Bio test unit 2 - chemistry in biology

Atoms

Building blocks of matter

Atomic Nucleus

Center of an atom where protons and neutrons are located.

Proton

A subatomic particle that has a positive charge and that is found in the nucleus of an atom

Neutron

A subatomic particle that has no charge and that is found in the nucleus of an atom

Electron

A subatomic particle that has a negative charge and is located in orbitals outside of the atom's nucleus.

Element

a pure substance that cannot be separated into simpler substances by physical or chemical means

Isotopes

Atoms of the same element that have different numbers of neutrons

Compound

a pure substance formed when two or more different elements combine

Covalent Bond

A chemical bond that forms when electrons are shared.

Molecule

A compound in which the atoms are held together by covalent bonds

Ion

An atom that has gained or lost one or more electrons.

Ionic Bond

an electrical attraction between two oppositely charged atoms or groups of atoms called ions

van der Waals forces

A slight attraction that develops between the positively and negatively charged regions of nearby molecules.

Atomic number

number of protons and electrons

Atomic mass

protons+neutrons=

Neutrons

Atomic mass-Atomic number=

electron orbitals

Each number on the right side of the periodic table block represents the number of

Things you can learn about an element from the periodic table

# of protons, electrons, neutrons, electron orbitals, mass of the element

stability

Atoms bond to achieve

8 electrons

How many electrons do most elements need to be stable?

Covalent bonds

Bonds that share electrons to achieve stability

Nonpolar covalent bonds

equal sharing of electrons

Polar covalent bonds

Unequal sharing of electrons

Electronegativity

The ability of an atom to attract electrons
Increases as you move up and across the periodic table

Unequal electronegativity

Leads to polar bonds and in extreme cases, ionic bonds

Nonpolar bonds

Difference of 0.5 or less

Polar bonds

Difference of 0.6-1.9

Ionic bonds

Difference of 2 or more

Negative ion/ anion

The element that accepts an electron

Positive ion/ cation

The element that gives away an electron

Chemical reaction

the process by which atoms or groups of atom in substances are reorganized into different substances

Chemical change

Heat production, light production, cannot be easily reversed(rusting)

physical change

state of matter change, or change in appearance(water boiling, salt dissolving

Chemical equations

Show how elements and compounds change during a chemical reaction

reactants

The left hand side of a chemical equation/ the start

products

The right hand side of a chemical equations/ the end

Protein

Enzymes are a special type of

catalyst

Speed up chemical reactions/ also called enzymes

Anabolic enzymes

Build molecules

Catabolic enzymes

Takes molecules apart

Substrate

The material being changed in an enzyme

Active site

Where substrate connects to the enzyme

lock and key

Enzymes and substrates fit together like

Temperature and pH percent hydrogen

Two main factors that impact enzyme function

pH scale

measured from 0-14

neutral

7 on the pH scale

acidic

less than 7 on the pH scale

basic or alkaline

More than 7 on the pH scale

Acid

Substance that releases H+ (positive hydrogen) ions when dissolved in water

Bases

substance that releases OH (hydroxide) ions when dissolved water

Polar molecules

Molecules that have slight positive and negative charges Ex. water

Hydrogen bonds

A weak attraction between a hydrogen and a fluorine, oxygen, nitrogen atom

van der Waals Forces

A strong type of hydrogen bond

Mixtures

A combination of two or more substances in which each substance retains its individual characteristics and properties

Homogenous mixture

Also called a solution, involves a solvent that dissolves a solute
Uniform appearance ex. salt water

Heterogenous mixture

does not have a uniform appearance ex. trail mix

Polymers

All of the macromolecules are
chemical compounds made of smaller, identical molecules

Monomer

Each smaller molecule that makes up a polymer