A&P 1 (summer) chapter 2

Covalent bonds

formed by sharing of two or more valence shell electrons between two atoms. (Nonpolar covalent bond, Polar covalent bond)

Nonpolar covalent bond

equal sharing of electrons between atoms

Polar covalent bonds

Unequal sharing of electrons between atoms results in electrically polar molecules.

Hydrogen bonds

An attractive force between the electropositive hydrogen of one molecule and an electronegative atom of another molecule.

Exergonic reaction

Reactions that result in a net release of energy (give off energy)

Endergonic reaction

Reactions that result in a net absorption of energy (use up energy). Products have more potential energy than reactants

Ionic bonds

the transfer of valence shell electrons from one atom t another, resulting in ions

ions

atoms that have gained or lost electrons and become charged.

Acids

proton donors: they release hydrogen ions (H+)

Bases

Proton acceptors: they pick up H+ ions in solution (from the release of OH-)

Carbohydrates

includes sugars and starches (contain C, H, and O)

Lipids

contain C, H, O, and sometimes contain P, insoluble in water.

Types of lipids:

triglycerides, Phospholipids, Steroids

Trans fats

modified unsaturated fatty oils that resemble the structure of saturated fats and are considered unhealthy

triglycerides

composed of three fatty acids bonded to a glycerol molecule by dehydration synthesis

triglyceride uses

mainly used for energy storage, insulation, and protection

Phospholipids

modified triglycerides, glycerol, and two fatty acids plus a phosphorus-containing group.

purpose of phospholipids

important in cell membrane structure

steroids

consists of four interlocking ring structures (the most important steroid is cholesterol)

puprose of steroids

important in cell plasma membrane structure

proteins

contains C, H, O, N, sometimes S and P, polymers of amino acid monomers held together by peptide

structural levels or proteins (primary)

Linear sequence of amino acids (order)

structural levels of proteins (secondary)

How many primary amino acids interact with each other

Structural levels of proteins (tertiary)

how secondary structures interact

Structural levels of proteins (quaternary)

how 2 or more different polypeptides interact with each other.

Nucleic acids

composed of C, H, O, N, P. made up of a nitrogen base, pentose sugar, and a phosphate group

Deozyribonucleic acid (DNA)

genetic blueprint for the synthesis of all proteins. Double-stranded helical molecule (double helix) located in cell nucleus .

RNA

Links DNA to protein synthesis and is slightly different from DNA