MBIO 1220 (Essentials of Microbiology) Chapter 2

Define atom.

The smallest chemical unit of matter

Define matter

Anything with a mass, made of atoms

Define element

Matter composed of one type of atom

Define molecule

Two or more atoms combined

Define compound.

Molecule made of two or more different types of atoms

Define proton.

single positive charge

Define electron

Single negative charge

Define neutron

Single neutral charge

Define nucleus

Central portion of an atom, consists of protons and neutrons

Define electron shelf

orbits that electrons are found in surrounding the nucleus

Define ion

Atom that has gained or lost electrons

Define cation

positively charged ion (lost electrons)

Define anion

Negatively charged ion (gained electrons)

Define bonding capacity

Number of covalent bonds an atom can make based on the number of
electrons needed to fill its outer electron shell

Define electronegativity

The tendency of an atom to attract electrons to itself

Define polypeptide

chain of amino acids bound together by peptide bonds

Define peptide bond

Bond between the nitrogen (amino group) of one amino acid and the carbon
(carboxyl group) of the next amino acid in a polypeptide chain

Define purine

nitrogenous base made of 2 rings (adenine, guanine)

Define pyrimidine

nitrogenous base made of 1 ring (thymine, cytosine, uracil)

Define sugar phosphate backbone

Chain of nucleotides bound together by the phosphate of one
bound to the sugar of the nex

Define complementary base pairs

nitrogenous bases that pair up due to the formation of hydrogen
bonds between the. A pairs with T, and G pairs with C

How is a hydrogen bond formed and what is its relative strength?

Two covalently bonded molecules that display polarity are held together and is weak.

How is an ionic bond formed and what is its relative strength?

One atom steals an electron from another atom resulting in a cation and anion. The charges of the ions hold the two atoms together. The strength is greater than hydrogen bonds but weaker than covalent bonds.

How is a covalent bond formed and what is its relative strength?

Atoms share pairs of electrons to complete their outer electron shells. Is very strong.

What are the types of carbohydrates?

Monosaccharides, disaccharides, and polysaccharides.

What are the types of lipids?

Fates, phospholipids, and steroids.

What are the types of nucleic acids?

DNA and RNA

What is steroids made of and its structure?

Hydrocarbon rings in a hydrophobic 4 ring.

What is DNA made of and its structure?

A, T, C, G nucleotides and Double helix consisting of two sugar phosphate backbones with nitrogenous bases in the middle of the helix. Two strands are held together by hydrogen bonds between complementary base pairs

What is RNA made of and its structure?

A, U, C, G nucleotides and is a single strand of nucleotides.

What is monosaccharides made of and its structure?

What is disaccharides made of and its structure?

What is polysaccharides made of and its structure?

What is fat made of and its structure?

What is phospholipids made of and its structure?