2: Chemical Principles

chemistry, atoms, molecules

• study of interactions between atoms and molecules

• _______ is the smallest unit of matter that enters into chemical reactions

• Atoms interact to form ________

energy levels

Atoms are composed of
•Electrons: negatively charged particles
•Electrons are arranged in electron shells corresponding to different ______ _________.
•Protons: positively charged particles
•Neutrons: uncharged particles
•Protons and neutrons= nucleus.
•Electrons= around the nucleus
- # protons= # electrons

protons, neutrons

•Each chemical element has a different number of _________.

•Isotopes of an element are atoms with different numbers of _______.

valence

•Atoms combine to complete the outermost shell.

•The number of missing or extra electrons in this shell is the ________.

carbon (C), hydrogen (H), nitrogen (N), oxygen (O), phosphorus (P) and Sulphur (S)

chemical, electrons

Elements

• 98% of the body weight of organisms has CHNOPS (stands for _________)

• Atomic theory- elements consist of tiny particles called atoms made up of only one kind of atom

• compound- different kinds of atoms

• ________ bonds- forces holding atoms in a compound

• ions- atoms that have gained or lost ______ and are charged.

Ionic bonds

• attractions between ions of opposite charge. One atom loses electrons and another gains electrons

• atoms make these by receiving and giving electron

covalent bonds

• two atoms share one or more pairs of electrons.

hydrogen bonds

a bond between a H atom bonded to O

• indicated by dotted lines

• tetrahedral shape

chemical reactions, Endergonic, Exergonic

• making or breaking of bonds between atoms

• change in chemical energy occurs during a chemical reaction

• _________ reactions absorb energy.

• _________ reactions release energy.

synthesis reactions, Anabolism

• Occur when atoms, ions, or molecules combine to form new, larger molecules

• _________ is the synthesis of molecules in a cell.

decomposition reactions, Catabolism

• Occur when a molecule is split into smaller molecules, ions, or atoms.

• __________ is the decomposition reactions in a cell.

exchange reactions

part synthesis and part decomposition

reversible reactions

• Can readily go in either direction.

• Each direction may need special conditions

Organic, Inorganic

Important Biological Molecules

• ______ compounds always contain carbon and hydrogen.

• ________ compounds typically lack carbon.

Inorganic compound: water

• polar molecule

• solvent

• Polar substances dissociate, forming solutes

• H+ and OH- participate in chemical reactions

Acids, salt, Bases,

• ________ is a substance that dissociates into one or more H+.

• ________- substance that dissociates into cations and anions, neither of which is H+ or OH-

• ______- substance that dissociates into one or more OH-

Acid Base Balance

**• The amount of H+ in a solution is expressed as pH. • pH = -log[H+]

**• Increasing [H+], increases acidity.

**• Increasing [OH-] increases alkalinity.

• Most organisms grow best between pH 6.5 and 8.5.

organic compounds, carbon skeleton, Functional

• The chain of carbon atoms in an organic molecule is the ________ _________.

• __________ groups are responsible for most of the chemical properties of a particular organic compound

amino

Biological importance- proteins

• add picture (31)

phosphate

Biological importance- ATP, DNA

macromolecules, polymers, monomers

organic compounds

• Small organic molecules can combine into large __________.

• Macromolecules are _________ consisting of many small repeating molecules (with covalent bonds).

• The smaller molecules are called _________.

smallest units

1. C6 H12 O6= glucose

2. amino acid

3. glycerol +fatty acid

4. nucleotides

Biological molecules

1. carbohydrates

2. proteins

3. lipid

4. Nucleic acids (DNA, RNA)

glucose

• remember that those same number of elements can be used to form sucrose and fructose

know shape for exam

• carbohydrates, proteins, Nucleic acids

• C6 H12 O6= glucose, amino acid, nucleotides

• macromolecules

• monomers

TO MAKE A BOND, WATER MOLECUELS HAS TO LEAVE

TO MAKE A BOND, WATER MOLECUELS HAS TO LEAVE

dehydration synthesis

organic compounds

• Monomers join by _________ ___________ or condensation reactions

• A

carbohydrates (starch)

• Are important for structure and as energy sources.

• Consist of C, H, and O with the formula (CH2O)n

simple, Polysaccharides, starch, polymers

Carbohydrates

• Monosaccharides are ________ sugars with 3 to 7 carbon atoms.

• Disaccharides are formed when two monosaccharides are joined in a dehydration synthesis.

• Disaccharides can be broken down by B__.

• Oligosaccharides consist of 2 to 20 monosaccharides.

• ___________ consist of tens or hundreds of monosaccharides joined through dehydration synthesis.

• ___________, glycogen, dextran, and cellulose are _________ of glucose that are covalently bonded differently.

• Chitin is a polymer of two sugars repeating many times.

cell membranes, nonpolar

lipids (fats)

• Are the primary components of ________ _________.

• Consist of C, H, and O.

• Are _____ and insoluble in water.

simple lipids, dehydration synthesis, double

•Called fats or triglycerides contain glycerol and fatty acids; formed by ________ ___________. •Unsaturated fats have one or more _____ bonds in the fatty acids.

Complex lipids

• Contain C, H, and O + P, N, or S.

• Membranes are made of phospholipids

Enzymes, Transporter proteins

Proteins

•Are essential in cell structure and function.

•_________ are proteins that speed chemical reactions.

•_______ __________ move chemicals across membranes.

•Flagella are made of proteins.

•Some bacterial toxins are proteins.

•subunits= amino acids (42-43)

Peptide bonds

between amino acids, are formed by dehydration synthesis.

Levels of protein structure

primary, secondary, tertiary, quaternary

primary structure (protein structure)

polypeptide (red line)

secondary structure (protein structure)

occurs when the amino acid chain folds and coils in a regular helix or pleats.

tertiary structure (protein structure)

occurs when the helix folds irregularly, forming disulfide bonds, hydrogen bonds, and ionic bonds between amino acids in the chain.

quaternary structure

consists of two or more polypeptides

nucleic acids, Phosphate,

•Consist of nucleotides.

•Nucleotides consist of a:

• Pentose

• _________ group

• Nitrogen-containing (purine or pyrimidine) base

look at pic (49)

purine

• a nitrogenous base that has a double-ring structure

• adenine and guanine

pyrimidines

•have one ring in their structure

•Thymine and Cytosine

DNA

•Has deoxyribose

•Exists as a double helix

•A hydrogen bonds with T

•C hydrogen bonds with G

RNA

•Has ribose

•Is single-stranded

•A hydrogen bonds with U

•C hydrogen bonds with G

ATP, dehydration synthesis, hydrolysis

•Has ribose, adenine, and 3 phosphate groups •Is made by ________ ________. •Is broken by ___________ to liberate useful energy for the cell.