Honors Biology (Unit 1)

Chapter 2 (Sections 2.1-2.4) -> Chapter 3 (Sections 3.1-3.5) -

Matter

Anything that takes up space and had mass

Element

A substance that can’t be broken down by chemical reactions

Compound

A substance made of 2 or more different elements combined in a fixed ratio

Essential Element

Elements an organism needs to live and reproduce

Trace Element

An element that’s required in small quantities

Atom

The smallest unit of matter that keeps the traits of an element

Proton

An electric subatomic particle with a positive charge

Neutron

A neutral subatomic particle

Electron

An electric subatomic particle with a negative charge

Atomic Nucleus

Where protons and Neutrons are found in an atom

Dalton/amu

the unit for measuring atoms/subatomic particles

Atomic number

the number of protons in an element’s nucleus

Mass number

Total number of protons and neutrons in an atom

Atomic Mass

The mass of an atom - very close to mass number

Isotopes

Specific atoms that have more neutrons than others of their element

Radioactive isotope

An isotope who’s nucleus spontaneously decays → changes the number of protons → changes the number of electrons

Energy

The ability to cause change

Potential Energy

Energy gained because of location or structure

Electron shell

Where electrons are found - each has a special distance from the nucleus and energy level

Valence Electrons

The electrons in the outermost shell

Valence shell

The outermost shell

Chemical Bonds

The bond between atoms

Covalent Bonds

Sharing a pair of valence electrons

Molecule

2 or more atoms held together by covalent bonds

Single bond

bonds pair of shared electrons

Double bond

O=O, 4 electrons shared

Valence

An atom’s bonding capacity/ the # of covalent bonds an atom can form

Electronegativity

The attraction/strength of a particular atom’s electrons

Non polar covalent bond

when 2 atoms of the same element bond - electrons are shared equally

Polar Covalent Bond

when an atom is bonded to a more electronegative atoms - electrons not shared equally

Ion

When 2 atoms have such unequal electronegativity, one takes an electron

Cation

A positively charged ion

Anion

a negatively charged ion

Ionic bond

a bonded cation and anion

Ionic compounds/salts

Compounds formed of ionic bonds

Hydrogen bond

Non-covalent attraction between an electronegative atom and a H atom

Van Der Waals interactions

What enables different atoms to stick together

Chemical Reaction

The making and breaking of chemical bonds

Reactants

The starting materials in a chemical reaction

Products

The resulting materials from a chemical reaction

Chemical Equilibrium

The point when the forward and reverse reactions between reactive atoms offset each other and reach a steady rate or ratio.

Hydrocarbon

Organic molecules made of Carbon and Hydrogen

Isomer

Has the same number of atoms as its same element, but a different molecular structure.

Structural Isomers

Isomers with a different covalent arrangement of atoms

Cis-trans Isomers

They have covalent bonds between the same atoms, but they differ in spacial arrangement because of the addition of double bonds.

Enantiomers

Mirror-Image isomers that differ in shape because of their central asymmetric carbon, which is attacked to 4 different atoms.

Functional Groups

chemical groups that directly affect chemical function

Adenosine Triphosphate (ATP)

an adenosine attached to 3 phosphate groups

Polymer

A long molecule made of similar or the same building blocks bonded by covalent bonds

Monomer

The building blocks of polymers

Enzyme

Macromolecules that speed up chemical reactions

Dehydration Reaction

When monomer bonds lose a water molecule → helps to destroy polymers

Hydrolysis

A reaction that creates a water molecule and breaks monomer bonds.

Carbohydrates

Sugars or polymers of sugar

Monosaccharide

A simple sugar, which bonds with others to create complex carbs

Disaccharide

2 monosaccharides joined by a glycosidic linkage

Glycosidic linkage

a covalent bond between monosaccharides formed by a dehydration reaction

Polysaccharide

A macromolecule of 100-3,00 monosaccharides joined by glycosidic linkages

Startch

A polymer of glucose monomers, acts as a storage polysaccharide

Glycogen

A branched complex startch

Cellulose

A part of a plant cell’s wall - Acts as a structural polysaccharide

Chitin

A carb used by arthropods to build their exoskeletons

Lipid

Compounds that mix poorly or not at all with water - Not a polymer

Fat

A lipid made of glycerol

Fatty Acid

Has a long carbon skeleton with 16-18 carbon atoms, with a carboxyl group on one end

Triacylgylcerol

3 fatty acids bonded with a glycerol by an ester linkage (bond between a hydroxyl and carbonyl group)

Saturated Fatty Acid

A fatty acid with a high saturation of hydrogen

Unsaturated Fatty Acid

A fatty acid with 1 or more double bonds, with one fewer Hydrogen atoms on each double bond.

Trans Fats

Created when unsaturated fats are synthetically converted to saturated fats

Phospholipid

Similar to a fat molecule, but with only 2 fatty acid molecules instead of 3.

Steroid

A lipid with a carbon skeleton of 4 fused rings

Cholesterol

A component of cell membranes and a building block of other steroids.

Catalyst

Chemical agents that speed up chemical reactions with out being consumed

Polypeptides

The polymer version of a peptide bond between aminos

Protein

A functional molecule made of 1 or more polypeptides

Amino Acidd

An organic molecules with an amino and carboxyl group

Peptide Bond

The covalent bond that results from two amino acids whose carboxyl groups are adjacent - joined by a dehydration reaction.

Primary Structure

A sequence of amino acids

Secondary Structure

The oils and folds of proteins

Polypeptide Backbone

The base of a peptide - not the side groups

a helix

A coil held together by Hydrogen bonds between every 4th amino acid

B pleated sheet

2 or more polypeptide chains adjacent to each other connected by Hydrogen Bonds

Tertiary Structure

The overall shape of a polypeptide because of the interactions between their side chains.

Hydrophobic Interactions

Contribute to tertiary structure - the hydrophobic atoms move to the center of the protein, and the exclusion of non polar toms causes van Der Waals interactions, while polar molecules have their own interactions on the outside.

Disulfide Bridges

Covalent bonds that reinforce the shape of a protein

Quaternary Structure

The overall protein structure that results from the aggregation of 2 or more polypeptide chains.

Sickle Cell Disease

An inherited blood disorder causes by switching 1 amino acid for a normal acid in a hemoglobin.

Denaturation

When a protein loses its native shape, which makes its structure biologically inactive.

X-Ray crystallography

The best way (currently) to determine the 3D shape of a molecule.