Matter - anything that has mass and takes up space.
Element - Matter in its simplest form
Atom - the smallest form of an element that still displays particular properties.
Ion - An atom with a negative or positive charge.
Cation - ion with positive charge; composed of more protons than electrons.
Anion - ion with negative charge; composed of more electrons than protons.
Elements can be combined to form molecules. For eg: An oxygen molecule.
Compounds - molecules that are composed of more than one element. For eg: H2O.
Organic compounds - contain carbon and usually hydrogen; Inorganic compounds do not.
Functional Groups - The groups responsible for the chemical properties of organic compounds.
Amino group: Has the following formula:
Inorganic compound consisting of one oxygen molecule covalently bonded to two hydrogen bonds.
Electrons shared between the hydrogen and oxygen molecules are closer to the oxygen molecule due to its electronegativity.
Results in the oxygen molecule being negatively charged and the hydrogen molecule being positively charged.
Water molecules - polar because they have a positive and negative side.
Non Polar molecules - neutral charge due to equal sharing of electrons.
Hydrogen bonding - the attraction between a positively charged hydrogen atom and any other electronegative atom (eg: oxygen).
May form between atoms within the same molecule or between two separate molecules.
Water molecule - contains slightly positive charged hydrogens and slightly negative oxygen molecules, allowing it to form up to two hydrogen bonds with other water molecules, leading to a variety of properties unique to water.
Properties of Water
Water molecules linking together due to hydrogen bonds
Surface tension - the surface of water is difficult to break or stretch.
A water molecule is attracted to other substances due to hydrogen bonds.
The adhesion of water to plant cell walls by hydrogen bonds help counter the pull of gravity in plants.
The surface of an object becomes cooler during evaporation as a result of water absorbing energy in the form of heat.
Evaporation of sweat from the skin of humans lowers body temperature.
Surface tension allows water to be resistant to external forces, due to the cohesive nature of water molecules to one another instead of the surrounding molecules in the air.
Water dissolves more substances than any other liquid of Earth.
Phospholipid - lipid formed by combining a glycerol molecule with two fatty acids and a phosphate group.
Phospholipids - amphipathic structures - they have both a hydrophobic tail (a hydrocarbon chain) and a hydrophilic head (the phosphate group)
Major component of cell membranes; hydrophilic phosphate group - forms the outside portion, hydrophobic tail - forms the interior of the wall.
Structure of phospholipid
Bilayered structure of phospholipids
Simple sugars or complex molecules containing multiple sugars.
Used by the cells of the body in energy-producing reactions and as structural materials.
Have the elements C, H, and O. Hydrogen and oxygen are present in a 2:1 ratio.
Main types of carbohydrates - monosaccharides, disaccharides, and polysaccharides.
Monosaccharide - simple sugar, the purest form of a carbohydrate. (glucose - C6H12O6)
Monosaccharides with five carbons (C5H10O5) are used in compounds such as genetic molecules (RNA) and high-energy molecules (ATP).
Disaccharide - sugar consisting of two or more monosaccharides bound together.
Common disaccharides - sucrose, maltose, and lactose.
Sucrose, a major energy carbohydrate in plants, is a combination of fructose and glucose; maltose, a carbohydrate used in the creation of beer, is a combination of two glucose molecules; and lactose, found in dairy products, is a combination of galactose and glucose.
Polysaccharide carbohydrate containing three or more monosaccharide molecules.
Usually composed of hundreds or thousands of monosaccharides, act as a storage form of energy, and as structural material in and around cells.
The most important carbohydrates for storing energy - starch and glycogen.
Starch - made solely of glucose molecules linked together, is the storage form of choice for plants.
Animals store much of their carbohydrate energy in the form of glycogen, often found in liver and muscle cells. Glycogen is formed by linking many glucose molecules together.
Two important structural polysaccharides - cellulose and chitin.
Cellulose - a compound composed of many glucose molecules, used by plants in the formation of their cell walls.
Chitin - an important part of the exoskeletons of arthropods such as insects, spiders and shellfish.
Compound composed of chains of amino acids.
Functions in the body — serve as structural components; transport aids, enzymes, and cell signals.
An amino acid consists of a carbon center surrounded by an amino group, a carboxyl group, a hydrogen, and an R group.
R stands for rest of the compound, which provides an amino acid’s unique personal characteristics; Acidic amino acids have acidic R groups, basic amino acids have basic R groups, and so forth.
Structure of an amino acid
Amino acid structure exhibiting peptide linkage
Structures of proteins
Primary structure - the order of amino acids that make up the protein
Secondary structure - three-dimensional arrangement of a protein caused by hydrogen bonding at regular intervals along the polypeptide backbone.
Tertiary structure - three-dimensional arrangement of a protein caused by interaction among the various R groups of the amino acids involved.
Quaternary structure - the arrangement of separate polypeptide subunits into a single protein. Not all proteins have a quaternary structure; many consist of a single polypeptide chain.
Fibrous proteins - proteins with only primary and secondary structure
Globular proteins - proteins with only primary, secondary, and tertiary structures
Either fibrous or globular proteins may contain a quaternary structure if there is more than one polypeptide chain.
Deoxyribonucleic acid (DNA) - composed of four nitrogenous bases: adenine, guanine, cytosine, and thymine.
Adenine and guanine - a type of nitrogenous base called a purine, contain a double ring structure.
Thymine and cytosine - a type of nitrogenous base called a pyrimidine, contain a single-ring structure.
Scientists James D. Watson and Francis H.C. Crick - given credit for realizing that DNA was arranged in what they termed a double helix composed of two strands of nucleotides held together by hydrogen bonds.
Adenine always pairs with thymine (A=T) held together by two hydrogen bonds; guanine always pairs with cytosine (C≡G) held together by three hydrogen bonds.
Each strand of DNA consists of a sugar-phosphate (sugar - deoxyribose) backbone that keeps the nucleotides connected with the strand.
The two strands of a DNA molecule run antiparallel to each other; the 5′ end of one molecule is paired with the 3′ end of the other molecule, and vice versa.
The 5’ and 3’ ends in DNA structure.