Unit 2 Slides AY242

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Chemistry

The study of the chemical and physical interactions of matter, involving about 100 different atoms that create the macroscopic world.

Atom

The basic unit of an element that can enter into chemical combinations; most originated with the birth of the universe.

Atomic Nucleus

The dense center of an atom containing protons and neutrons, accounting for almost all of the atomic mass.

Electron

A negatively charged subatomic particle that resides outside the nucleus and is involved in chemical bonding. Also determine chemical behavior.

Atomic Number (Z)

The number of protons in an atom, which determines the chemical identity of the element.

Mass Number (A)

The total number of protons and neutrons in an atom's nucleus.

Isotope

Atoms of the same element with the same atomic number but different mass numbers due to varying numbers of neutrons.

Valence Electrons

Electrons in the outermost shell of an atom that can participate in bond formation.

Compound

A substance formed when two or more elements combine in definite proportions, often with different properties from the individual elements.

Molecule

A molecular compound consisting of two or more atoms held together by chemical forces.

Ionic Compound

A compound formed from ions in a 3D network, held together by ionic bonds due to the attraction between oppositely charged ions.

van der Waals Forces

Weak attractions between molecules that arise from temporary charge separations due to electron movement.

Polar Molecule

A molecule with a charge separation, leading to slightly positive and negative regions, such as water.

Hydrogen Bond

active interaction between the hydrogen atom in a polar bond with oxygen, nitrogen, or fluorine and another oxygen nitrogen or fluorine atom

Cohesion

The attraction between molecules of the same substance, responsible for surface tension in liquids like water.

Adhesion

The attraction between molecules of different substances, which can be stronger than cohesion in some cases.

pH Scale

A scale that indicates the concentration of hydrogen ions (H+) in a solution, with each step representing a tenfold change.

Organic Chemistry

The study of compounds that contain carbon-to-carbon bonds, focusing on the six most abundant elements in living organisms.

Macromolecules

Large organic compounds found in living cells, formed from smaller molecules through polymerization; includes carbohydrates, lipids, nucleic acids, and proteins.

Amino Acid

The monomer of proteins, consisting of a central carbon atom, an amino group, a carboxyl group, and a variable side chain (R).

Peptide Bond

A covalent bond formed between two amino acids during protein synthesis.

Catalyst

A substance that speeds up a chemical reaction by lowering the activation energy required for the reaction to proceed.

Enzyme

A specific type of protein that acts as a catalyst in biological reactions, facilitating the conversion of substrates into products.

Endergonic Reaction

A reaction that requires energy input to proceed, resulting in a positive change in free energy (ΔG > 0).

lipids

Also known as fats, oils, & waxes. Mostly made from carbon & hydrogen. Cannot form (enough) hydrogen bonds therefore, insoluble in water

Active Site

The area on an enzyme where the substrates react. The environment is more favorable for a reaction.

Substrates

reactants in an enzyme

Protons

part of the nucleus determines atomic number has a positive charge

neutrons

part of the atomic nucleus, neutral charge, provide mass and stability

Core Electrons

Only 2 electrons in core

Covalent Bonds

When molecules share two or more electrons (double bond shares 4) (tripe bond shares 6)

ionic bonds

atoms donate or accept electrons to form ions

solubility of hydrogen bonding atoms

atoms that hydrogen bond mix and dissolve well in water

Heat Capacity

Water can absorb or release a large amount of energy with only a small change in temperature because it can form so many hydrogen bonds

Mixture

combination of two or more substances in which the substances retain their distinct identities

solution

type of mixture where all components are evenly distributed. The solute is dissolved in the solvent.

Suspension

movement of water molecules keep small particles suspended but not fully dissolved

Ionization of water

Water can ionize to form hydroxide ions (OH-) and hydrogen ions (H+). In pure water the concentration of hydroxide ions and hydrogen ions is equal.

acids

forms H+ in solution

base

forms OH- in solution

buffers

Weak acids or bases that help keep the pH stable. This is critical for homeostasis. 

six most abundant elements in living things

carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

How many valence electrons and covalent bonds can hydrogen make

1 valence 1 covalent bond

How many valence electrons and covalent bonds can carbon make

4 valence, 4 covalent bonds

How many valence electrons and covalent bonds can nitrogen make

5 valence, 3 covalent bonds

How many valence electrons and covalent bonds can oxygen make

6 valence, 2 covalent

polymerization

when monomers join together to form polymers

monomer

one molecule in a polymer

polymer

many monomers connected to each other

dehydration synthesis

a water molecule is lost to combine two monomers

hydrolysis

a water molecule is added to split a polymer

carbohydrate

Also known as sugars & starches. Made from carbon, hydrogen, & oxygen, usually in a 1:2:1 ratio. (H - C - OH) It can form hydrogen bonds and, therefore, be soluble in water. Used for storing energy and providing structure

monosaccharide

monomer of a carbohydrate

polysaccharide

polymer of carbohydrates

Cellulose

main structural component of plants

Starch

main energy reserve in plants

Glycogen

functions as an energy reserve for animals

saturated lipids

have all carbon to carbon single bonds (solid at room temp)

unsaturated lipids

at least one carbon-to-carbon double bond (liquid at room temp)

what are nucleic acids made of

carbon, hydrogen, oxygen, nitrogen & phosphorus

nucleic acids

Used for energy (ATP) & storing hereditary information

nucleotide

monomer of nucleic acid

nucleotide chemical structure

5-carbon sugar, Nitrogenous base, 1 to 3 phosphate groups (PO43-)

what are proteins made of

carbon, hydrogen, oxygen, nitrogen, & sulfur

polypeptide

string of amino acids

protein

polypeptide with a function

what are amino acids made of

amino group, side chain, carboxyl group

protein folding primary structure (1o)

amino acid sequence.

protein folding secondary (2o)

folds & coils due to the backbone forming hydrogen bonds.

protein folding tertiary (3o)

three-dimensional shape

protein folding quarternary (4o)

when a functional protein is made up of more than one polypeptide. Not all proteins have 4o structure

chemical reaction

one or more substances are rearranged into one or more new substances. Chemical bonds are broken and new bonds form. Atoms are not created or destroyed, simply reorganized

exergonic reaction

reaction that releases anergy

activation energy

energy input required for a reaction to proceed

what are the four types of macromolecules

carbohydrates, lipids, nucleic acids, proteins