualitative: descriptive Quantitative: measurable

Hypothesis

tentative answer to a question, must be testable and falsifiable

Matter

anything that takes up space and has mass, made up of elements

Element

Substance that cannot be broken down into another substance, 25 of 92 are essential to life, each consists of unique atoms

Compound

Substance consisting of 2 or more elements in a fixed ratio (table salt: sodium and chlorine)

What makes up 96% of living matter?

carbon, oxygen, hydrogen, nitrogen

Trace Elements

elements required by organisms for life in minute quantities

Atom

smallest unit of matter that retains the properties of an element, composed of subatomic particles: Nuetrons - no electrical charge Electrons - negative charge Protons - positive charge

Atomic Nucleus

made up of protons and nuetrons, electrons form cloud around this

Atomic Number

number of protons in a nucleus

Mass number

sum of protons and nuetrons

Atomic Mass

total mass of an atom, approximated by the mass number

Isotopes

two atoms of the same element that contains a different number of nuetrons

Radioactive Isotopes

isotopes that decay and give off particles and energy

Energy

capacity to cause change

Chemical Behavior of an atom is...

dependent by the distribution of electrons in electron shells, mostly valence electrons

Valence Electrons

Electrons in the outermost shell

Orbital

3D space where an electron is found 90% of the time

Atoms with incomplete valence shells...

can share or transfer valence electrons to each other to become stable

Chemical bonds

attractions that allow atoms to share and transfer valence electrons

Covalent Bond

sharing of valence electrons by two atoms, can form between atoms of the same or different elements

Molecule

consists of two or more atoms held together by covalent bonds

Single Covalent Bond

sharing of one pair of valence electrons

Double Covalent Bond

sharing of two pairs of valence electrons

Structural Formula/Molecular Formula

notation used to represent atoms and bonding ex. H-H can be further abbreviated by molecular formula ex. H2

Valence

bonding capacity, max number of covalent bonds an atom can have

Electronegativity

the atoms attractions for electrons in a covalent bond, the more electronegative an atom is the more strongly is pulls electrons

Nonpolar Covalent Bond

a covalent bond in which the atoms share the electron equally

Polar Covalent Bond

a covalent bond in which the atoms share the electron unequally, unequal sharing of electrons results in a negative or positive charge for each molecule or atom

Ion

charged atom or molecule

Cation

positively charged ion

Anion

negatively charged ion

Ionic Bond

an attraction between a cation and an anion

Salts

aka ionic compounds, compounds formed as result of ionic bonds

Hydrogen Bond

forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom, in living cells the electronegative partners are usually oxygen or nitrogen atoms

Van der Waal's interactions

attractions between molecules that are close together as a result of the charges (charges from asymmetrically distributed electrons) ex. molecules between a wall and gecko's toes hairs

Polar Molecule

molecule where the opposite ends have opposite charges ex water

Water's Four Properties

cohesive behavior, ability to moderate temperature (high specific heat), expansion upon freezing, versatility as a solvent

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances

Surface Tension

measure of how hard it is to break the surface of a liquid

High Specific Heat

A property of water. Water can absorb lots of heat before changing temperature

Kinetic Energy

the energy of motion

Heat

measure of the total amount of kinetic energy due to molecular motion

Temperature

measures intensity of heat due to average kinetic energy of molecule

Calorie

Amount of energy needed to raise temperature 1 gram of water 1 degree C

Kilocalorie (Calorie)

The amount of energy needed to raise 1 kilogram of water 1 degree Celsius.

Specific Heat

The amount of energy required to change the temperature of 1 gram of a substance by 1 degree celcius, high specific heat=stable

Hydrogen bonds breaking + forming

Heat is released when hydrogen bonds form, heat is absorbed when hydrogen bonds break

Heat of Vaporization

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

Evaporative Cooling

The process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from the liquid to the gaseous state.

Why does ice float?

hydrogen bonds are more ordered in ice than water making ice less dense, water reaches greatest density at 4 degrees Celsius

Solution

liquid that is a homogenous mixture of substances

Solvent

dissolving agent of a solution

Solute

substance that is dissolved

Aqueous Solution

water is the solvent in a solution

Hydrophilic Substance

substance that has an affinity for water

Hydrophobic Substance

substance that doesn't have an affinity for water

Colloid

stable suspension of fine particles in a liquid

Molecular Mass

sum of all masses of all atoms in a molecule

Moles

number of molecules are measure in moles, 1 mole = 6 x 10 to the 23

Molarity

number of moles of solute per liter of solution

Hydrogen Ion

a positively charged ion (H+) formed of a hydrogen atom that has lost its electron

Hydroxide Ion

OH-, hydrogen atom that lost the electron now has negative charge

pH

concentrations of H+ and
OH- can drastically affect the chemistry of a
cell, defined by the negative
logarithm of H+ concentration, written as
pH = -log [H+]

pH scale

describes how acidic or basic a solution is, 1-14, lower=more acidic, higher=more basic

Acid

any substance that increases the H+ concentration of a solution

Base

any substance that reduces the H+ concentration of a solution

Buffers

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

Acid Precipitation

Rain, snow, or fog with a pH below 5.6.

Carbon

unparalleled in its ability to form large, complex, and diverse molecules because each carbon atom makes 4 bonds, proteins, DNA, carbs are composed of carbon compounds, has four valence electrons (tetravalence), versatile, usually bonds with H, O, C, and N

Organic Chemistry

The study of carbon compounds (organic compounds), range from simple to complex, most contain hydrogen atoms

Electron Configuration

key to an atoms characteristics, determines chemical bonding (types + number of bonds an atom will form with other atoms)

Tetravalence

having 4 valence electrons, makes large and complex molecules possible