Microbiology Chapter 2

Biochem Definition

understanding the basic principles of chemistry, as they apply to biological systems, is critical to understanding living organisms

What does micro use chem to understand?

• structure & function of microorganisms, their components & life processes

• how microbes interact with humans (positive & negative)

• infectious disease process

• potential for interventions

What is biochemistry?

• science of biology + chemistry

• explore the chem of living organisms and the molecular basis for the complex chemical runs and changes occurring in living cells

• closely related to other molecular scale biological sciences

Metabolism defintion

studies life sustaining intracellular chemical rxns in organisms

Enzymology

studies how proteins called enzymes accelerate chemical reactions

structural biology

studies how biological molecules are assembled, function and interact using a variety of imaging techniques w

what are the 4 major elements that are essential for biological life?

• carbon

• hydrogen

• nitrogen

• oxygen

what is cellular chem dependent on?

ions and small moles and their interaction

cation

postitive charged ions

anions

negative charged ions

ionic bonds

electrons transferred between oppositely charged ions

solvents

dissolving agents

aqueous solutions

water is most common solvent

solutes

dissolved substances

electrolytes

when ionic bond dissolve and release free ions

concentration of a solution

• amount of solute dissolved in a specific volume of solvent

• medication calculation

pH acids

add H+ ions

pH bases

add hydroxide ions (OH)

Buffers

stabilize pH

Neutrophiles

• living organisms are neutrophils

• prefer to live between 6.5-8.5

pH indicators

visually identifiable changes in pH are caused by microbial metabolic activity

MacConkey Agar

• selective & differential in pH identifier

• Lactose, Neutral red

  • selects only certain types of organisms to grow & of those that grow allow us to differentiate

Simmons Citrate Agar

• selective + bromothymol blue

• citrate metabolism = alkaline change (more basic)

  • results in shift of alkaline pH d/t CO2 production

Mannitol Salt Agar

• selective & differential media in pH indicators

• High Salt, mannitol, phenol red

Molecule Defintion

• two or more atoms covalently bonded together & share electrons

molecular formula

elements in molecule & ratios

What does BIOchemistry focus on?

• chemical basis

• assembly

• structure

• functions

• interactions

of biological molecules

what do all biological molecules contain & provide?

• carbon = predominant element of life

• provide cellular structure & perform functions associated with life

organic molecules

• contain C & H

• typically organized around covalently bonded chains of C atoms

• not soluble in water

• large & complex compare to inorganic

Complex biomolecules

• repeating units of covalently linked organic molecules

  • polymerization: Monomers → polymers

• 4 main classes = carbs, lipids, nucleic acids, proteins

What polymer comes from the building blocks of simple sugars?

• polysaccharides

  • complex sugars & starches

What polymer comes from the building blocks of glycerol + fatty acids?

• lipids

• fats, oil & waxes

What polymer comes from the building blocks of nucleotides?

• nucleic acids

• DNA, RNA

What polymer comes from the building blocks of amino acids?

• proteins

• cell structure & enzymes

how are biomolecules produced?

• dehydration synthesis

• uses energy = anabolic

• makes water

How are biomolecules broken apart?

• hydrolysis

• release energy = catabolic

• uses water

what are enzymes role in biomolecules?

• proteins that catalyze rxns

  • name derived substrate or chemical run catalyzed, ends in -ase

Carbohydrate as a biomolecule

• most prevalent biomolecule

• store energy & genetic info; provide structure

• consist of one or more sugar monomers

Monosaccharides

• single sugars built from C, H, O

• general ratio 1:2:1

• Glucose C6H12O6

Disaccharide

• two monosaccharides linked

• formed through dehydration synthesis

• linked by glycosidic bonds

Polysaccharides

• polymerized monosaccharides

• large +/- branching

• complex carbs

carbohydrate microbial function

• energy sources → glycogen, metabolic path

• structural biomolecules

• cellular adhesion

• communication

• environmental sensing

carbohydrate microbial structures

• cellulose = major component of algal cell walls

• chitin = major component of fungal cell walls

• capsules = surface adherence, protection from drying, antibiotics, immune system

• Peptidoglycan, lipopolysaccharide, teichoic acid = critcical bacterial cell wall constitutents

Lipids - Biomolecule

• organic molecule made up of C, H, & O *always even #*

• diverse structure = long chains to cyclical structures

• included fats, oil, fatty acids, maxes, steroids

Lipids primary functions

• transport & store energy - triglycerides

• cell messengers - steroids

• create energy - fatty acid metabolism

• basic building block of biological membranes

  • glycolipids, phospholipids, sterols

Nucleic Acids Biomolecule

• genetic material of cells & viruses (RNA & DNA)

• polymers of nucleotides (contain C, H, O, N, P)

Nucleic Acid Structure

• nucleotide monomers linked into a single strand

• DNA (stable & stores genes)

• RNA (versatile & transfers genetic info for decode)

DNA

• all genetic info for all cellular functions and heredity

• A:T; G:C

RNA

• contains A,G,C or U

• synthesized from DNA on an as-needed basis

• usually single stranded

• transfers gene instructions for decoding, regulate, express, & product proteins

• contains riboenzymes & ribonucleotides

Biomolecules Proteins

• encoded by genes in DNA

• composed of C, H, O, & N atoms (sometimes S)

• primary components of cells

• involved in all cellular processes (chief actors)

primary functions of proteins (biomolecule)

• catalyzing & facilitating metabolic rxns (all enzymes = proteins)

• provide structures to cells & organisms

• cellular signaling & response

• adhesion

• cell recognition & communication

• transport molecs

• dna replication

Proteins - Amino Acids

• proteins are polymers of AA

  • each AA has amine, carboxyl, side group

  • genetically encode basic set of 20 standard amino acids

• AA are covalently linked by peptide bonds

• peptides are short amino acid chains

• polypeptides are long chains of AA

Protein structures

• fold into unique 3D structures (unassisted or assisted)

• able to bind other molecules specifically and tightly

• four levels of protein structure

riboenzymes

specialized RNAs that catalyze rxns

ribonucleotides

energy sources in cell