Microbiology Chapter 2: Biochemistry Basics

Define acid

Substance that contribute hydrogen ions (H+) to a solution

Define amphipathic

A molecule that has both a hydrophilic region and a hydrophobic region.

Define atom

The smallest chemical unit of matter

Define atomic mass

the number of protons and neutrons in an atom

Define atomic number

the number of protons in an atom

Define base

Substances that contribute hydroxide ions (OH-) to a solution

Define chemical bond

The force that holds atoms together

Define functional group

part of a molecule that typically participates in a chemical reaction and that gives the molecule some of its chemical property

Define hydrophilic

water-loving substances that easily dissolve in water

Define hydrophobic

water-fearing substances that do not dissolve easily in water

Define ion

Charged atom formed when an atom loses or gains an electron

Define molecule

two or more atoms joined chemically

Define solution

Mixture of 2 or more substances in which one substance is dissolved within another

Define covalent bond

sharing of electrons

Define hydrogen bond

does not bond atoms into molecules; noncovalent electrostatic attraction between two or more molecules

Define ionic bond

the strong attractive force between ions of opposite charge (between cation and anion)

The ____ is the medium in which substances are dissolved

solution

The substance that is being dissolved is called the ____

Solubility

The most common solvent in living cells is ____

water

The pH scale ranges from __ to __

0 (most acidic) to 14 (most basic)

Neutral level on pH scale

7

Example of a substance with pH of 1

Hydrochloric acid

Example of a substance with pH of 7

pure water

Example of a substance with pH of 14

Sodium Hydroxide

Describe synthesis reactions

builds substances by combining two or more reactants

Describe decomposition reactions

breaks a substance down into simpler components (AB --> A+B)

What can be used for decomposition reaction breakdowns

Water

Define endergonic reaction

require an energy investment to make products that have a higher final energy than the reactants

Define exergonic reactions

Make products with a lower final energy than the reactants

4 major classes of macromolecules

1. Carbohydrates

2. Lipids

3. Proteins

4. Nucleic Acids

What are the building blocks macromolecules

monomers

Single units build large polymers through a process called ____

Polymerization

Define monosaccharide

smallest unit of a carbohydrate and also known as "one sugar"

What is an example of a monosaccharide

glucose, fructose, galactose

Define disaccharide

consists of two monosaccharides joined by a glycosidic linkage "two sugars"

What is an example of disaccharide

sucrose, lactose, maltose

Define polysaccharide

consists of many monosaccharides linked together "many sugars"

What is an example of polysaccharide

starch, glycogen, cellulose

What is a triglyceride composed of?

1 glycerol and 3 fatty acids

What is a phospholipid composed of?

a glycerol backbone, two fatty acid chains, and a phosphate group

The basic building block of a protein is what?

amino acid

How are proteins bonded?

peptide bonds

What is an amino acid composed of?

carboxyl group, amino group, variable side chain (R group)

Define primary structure

Linear sequence of amino acids in a protein.

Define secondary structure

The twisting of a polypeptide into either an alpha helix or beta-pleated sheets

Define tertiary structure

The folding of a polypeptide into a three-dimensional structure

Define quaternary structure

The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.

3 functions of proteins

structural scaffolds, enzymes, cellular transporters

components of a nucleotide

phosphate group, 5 carbon sugar, nitrogenous base

Sugars in DNA

deoxyribose

Sugars in RNA

ribose

Bases of DNA

Adenine, Thymine, Guanine, Cytosine

The bases of RNA are...

adenine, cytosine, guanine, uracil

What is the "strandedness" of DNA

double stranded helical

What is the "strandedness" of RNA

single stranded

What type of bonds are carbohydrates built with?

Glycosidic bond

What type of bonds are Lipids built with?

Ester bond

What type of bonds are Nucleic Acids built with?

Phosphodiester bond

What type of bonds are proteins built with?

Peptide Bond